Naval Postgraduate School
Calendar | Directory
banner
Research Projects From 2000 to 2001

2001

DIGITAL TARGET IMAGING ARCHITECTURES

Phillip E. Pace, Professor

Douglas J. Fouts, Associate Professor

Department of Electrical and Computer Engineering

Sponsor: Office of Naval Research, Washington DC

 

OBJECTIVE: The technical objective of this research is twofold. The first objective is to quantify the system-level implementation tradeoffs of a digital, programmable imaging architecture to generate realistic false target signatures against high resolution imaging radars, including synthetic aperture radar (SAR) and inverse SAR (ISAR), using all-digital techniques and modern digital radio frequency memory (DRFM) technology. The second objective is to design, fabricate and test an all digital target imaging device capable of generating large false targets using wideband chirp signals of any duration to provide a new, superior, radio frequency (RF) decoy capability.

 

SUMMARY:  A sequence of simulations was completed to quantify various different design tradeoffs in the high-level architecture of the digital image synthesizer (DIS).  The simulations were started during the previous year’s effort of this 3-year project.  Based on the simulation results, a new, high-performance architecture was developed for the DIS.  The design of a high-speed CMOS application-specific integrated circuit (ASIC) that implements the new architecture was then started.  The design of this ASIC is now more than half completed, including schematic capture, circuit simulation, mask layout, design rule checking, layout verification, and logic simulation.  Simulations indicate the ASIC will function correctly at clock speeds of up to 780 MHz, well beyond the 600 MHz target frequency of the baseband signal.  An interface circuit is also being developed to interface the ASIC with a new type of DRFM being developed at the Naval Research Laboratory.

PUBLICATIONS:

D.J. Fouts, P.E. Pace, C. Karow, and S. Ekestorm, “A Single Chip False Target Radar Image Generator for Countering Wideband Imaging Radars”, IEEE Journal of Solid State Circuits, (accepted for publication).

P.E. Pace, D.J. Fouts, S. Ekestorm and C. Karow, “Digital False Target Image Synthesizer for Countering ISAR,” IEE Proceedings – Radar, Sonar and Navigation (to be published).

PRESENTATIONS:  

P. E. Pace and D. J. Fouts, “Digital Target Imaging Architecture for Multiple Large-Target Generation,” Presented to the Office of Naval Research, Electronic Warfare Science & Technology Gatherings, Washington DC, May 9, 2001.

P. E. Pace, D. J. Fouts, C. A. Amundson and C. Guillaume, “Digital Target Imaging Architecture for Multiple Large-Target Generation: Critical Design Review,” Presented to the Naval Research Laboratory, Washington DC, September 6, 2001.

D. J. Fouts and P. E. Pace, “Digital Target Imaging Architecture for Multiple Large-Target Generation: Progress Report,” Presented to the Office of Naval Research, Washington DC, December 19, 2001.

THESIS DIRECTED:

K.M. Kirin, “VLSI Design of Sin/Cos Lookup Table for Use With Digital Image Synthesizer ASIC”, MSEE Thesis, June 2001.

C.A. Amundson, “Design, Implementation, and Testing of a High Performance Summation Adder for Radar Image Synthesis”, MSEE Thesis, September 2001.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, Electronics, Computer and Software.

KEYWORDS: Imaging decoys, inverse synthetic aperture radar, counter-targeting, counter-terminal, digital radio frequency memories, DRFM.

 

DETERMINING AN OPTIMUM SENSOR NETWORK CONFIGURATION

Phillip E. Pace, Professor

Department of Electrical and Computer Engineering

Sponsor: NAVAIR

 

OBJECTIVE: This proposal investigates using the Advanced Reactive Electronic Warfare Simulation (ARES) to determine optimum sensor network configurations for applications in electronic attack (EA) and suppression of enemy air defense (SEAD).

SUMMARY As a first step, appropriate measures of effectiveness (MOE's) were developed in order to define the fitness of a sensor network.  For example, a "perfect" sensor network would know everything about the environment with 100% accuracy instantaneously. Appropriate MOE's, therefore, would optimize the sensor network (radars and ESMs) toward perfection (e.g., minimize latency, maximize information content).  Working closely with Code 5700 the developed MOE's were embedded into the ARES. The various MOE's were tested to quantify the sensitivity of the solution to (a) the choice of MOE, and (b) the application. From this we determined if there was an overall best MOE for optimizing the sensor network. The optimized sensor network was applied to several engagement problems (EA and several types of SEAD) in order to determine how well network supported the application.

THESIS DIRECTED:  

Pham, Phuong N., “Sensitivity Analysis Of An Optimum Multi-Component Airborne Electronic Attack Configuration For Suppression Of Enemy Air Defense, Masters Thesis SECRET, Naval Postgraduate School, March, 2001.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, Electronics, Modeling and Simulation

KEYWORDS: Electronic attack, network-centric warfare, optimum sensor configuration, measures of effectiveness.

 

OPTIMUM SENSOR NETWORK CONFIGURATION FOR SEAD

Phillip E. Pace, Professor

Department of Electrical and Computer Engineering

Sponsor: Johns Hopkins University, Applied Physics Laboratory

 

OBJECTIVE: This proposal continues the investigation using the Advanced Reactive Electronic Warfare Simulation (ARES) to determine optimum sensor network configurations for applications in electronic attack (EA) and suppression of enemy air defense (SEAD).

SUMMARY: A sensitivity analysis of the solution evolved by simulation was performed in order to determine the robustness in the derived measures of effectiveness to system failures or variances in the performance parameters.  The tasks involved with this effort included simulating the RT-4 distributed scenarios to baseline the corresponding measure of effectiveness (i.e., target engagement time by surface-to-air missile site). One or more parameters in the scenario solution were then changed (receiver dynamic range, jamming assignment, etc) and the measures of effectiveness were rederived in order to investigate their sensitivity to these changes. In addition, this project developed a User’s Guide for the Naval Research Laboratory (NRL) Advanced Reactive Electronic Warfare Simulation (ARES) software Version 1.12 used in the analysis.

PUBLICATIONS: 

Pace, P.E., Wickersham, D., Jenn, D., and York, N., “High resolution phase sampled interferometry using symmetrical number systems, IEEE Transactions on Antennas and Propagation,” Vol. 49 No. 10 pgs. 1411-1423, Oct. 2001.

THESIS DIRECTED: 

Pham, Phuong N., “Sensitivity Analysis Of An Optimum Multi-Component Airborne Electronic Attack Configuration For Suppression Of Enemy Air Defense, Masters Thesis SECRET, Naval Postgraduate School, March, 2001.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, Electronics, Modeling and Simulation

KEYWORDS: Electronic attack, network-centric warfare, optimum sensor configuration, measures of effectiveness.

 

REVOLUTION IN BATTLESPACE TECHNOLOGIES WORKSHOP 2001

Phillip E. Pace, Professor

Department of Electrical and Computer Engineering

Sponsor: Swedish National Defence College

 

OBJECTIVE: This 3-week course hosted by the NPS Center for Joint Services Electronic Warfare, is intended for international military officers and technical research personnel who are interested in the technologies of command and control warfare (C2W). 

 

SUMMARY: The course was sponsored by the Swedish National Defence College (SNDC), and ordered through the Security Assistance Office at the American Embassy in Stockholm under MASL P179220.  This year, the workshop was held from 23 Apr through 11 May 2001.  A total of 31 NDC students and 8 supporting SNDC staff (including Brigadier General Bjorn Andersson) attended the workshop. All course materials and textbooks were supplied to the students. During the first week there was an Opening Reception and a photo taken of all participants in the course. Each student received a Chambray (soft denim) commemorative shirt with the workshop course logo. A field trip to Condor Systems was also taken during the second week. A Flag Dinner and Graduation Ceremony and Dinner were held in week three. Upon completion of the course, students received a Certificate of Graduation. All course materials were mailed back to SNDC upon completion of the course.

PUBLICATIONS:

Advanced Technical Workshop 2001: Revolutions in Battlespace Technology Volumes I-IV, Center for Joint Services Electronic Warfare, 23 April – 11 May, 2001.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, Electronics, Modeling and Simulation

KEYWORDS: Workshop, Short courses, Technology, NPS Center for Joint Services Electronic Warfare 

 

NAVY SURFACE ANTI-SHIP CRUISE MISSILE THREAT SIMULATOR VALIDATION WORKING GROUP

Phillip E. Pace, Professor

Department of Electrical and Computer Engineering

Sponsor: Naval Research Laboratory, Washington DC

 

OBJECTIVE: The objective of this proposal is to provide technical leadership to the Navy Surface Anti-Ship Cruise Missile Threat Simulator Validation Working Group. Three types of simulations are currently being validated by the SVWG for use in test and evaluation. These include (a) radio frequency missile hardware simulators, (b) infrared missile hardware simulators and (c) computer models of missile seekers and related electronics.

SUMMARY:  The duties for the SVWG chairman include coordinating with the Navy’s Simulator Validation Coordinator, the NRL ENEWS Program Manager and other Navy commands (e.g., Commander Operational Test and Evaluation Force) to prioritize the simulator validations for N912 approval.  Additional responsibilities include coordinating with the Office of Naval Intelligence for threat data review and convening the SVWG as an independent and unbiased reviewer for all of the validation reports.

PUBLICATIONS:

Pace, P.E., Zulaica, D., Nash, M.D., DiMattesa, A.D., and Hosmer, A.C., “Relative targeting architectures for captive-carry HIL missile simulator experiments,” IEEE Transactions on Aerospace and Electronic Systems, Vol. 37, No. 3, pgs. 810-823 July 2001.

P. E. Pace, “Adaptive Power-Managed FMCW Emitter Detection Performance Against Low-RCS Ships,” Proceedings of the IEEE Thirty Fifth Asilomar Conference on Signals, Systems and Computers,” MP8b, Monterey, CA, Nov. 2, 2001.

PRESENTATIONS:  

P. E. Pace, “Infrared Systems and Analysis,” Presented at the N9 Threat ASCM Simulator Validation Working Group,” Naval Research Laboratory, June 26, 2001.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, Electronics, Computer and Software

KEYWORDS: Anti-ship cruise missiles, simulators, captive-carry, hardware-in-the-loop.

 

MAGNETIC FIELD SENSOR PLACEMENT 

AND TIME-REVERSED EM IMAGING STUDIES

Michael A. Morgan, Professor

Department of Electrical and Computer Engineering

Sponsor: Office of Naval Research

 

OBJECTIVES:  This project included two independent investigations, each of which formed the topic of an M.S. Thesis.   The first topic sought to optimize near-surface sensor placements to increase the prediction accuracy of magnetostatic near-fields surrounding ferromagnetic objects. Time-reversed wave equation solutions in accoustics were extended to electromagnetics in the second topic, with application to radar imaging.

SUMMARY:  Progress for the first topic included:  (1) development of a modal algorithm for the field solution due to an axial array of dipoles enclosed within a ferromagnetic spheroidal shell;  (2) testing with additive noise of an SVD based least-squares field prediction algorithm using point sensor data, and; (3) extensive searches for optimal sensor placement configurations and the cataloging of findings.   Progress for the second topic included development of a finite-difference time-domain simulation and evaluation of imaging accuracy for various levels of noise and sparsity of boundary data. 

CONFERENCE PRESENTATIONS:

M. A. Morgan and D.G. Steenman (LT, USN), "Null Spaces for Near-Field Imaging," 2001 URSI National Radio Science Meeting, Boston, MA, July 10, 2001.

M. A. Morgan, S.W. Yopp (LT, USN) and A.V. Kildishev, “Optimal Sensor Placement for Magnetic Signature Prediction,” 2001 Intermag Symposium, Amsterdam, Netherlands, 2 May 2001.

A.V. Kildishev, J. A. Nyenhuis,and M. A. Morgan, “Multipole Analysis of an Elongated Magnetic Source by a Cylindrical Sensor Array,” 2001 InterMag Symposium, Amsterdam, Netherlands, 2 May 2001.

THESIS DIRECTED:

Yopp, Stacey W, “Magnetic Field Estimation Using Optimal Locations of Near Field Sensors,” Master’s Thesis, June 2001.

Inaba, Yosuke, “Radar Target Imaging Using Time-Reversed Processing,” Master’s Thesis, September 2001.

DoD KEY TECHNOLOGY AREAS:  Sensors, Modeling and Simulation

KEYWORDS:  Optimal Sensor Placement, Magnetostatic Field Prediction, Time-Reversed Electromagnetics, Radar Imaging 

 

MODELING AND SIMULATION OF IMPULSIVE Radiation 

and Propagation

Michael A. Morgan, Professor

Department of Electrical and Computer Engineering

Sponsor: NSWC

 

OBJECTIVE: The goal of this task is to investigate the impulse radiation characteristics of specified antennas in the presence of buildings over real earth

SUMMARY: Wire-grid numerical modeling of antenna and building structures has been completed using frequency-stepped calculations using the Numerical Electromagnetics Code (NEC-4).   Impulsive near-fields within the modeled building are found using time-domain source modeling and inverse FFT convolution.   Animations of fields within the structure are created using custom MatLab programs.

CONFERENCE PRESENTATION:

M.A. Morgan, "Impulsive Field Computation and Measurement," 2001 URSI National Radio Science Meeting, Boston, MA, July 10, 2001. 

DoD KEY TECHNOLOGY AREA: Modeling and Simulation

KEYWORDS: Impulse response, antenna modeling, near-fields, NEC

 

GUSTY YEARLING, TASK A

Michael A. Morgan, Professor

Department of Electrical and Computer Engineering

Sponsor: NELO

 

This is a TS level compartmented Special Access Project. No accurate description can be provided for publication in this forum.

 

 

EVALUATION OF  MBL PROFILE ESTIMATION AND ESTIMATING EM/EO FACTORS FOR TO OPERATING FORCES

K. L. Davidson, Professor of Meteorology

Sponsor:  Space and Naval Warfare Command, SPAWAR PMW 155

 

OBJECTIVE: Validate/verify the Tactical Drop-sondes (TDrop) to meet requirements for accurate and tactically significant measurements of temperature, moisture, and pressure within the lower marine atmosphere and evaluate technical information transfer and application for refractivity effects on CG’s.

SUMMARY: Evaluation was performed to evaluate the performance of the in situ application on other methods, i.e. Lidar, M_AERI, on-board sensor, for estimating refractivity profiles, continuously. Further, to explore properties of near-surface layer with kite-borne sensors for purpose of evaluate sensor goals. The Naval Postgraduate School (NPS) carried out analyses of application of its near-surface refractivity model for inclusion within the SMOOS(R) system. This model computes near-surface refractivity profiles and the evaporation duct height from environmental measurements provided by the shipboard SMOOS(R) measurement system. The model refractivity profiles can then be input into propagation assessment programs such as AREPS to predict near-surface radar performance in the current environment, including the probability of detection of specific threats. The NPS model has been incorporated into the AREPS and into SMOOS(R) system software developed by the Johns Hopkins University, Applied Physics Laboratory (JHU/APL). NPS and JHU/APLpersons prepared a draft “rules of thumb” document for AG’s and Radar Systems Controllers for “Guidance for METOC Persona to aid AN/SPY-1 radar operators in evaluating environmental conditions

REPORTS/PUBLICATIONS:

Davidson, K. L., and P. A. Frederickson, “METOC Description and Rf/EO Propagation.”  Modernizing METOC Support to the Surface (AEGIS) Warfighter, Pearl Harbor, Hawaii, 22-23 February 2001.

Davidson, K. L., and P. A. Frederickson, “METOC Sampling for Rf/EO Propagation Assessment.”  Modernizing METOC Support to the Surface (AEGIS) Warfighter, Pearl Harbor, Hawaii, 22-23 February 2001.

Davidson, K. L. and P. A. Frederickson, “Estimating Near-Surface Atmosphere Properties that Affect Weapons Systems,“ NPS Research, Featured Article, June 2001, pp10-13 & 57-58.

Davidson, K. L. “Effects and Estimation of Near-surface atmosphere effects on Rf/EO propagation/system performance,” Simulation Validation Working Group (SVWG) Bi-Annual Meeting,  Naval Research Laboratory, Washington, D.C. 26-28 June , 2001.

Frederickson, P. A., K. L. Davidson, J. Stapleton, D, Shanklin, R. Wiss, T. Nguyen, E. Burgess III, C. Weeks, W. Thornton, and T. Brown, “Validation of AREPS Propagation Assessments Using Different Evaporation Duct Models.”  Battlespace Atmospheric and Cloud Impact on Military Operations (BACIMO 2001) Conference, Fort Collins, Colorado, 10-12 July 2001.(Army Research Laboratory CD-ROM ARL-SR-01126, October 2001).

Frederickson, P. A., K. L. Davidson, J. Stapleton, D, Shanklin, R. Wiss, T. Nguyen, E. Burgess III, C. Weeks, W. Thornton, and T. Brown, “Validation of AREPS Propagation Assessments Using Different Evaporation Duct Models.”  Ship Based Defense Demonstration, IAFCSE Task – MPME Wallops 2000 Final Review, Naval Surface Warfare Center, Dahlgren, Virginia, 3 October 2001.

THESIS DIRECTED:

Sommer, William L., “Difficulties in Identifying and Evaluating Surface-based and Evaporative Duct Impacts,” NPS MS Thesis, March 2001, 136 pp.

Eckardt, Marc C., “Assessing the Effects of Model Error on Radar Inferred Evaporative Ducts,” NPS MS Thesis, March 2002, 170 pp.

Robinson, Sean D., “Case Study Supporting the Usefulness of TEP as a Naval Mesoscale Weather Radar , “ NPS MS Thesis, March 2002 (in progress)

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer.

DOD KEY TECHNOLOGY AREAS:  Battlespace Environments, Sensors

 

METOC DATA ACQUISITION (MORIAH/SMOOS(R))

K. L. Davidson, Professor of Meteorology

SPONSOR: Sponsor:  Space and Naval Warfare Command, SPAWAR PMW 185

 

OBJECTIVE: Support acquisition strategy of a shipboard Meteorology and Oceanography parameter sensor system, MORIAH, by carrying out validation, verification and integration procedures. Prepare software documentation for acquisition and evaporation duct calculation.

SUMMARY: NPS evaluated and documented performance characteristics of MORIAH hardware and Software for use in the complex METOC and electronic environment of a Navy warship.  These were also done for MORIAH like systems mounted on buoys deployed in coastal regimes in support of propagation tests. System performance evaluation was of characteristics of both the MORIAH hardware and acquisition and calculation/editing software. The algorithm  for  evaporation duct refractivity profiles using SMOOS(R)-type data was evaluated with buoy-based data collected in collection associated with the NSWC-DD directed   Ship-Based Defense Demonstration, IAFCSE Task – MPME ( Wallops1998& 2000), Sommers 2001, and Frederickson et al 2001. The SMOOS( R) acceptable errors for all airflow and surface properties were used in an evaluation of the impact of the neutral profile assumptions within the Refractivity from Clutter (“RFC”) procedure, Eckardt 2002.

REPORTS/PUBLICATIONS:

Frederickson, P.A., K.L. Davidson, F. Keith Jones, and Deborah L. Mabey, “SCI 2001 Sensor Technology Test ; Preliminary METOC Data Atlas,” NPS Technical Report, 19 December , 2001, 83 pp.

Frederickson, P. A., K. L. Davidson, F. Keith Jones, and Tamar Neta, “NPS FLUX Buoy Data Report for the MUSE Deployment, August - September 2000,” NPS Technical Report, 5 April 2001, 19 pp.

Davidson, K. L. and P. A. Frederickson, “Estimating Near-Surface Atmosphere Properties that Affect Weapons Systems,“ NPS Research, Featured Article, June 2001, pp10-13 & 57-58.

THESIS DIRECTED: 

Sommer, William L., “Difficulties in Identifying and Evaluating Surface-based and Evaporative Duct Impacts,” NPS MS Thesis, March 2001, 136 pp.

Eckardt, Marc C., “Assessing the Effects of Model Error on Radar Inferred Evaporative Ducts,” NPS MS Thesis, March 2002, 170 pp.

KEYWORDS:  Meteorological Measurement, Marine Atmosphere Boundary Layer

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

 

SCALING NEAR-SURFACE ATMOSPHERIC AND SURFACE WAVE INFLUENCES ON RADAR PROPAGATION OVER THE SEA

(RED Experiment Analyses)

K. L. Davidson, Professor of Meteorology

Sponsor: Office of Naval Research, Code 322MM

 

OBJECTIVE: Improve models for describing near horizon Rf/EO propagation over the ocean throughevaluation of the Monin-Obukhov surface-layer scaling for near surface turbulence and refractivity gradients over ocean waves and surface roughness parameterizations.

SUMMARY: Analyses and interpretations were performed on measurements of near-surface refractive gradients, turbulent intensity, and surface wave data obtained during NPS flux buoy deployments from coordinated propagation experiments. These data were from combined collections of in situ meteorological and radar-frequency propagation data conducted off Wallops Island, VA during the springs (March through May) of 1998 and 2000.  The EO data were from combined collections of in situ and propagation  (EO) in San Diego Bay, CA and Duck NC from 1996 through 1998.  Buoy data and EM and EO propagation data were also obtained during the RED experiment conducted in the late summer of 2001.  Collaborative analyses/interpretations during preceding field experiment years emphasized mean airflow properties.  Our own interpretations addressed the use of current bulk methods for estimating optical turbulence (Cn2) and scaling parameters (T*, q*, and u*).  Waves influences have been addressed to qualitatively identify the influence. Existing results demonstrate that current models perform well in unstable conditions but clearly not in stable conditions.

REPORTS/PAPERS:

Mahrt, L., D. Vickers, J. Sun, T. Crawford, G. Crescenti, and P. Frederickson, “Surface Stress in Offshore Flow and Quasi-frictional Decoupling,” Journal of Geophysical Research (Atmospheres), Vol. 106, pp. 20629-20639, 2001.

Jensen, D. R., S. G. Gathman, C. R. Zeisse, C. P. McGrath, G. de Leeuw, H. M. Smith, P. A. Frederickson, and K. L. Davidson, “Electrooptical Propagation Assessment in Coastal Environments (EOPACE) Summary and Accomplishments,” Optical Engineering, Vol. 40, pp. 1486-1498, 2001.

Frederickson, P. A., and K. L. Davidson, “Observational Buoy Studies of Coastal Air-Sea Fluxes,” Journal of Climate, submitted 2001, accepted January 2002.

Zeisse, C. R., A. E. Barrios, S. M. Doss-Hammel, G. de Leeuw, M. Moerman, A. N. de Jong, P. A. Frederickson, and K. L. Davidson, “Low Altitude Infared Propagation Over the Ocean,” Applied Optics, submitted 2001.

PRESENTATIONS:

Davidson, K. L., and P. A. Frederickson, “Influence of Ocean Waves on Near-surface Turbulence & Refraction Profiles: Scaling over Waves,” Abstracts of the National Radio Science Meeting (URSI), Boulder, Colorado, 10-13 January 2001.

Davidson, K. L., and P. A. Frederickson, “Mid-Path Near-Surface Atmospheric Properties in the Roughness and Evaporation Duct (RED) Experiment,” National Radio Science Meeting (URSI), Boulder, Colorado, 7-10 January 2002.

Guest, P. S., K. L. Davidson, P. A. Frederickson, and D. L. Mabey, “Using Instrumented Kites to Quantify Atmospheric Conditions During the RED Experiment,” National Radio Science Meeting (URSI), Boulder, Colorado, 7-10 January 2002.

Davidson, K. L., and P. A. Frederickson, “Near-Surface Meteorology Descriptions and Radar Propagation,” South Dakota School of Mines and Technology, 31 January 2002.

Davidson, K. L., P. A. Frederickson, and D. L. Mabey, “Mid-Path Near-Surface Atmospheric Properties in the Roughness and Evaporation Duct (RED) Experiment,” RED Experiment Data Workshop, San Diego, California, 5-6 February 2002.

Frederickson, P. A., and K. L. Davidson, “Observational (buoy-based) Studies of the Wave Influence on Air-Sea Fluxes,” WCRP/SCOR Workshop on Intercomparison and Validation of Ocean-Atmosphere Flux Fields, Potomac, Maryland, 21-24 May 2001.  [WMO Technical Document No. 1083, pp. 329-332, August 2001]

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Optical Transmission, Rf Transmission, EM/EO Propagation

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

 

SCALING NEAR-SURFACE ATMOSPHERIC AND SURFACE WAVE INFLUENCES ON RADAR PROPAGATION OVER THE SEA

(RED Experiment Analyses)

K. L. Davidson, Professor of Meteorology

Sponsor: Office of Naval Research, Code 322MM

 

OBJECTIVE: Improve models for describing near horizon Rf/EO propagation over the ocean throughevaluation of the Monin-Obukhov surface-layer scaling for near surface turbulence and refractivity gradients over ocean waves and surface roughness parameterizations.

SUMMARY: Analyses and interpretations were performed on measurements of near-surface refractive gradients, turbulent intensity, and surface wave data obtained during NPS flux buoy deployments from coordinated propagation experiments. These data were from combined collections of in situ meteorological and radar-frequency propagation data conducted off Wallops Island, VA during the springs (March through May) of 1998 and 2000.  The EO data were from combined collections of in situ and propagation  (EO) in San Diego Bay, CA and Duck NC from 1996 through 1998.  Buoy data and EM and EO propagation data were also obtained during the RED experiment conducted in the late summer of 2001.  Collaborative analyses/interpretations during preceding field experiment years emphasized mean airflow properties.  Our own interpretations addressed the use of current bulk methods for estimating optical turbulence (Cn2) and scaling parameters (T*, q*, and u*).  Waves influences have been addressed to qualitatively identify the influence. Existing results demonstrate that current models perform well in unstable conditions but clearly not in stable conditions.

REPORTS/PAPERS:

Mahrt, L., D. Vickers, J. Sun, T. Crawford, G. Crescenti, and P. Frederickson, “Surface Stress in Offshore Flow and Quasi-frictional Decoupling,” Journal of Geophysical Research (Atmospheres), Vol. 106, pp. 20629-20639, 2001.

Jensen, D. R., S. G. Gathman, C. R. Zeisse, C. P. McGrath, G. de Leeuw, H. M. Smith, P. A. Frederickson, and K. L. Davidson, “Electrooptical Propagation Assessment in Coastal Environments (EOPACE) Summary and Accomplishments,” Optical Engineering, Vol. 40, pp. 1486-1498, 2001.

Frederickson, P. A., and K. L. Davidson, “Observational Buoy Studies of Coastal Air-Sea Fluxes,” Journal of Climate, submitted 2001, accepted January 2002.

Zeisse, C. R., A. E. Barrios, S. M. Doss-Hammel, G. de Leeuw, M. Moerman, A. N. de Jong, P. A. Frederickson, and K. L. Davidson, “Low Altitude Infared Propagation Over the Ocean,” Applied Optics, submitted 2001.

PRESENTATIONS:

Davidson, K. L., and P. A. Frederickson, “Influence of Ocean Waves on Near-surface Turbulence & Refraction Profiles: Scaling over Waves,” Abstracts of the National Radio Science Meeting (URSI), Boulder, Colorado, 10-13 January 2001.

Davidson, K. L., and P. A. Frederickson, “Mid-Path Near-Surface Atmospheric Properties in the Roughness and Evaporation Duct (RED) Experiment,” National Radio Science Meeting (URSI), Boulder, Colorado, 7-10 January 2002.

Guest, P. S., K. L. Davidson, P. A. Frederickson, and D. L. Mabey, “Using Instrumented Kites to Quantify Atmospheric Conditions During the RED Experiment,” National Radio Science Meeting (URSI), Boulder, Colorado, 7-10 January 2002.

Davidson, K. L., and P. A. Frederickson, “Near-Surface Meteorology Descriptions and Radar Propagation,” South Dakota School of Mines and Technology, 31 January 2002.

Davidson, K. L., P. A. Frederickson, and D. L. Mabey, “Mid-Path Near-Surface Atmospheric Properties in the Roughness and Evaporation Duct (RED) Experiment,” RED Experiment Data Workshop, San Diego, California, 5-6 February 2002.

Frederickson, P. A., and K. L. Davidson, “Observational (buoy-based) Studies of the Wave Influence on Air-Sea Fluxes,” WCRP/SCOR Workshop on Intercomparison and Validation of Ocean-Atmosphere Flux Fields, Potomac, Maryland, 21-24 May 2001.  [WMO Technical Document No. 1083, pp. 329-332, August 2001]

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Optical Transmission, Rf Transmission, EM/EO Propagation

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

 

REFRACTIVITY PROFILE COLLECTION DURING RED  

K. L. Davidson, Professor of Meteorology

Sponsor: Naval Research Laboratory, Tactical Electronics Warfare Division >Washington DC

 

OBJECTIVE: Characterize the low altitude refractivity conditions (particularly the height and strength of possible surface based ducts) that affect RF propagation along the FLIP-based Rf and EO propagation paths during the  Roughness and Evaporation Duct experiment.

SUMMARY: Naval Postgraduate School (NPS) obtained launched rawinsondes and kite-borne sonde profiles from a small boat during the RED experiment conducted on the windward shore of Oahu in August-September 2001.The profiles were obtained during this experiment to provide information for interpreting radio frequency (RF) propagation measurements along a 26 km path between the R/V FLIP, moored 10 km off the north shore of Oahu, and a shore receiver station on Mokapu Peninsula and optical propagation masurements obtained along a 10 km path between FLIP and the north shore of Oahu. The NPS measurement platform was the small vessel Wailoa.  NPS obtained 190 individual near-surface (up to ~100 meters) kite-borne sonde profiles and 20 upper-air balloon-sonde profiles on eight different days during the experiment. Mean meteorological data were also obtained by Scripps-UCSD on the Wailoa during these eight days.

REPORTS/PAPERS:

PRESENTATIONS:

Guest, P. S., K. L. Davidson, P. A. Frederickson, and D. L. Mabey, “Using Instrumented Kites to Quantify Atmospheric Conditions During the RED Experiment,” National Radio Science Meeting (URSI), Boulder, Colorado, 7-10 January 2002.

THESIS DIRECTED:

Mabey, Debra , “Variability of Refractivity in the Surface Layer over the Sea,” NPS MS Thesis, March 2002 (in progress).

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Optical Transmission, Rf Transmission.

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

  

ATMOSPHERIC CORRECTIONS FOR GEODETIC QUALITY RADIO RANGING USING REAL DATA

Kenneth L Davidson, Professor of Meteorology

James R. Clynch, Research Professor of Oceanography

Sponsor: NPS Center for Reconnaissance Research

                 

OBJECTIVE: Assess the role of atmospheric conditions, application of models and measurement capabilities in estimating tropospheric factors in global reconnaissance system performances.

SUMMARY:  The primary goal was to establish limits on the noise (uncertainty) in radio frequency measurements that transit the atmosphere under the influence of  temporal and spatial variations of the neutral atmosphere in space and time. The limitations at very low elevation angles for high altitude and space observation platforms were evaluated and quantified.  Only the troposphere was considered, not the ionosphere.  The results are applicable from about 500 MHz to 100 GHz.   Atmospheric profile data from 6 world wide locations were obtained in the form of balloon data.  Two weeks of data were examined from Oakland, Vandenberg, San Diego, Sweden, Singapore and the Persian Gulf.  Spatial variations were studied using the US west coast sites.  Ray tracing was used to examine the total delay and the bending for radio signals.

 The primary quantity studied was the variation at each site. The natural variability will limit the utility of any model not driven with near real time data.  At elevations below 2 degrees the effect were found to be significant.  The variations were found up to 6 m in delay and 4 milliradians in bending below 0.6 deg.  At 2 degrees the variations were 1.2 m and 0.8 mrad.  Using data up to 600 km away (within the same air mass) reduced the variations above 1 degree by about 90 percent. 

DOD Key Technology Areas:   Sensors

Keywords:  Propagation,  Refraction 

 

DETECTION OF LPI RADAR SIGNALS

D. C. Schleher

Department of Electrical and Computer Engineering/

Information Warfare Academic Group

Sponsor:  National Reconnaissance Office

 

OBJECTIVE:  To design and synthesize an ELINT receiver capable of detecting LPI radar signals with the same sensitivity as available on equivalent conventional pulsed signals.  To accomplish this detection in the presence of a large number of  interfering conventional pulsed radars and to measure the radar's mode, allowing the operating range of the LPI radar to be determined.

SUMMARY:  An adaptive LPI Radar Detector was previously synthesized and successfully simulated.  As determined by stimulation, it provided an operationally significant range of 60 km on a known LPI radar signal.  In addition, it determined the LPI radar's mode.  A temporal mask approach was used to allow detection  of the LPI radar signal in the presence of over 500 Furuno radars with random modes.   An experimental-mental demonstration was successfully conducted that confirmed the theoretical design.  The experiment used a threat simulator that radiated synthesized LPI radar signals.  The LPI signals were intercepted by a Low Noise Receiver and A/D converted using a 250 MHz Gage Digital Sampling Oscilloscope.  The signal was than processed in a digital signal processor using MATLAB code.  LPI signals at a level of -100 dBm were detected and the radar's mode determined.

THESIS DIRECTED:  Teng, H. and Ong, P., "Digital LPI Radar Detector," Masters Thesis, Naval Postgraduate School, March 2001.

DOD KEY TECHNOLOGY AREA:  Surveillance

KEYWORDS:  SIGINT, LPI Radar, Digital Pulse Compression 

 

POSITIONAL ACCURACY OF TDOA MISSILE SYSTEM

D. C. Schleher

Department of Electrical and Computer Engineering/

Information Warfare Academic Group

Sponsor:  Naval Air Warfare Center/Weapon Division

 

 

OBJECTIVE:  To analyze and synthesize an FDOA/TDOA system capable of providing a 1 m rms position accuracy from telemetry signals radiated from a test missile during flight test.  Also, to investigate the accuracy of a Time, Space and Position Information (TSPII) system developed by NAWC - Weapons Division - China Lake.

SUMMARY:  A lower bound on the accuracy achievable using a mine base station configuration, employed at White Sands Missile Range, as a function of signal-to-noise ratio was determined.  The simulation used a missile trajectory determined from measured laser tracker data.  The methodology used in the simulation was to determine FDOA from each base station with respect to the reference station and then to use this to determine the TDOA of the missile.  This was used in the Smith-Able algorithm to determine the position of the missile.  A signal-to-noise ratio of 40 dB was required to achieve a one meter rms positional accuracy of the missile's location.  The TSPI system was found to be limited by the susceptibility of the zero crossing counter to noise and fading and the use of a wideband telemetry signal source in the missile.  A system using a stable source in the missile modulated by a pseudo noise code was synthesized.  This is currently under investigation using modeling and simulation techniques.  An experimental test of this system is planned.

THESIS DIRECTED: 

Klaszky, R., "Analysis of the Positional Accuracy of a Range Difference Missile Position Measuring System," Master's Thesis, Naval Postgraduate School, September 2000.

Heng, C., "Kalman Filtering of FDOA/TDOA Missile Tracking System," Master's Thesis, Naval Postgraduate School, March 2001.

DOD KEY TECHNOLOGY AREA:  Modeling and Simulation

KEYWORDS:  TDOA, FDOA, Missile Location, TSPI

 

RADAR REMOTE SENSING

Jeffrey B. Knorr, Professor

Department of Electrical and Computer Engineering

and

Bob Bluth, Director

Center for Remotely Piloted Aircraft Studies

Sponsor: ONR

 

 OBJECTIVE:  The objective of project is to acquire and modify two military radars for meteorological research.

SUMMARY:  An Army AN/MPQ-64 Sentinal radar was acquired in the Spring of 1999 and was brought  to operational status during the Fall of 1999 and the Winter of 2000.  An SBIR project, N01-035, Weather Processor for Rapid Scanning Tactical Radars,was initiated with ProSensing, Amherst, MA to add a Doppler processor to the radar for severe storm research.  During May 2001, a meeting was held with ProSensing engineers to discuss details associated with the addition of the weather processor.  It is expected that initial testing of the processor will take place during 2002. 

During 2000 steps were also taken to obtain an Army AN/TPQ-37 Firefinder radar.  A radar was delivered in the Spring of 2001 but  the Army subsequently requested that the radar be returned  to satisfy another requirement and it was relinquished in the Fall of 2001.   The AN/TPQ-37 radar is similar to the AN/SPY-1 radar installed on the Navy’s Aegis cruisers and destroyers.  A project was planned to add a weather processor to this radar so it could be used as a testbed for investigation of AN/SPY-1 algorithms to extract meteorological data.  This goal must now await the acquisition of another AN/TPQ-37 radar.

The overall long term objective of this project is to develop radar remote sensing capabilities that will provide meteorological data that can be used to describe weather phenomena, particularly in support of air operations in the fleet battlespace.

PUBLICATIONS:

None

PRESENTATIONS:

J. B. Knorr, R. Bluth and A Pazmany, “Rapid Scan 3D Volumetric Weather Radar,” 30th International Conference on Radar Meteorology, Munich, Germany, 14-19 July 2001

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors.

KEYWORDS: Remote sensing, radar meteorology.

 

RESEARCH SUMMARIES

2000

 

AN OPTIMUM SENSOR NETWORK CONFIGURATION

Phillip E. Pace, Associate Professor

Department of Electrical and Computer Engineering

Sponsor: NAVAIR and Johns Hopkins University

 

OBJECTIVE: This project provides support to the Airborne Electronic Attack (AEA) Analysis of Alternatives (AoA) Modeling & Simulation effort in the area of sensitivity analysis of the solutions evolved by NRL’s Airborne Reactive Electronic Warfare Simulation (ARES). This network-centric analysis is to determine the robustness in the derived measures of effectiveness or sensitivity to system failures or variances in performance parameters. In addition, a sensitivity analysis is performed to test the vulnerability of solutions to the environment (e.g., threat intensity, terrain, IADS, etc).

SUMMARY: This work continues the investigation of using the ARES to determine an optimum sensor/jammer network configuration for the suppression of enemy air defense (SEAD) using the classified RT4, RT2 scenarios. This involves evaluating the sensitivity of the Measures of Effectiveness (MOEs) to small perturbations in the optimal solution (as derived by the genetic algorithm in ARES). For example, a trade space for RT4, RT2 might involve four EA-6Bs, two Global Hawk unmanned aerial vehicles (UAVs), and six Miniature Air Launched Jammers (MALJs). After the ARES genetic simulation, the optimum answer could be: three EA-6Bs with ICAP 3 receivers but with an increase in sensitivity (e.g., by 10 dB), two Global Hawks with receivers having –90 dBm sensitivity and a MALJ with a specific X-band jammer onboard. The derived measures of effectiveness (MOE) might be for example: total tracking time by early warning radars=20 s and total Surface-to-Air Missile (SAM) engagements=20. A perturbation of the solution (e.g., no Global Hawk UAVs) is prepared and several vignettes are run for both RT2, RT4 to investigate the effect on the MOEs. This in turn will demonstrate the robustness of the MOEs to perturbations from the optimal solution. The tasks involved with this effort include running the RT4, RT2 distributed scenarios with conventional ARES (no genetic algorithms) to verify solutions and corresponding MOEs and then changing one or more parameters in the scenario solution and rerunning ARES to investigate the sensitivity of the derived MOEs to these changes.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, and Electronics

KEYWORDS: Network-centric, Analysis of alternatives, Airborne electronic attack, EA-6B, Unmanned aerial vehicles, Suppression of enemy air defense

 

 

NAVY SURFACE ANTI-SHIP CRUISE MISSILE THREAT SIMULATOR VALIDATION WORKING GROUP

Phillip E. Pace, Associate Professor

Department of Electrical and Computer Engineering

Sponsor: Naval Research Laboratory, Washington DC

 

OBJECTIVE: The objective of this proposal is to provide technical leadership to the Navy Surface Anti-Ship Cruise Missile Threat Simulator Validation Working Group. Three types of simulations are currently being validated by the SVWG for use in test and evaluation. These include (a) radio frequency missile hardware simulators, (b) infrared missile hardware simulators and (c) computer models of missile seekers and related electronics.

SUMMARY: To insure that each ASCM simulator accurately represents the associated threat missile, OPNAV (N912) established the Navy-Unique ASCM Simulator Validation Working Group (SVWG). Three types of simulations are currently being addressed by the SVWG for use in EW test and evaluation (OPEVAL). These include (a) radio frequency hardware simulators, (b) infrared hardware simulators and (c) computer models. The duties for the SVWG chairman include coordinating with the Navy’s Simulator Validation Coordinator, the NRL ENEWS Program Manager and other Navy commands (e.g., Commander Operational Test and Evaluation Force) to prioritize the simulator validations for N912 approval.  Additional responsibilities include coordinating with the Office of Naval Intelligence for threat data review and convening the SVWG as an independent and unbiased reviewer for all of the validation reports.

PUBLICATIONS:

Pace, P. E., Nash, M. D., Zulaica, D. P., Di Mattesa, A. A., and Hosmer, A., “A Relative Targeting Architecture for Captive-Carry Missile Simulator Experiments,” IEEE Transactions on Aerospace and Electronic Systems, to be published.

P. E. Pace and D. P. Zulaica, “A relative targeting architecture for test range visualization in captive-carry missile simulator experiments: USS Peterson-Nulka Test Results (July 9, 1998), Naval Postgraduate School Technical Report, NPS-EC-00-006, May 3, 2000.

PRESENTATIONS:

P. E. Pace, “SVWG Organizational Chart and Validation Plan,” Presented at the N9 Threat ASCM Simulator Validation Working Group,” Naval Research Laboratory, Feb. 1, 2000.

P. E. Pace, “The SVWG Charter – A Proposal,” Presented at the N9 Threat ASCM Simulator Validation Working Group,” Naval Research Laboratory, Feb. 1, 2000.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, and Electronics

KEYWORDS: Hardware-in-the-loop, Threat missile simulators, Infrared, Computer missile simulation

 

 

DIGITAL TARGET IMAGING ARCHITECTURES

Phillip E. Pace, Associate Professor

Douglas J. Fouts, Associate Professor

Department of Electrical and Computer Engineering

Sponsor: Office of Naval Research, Washington DC

 

OBJECTIVE:The technical objective of this research is twofold. The first objective is to quantify the system-level implementation tradeoffs of a digital, programmable imaging architecture to generate realistic false target signatures against high resolution imaging radars, including synthetic aperture radar (SAR) and inverse SAR (ISAR), using all-digital techniques and modern digital radio frequency memory (DRFM) technology. The second objective is to design, fabricate and test an all digital target imaging device capable of generating large false targets using wideband chirp signals of any duration to provide a new, superior radio frequency (RF) decoy capability.

SUMMARY: To generate the target and its motion, the user will program the target extent, the amplitude characteristics and the motion profile of each scatterer within the image on a pulse-to-pulse basis. The imaging device will reduce both the noise of the repeated signal and the size of such a system over prior analog technology with a significant cost reduction. The all-digital design will permit real-time alteration of operating parameters, permitting rapid and adaptive shifting among different types of large targets. It is expected that the device will be transitioned into the AN/SLY-2 (AIEWS) Increment-2 in order to generate structured false targets including any target motion or movement required for time-critical platform protection. In this first year we investigate the system-level tradeoffs and design a new programmable imaging architecture able to generate high-fidelity target images that have a realistic size (e.g., 512 range bins).

PUBLICATIONS:

P. E. Pace, S. Ekestorm, C. Karow and D. Fouts, “An all-digital image synthesizer for countering high-resolution imaging radars,” Naval Postgraduate School Technical Report, NPS-EC-00-005, Feb. 24, 2000.

P. E. Pace, D. J. Fouts, S. Ekestorm and C. Karow, “Digital image synthesizers for countering high-resolution imaging radar,” IEEE Transactions on Aerospace and Electronic Systems, (in review).

PRESENTATIONS:

P. E. Pace, P. E., Ekestorm, S., Karow, C., Fouts, D., “All-Digital Image Synthesizer for Countering High Resolution Imaging Radars - Progress Report FY99/00,” Presented at the TTCP-Technical Program 3, Naval Research Laboratory, Washington D.C., Jan. 12, 2000.

P. E. Pace, P. E., Ekestorm, S., Karow, C., Fouts, D., “All-Digital Image Synthesizer for Countering High Resolution Imaging Radars - Progress Report FY99/00,” Presented at Code 5740 - Ships Self-Defense, Naval Research Laboratory, Washington D.C., Jan. 13, 2000.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, and Electronics

KEYWORDS: Imaging decoys, inverse synthetic aperture radar, counter-targeting, counter-terminal, digital radio frequency memories, DRFM

 

 

 

ROBUST SYMMETRICAL NUMBER SYSTEMS

Phillip E. Pace, Associate Professor

David C. Jenn, Associate Professor

Department of Electrical and Computer Engineering

Sponsor: Naval Postgraduate School

 

OBJECTIVE:  The objective of this research is to investigate new symmetrical number systems and their application to electronic engineering systems.

SUMMARY: Both an optimum symmetrical number system (OSNS) and a robust symmetrical number system (RSNS) have been investigated. The RSNS has an inherent performance advantage over the OSNS design since the encoding errors due to several comparators changing at one time is eliminated (Gray code properties). Applications investigated include high-speed folding analog-to-digital converters (ADCs) and phase-sampled direction finding antenna architectures.  Symmetrical number system preprocessing is used to decompose the amplitude analyzing (folding ADC) or spatial filtering (DF antenna) operation into a number of parallel sub-operations (moduli) that are of smaller computational complexity. A much higher resolution is provided after the N different moduli are used and the results of thee low precision sub-operations are recombined. By incorporating the OSNS or RSNS preprocessing concept, the performance of the system can be analyzed exactly. The OSNS gives the maximum dynamic range while the RSNS reduces considerably, the number of possible encoding errors. Simulation results for an RSNS ADC are reported as well as experimental results for a prototype OSNS and RSNS direction finding system.

PUBLICATIONS:

Pace, P.E., Styer, D., and Akin, I.A., “A Folding ADC preprocessing architecture employing a robust symmetrical number system with Gray-code properties,IEEE Transactions on Circuits and Systems--II:Analog and Digital Signal Processing, Vol. 47, No. 5, pp. 462--467, May 2000.

Pace, P.E., Styer, D., and Ringer, W.D., “An optimum SNS-to-binary conversion algorithm and pipelined field programmable logic design,” IEEE Transactions on Circuits and Systems—II: Analog and Digital Processing, Vol. 47, No. 8, pp. 736--745, Aug. 2000.

Pace, P. E., Wikersham, D., Jenn, D., York, N., “High-resolution phase sampled interferometry using symmetrical number systems,” IEEE Transactions on Antennas and Propagation, to be published.

PRESENTATIONS:

Wickersham, D. J., Pace, P. E., Styer, D., Jenn, D. C., Vitale, R., and York, N.S., “High-resolution DF architectures using a robust symmetrical number system encoding,” Proceedings of the IEEE International Conference on Phased Array Systems and Technology, Dana Point, CA pp. 169-172, May 22, 2000.

PATENTS:

Pace, P. E., Styer, D., “Wideband undersampling digital receiver, Naval Postgraduate School, US Patent 6,031,879, Feb. 29, 2000.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, and Electronics

KEYWORDS: Symmetrical number system, Direction finding antennas, Folding analog-to-digital converter, Gray code property

 

PHOTONIC SAMPLING ARCHITECTURES

FOR MICROWAVE SIGNAL COLLECTION AND ANALYSIS

Phillip E. Pace, Associate Professor

John P. Powers, Professor

Department of Electrical and Computer Engineering

Sponsor: DARPA and Naval Postgraduate School

 

 

OBJECTIVE: The objective of this research is the experimental investigation of a photonic sigma-delta architecture for high-speed sampling and digitization of RF and microwave signals. Our photonic sigma-delta ADC uses a mode-locked laser to oversample an input signal at two Mach-Zehnder interferometers. A fiber lattice accumulator is embedded within a feedback loop around a single-bit quantizer to spectrally shape the quantization noise to fall outside the signal band of interest.  Decimation filtering is applied to the quantizer output to construct the input signal with high resolution. 

SUMMARY: A single-bit, first-order, electro-optical sigma-delta modulator for use in wideband digital antennas was designed, constructed and experimentally tested. The construction and experimentation of the modulator was in two parts: the signal oversampling subsystem and the fiber lattice accumulator.  A pulsed 1550-nm laser diode source was used to optically sample the RF antenna waveform. Performance characteristics of this subsystem were compared with the results of a computer simulation. A comparator circuit was designed and constructed in order to drive the signal accumulation in the fiber lattice in the proper direction. Before constructing the fiber lattice, the phase modulator and the semiconductor optical amplifier were characterized. The results of the characterization of the phase modulator determined the appropriate output voltage required by the comparator circuit. The characterization test of the optical amplifier established the correct operating range required for a monotonic linear response of the fiber lattice accumulator. Finally, a 4-port fiber lattice accumulator was constructed using a phase modulator, a semi-conductor optical amplifier, a pair of variable-ratio directional couplers and a delay loop equal to the pulse repetition interval of the sampling laser. The directional coupler coupling coefficients were matched with the gain of the optical amplifier to produce a monotonic response of the fiber lattice accumulator. Experimental results for the sigma-delta architecture were taken. Correct accumulation in the fiber lattice was not achieved since the linewidth of the laser diode was too broad. In addition, the need for a piezo-electric transducer for adaptively adjusting the optical cavity length was identified.

PUBLICATIONS:

Pace, P.E., Bewley, S.A., and Powers, J.D., “Fiber lattice accumulator design considerations for optical Sigma-Delta analog-to-digital converters,” Optical Engineering, Vol. 39, No. 6, pp. 1517–1526, June 2000.

CONFERENCE PRESENTATION:

W. U. Gillespie, J. P. Powers, P. E. Pace, “Design and experimental evaluation of an integrated optical sigma-delta modulator for wideband digital antennas,” Presented at the DARPA/MTO 2000 RF Lightwave Integrated Circuits, Cincinnati OH, 16 Oct. 2000.

DOD KEY TECHNOLOGY AREAS: Photonics, Electronics, Sensors

KEYWORDS: Sensors, Sigma-delta, Sampling, Electro-optic

 

 

NULKA FOT&E TEST PLAN DEVELOPMENT AND TECHNICAL SUPPORT

Phillip E. Pace, Associate Professor

Kenneth Davidson, Professor

Department of Electrical and Computer Engineering

Sponsor: Command Operational Test and Evaluation Force

 

OBJECTIVE: In order to evaluate the EW effectiveness of the Nulka/MK53 decoy launch system, Follow-On Test and Evaluation (FOT&E) exercises at sea must be conducted using captive-carry seekers, and test ships conducting both live NULKA firings as well as hovering the NULKA rocket with the use of a helicopter. Command Operational Test and Evaluation Force (COMOPTEVFOR) is the Navy’s independent test agent responsible for developing the test requirements and test procedures. They also perform the analysis of the field test data to determine the degree of the NULKA’s effectiveness. This technical support contract enabled consultation with COMOPTEVFOR to aid in the design of the test requirements and procedures as well as guide the decision for the necessary tools needed for the post-test analysis

SUMMARY: Through several meetings at COMOPTEVFOR, the group was able to lay down a specific test plan that exercised the NULKA’s EW capability. The test involved multiple ships at sea, several NULKA rounds for live fire, several captive-carry threat seekers (NRL’s P-3) and plans for a helicopter to hover the rocket at various positions.

DoD KEY TECHNOLOGY AREA: Electronic Warfare, Sensors, and Electronics

 

MAGNETIC FIELD SENSORPLACEMENT

Michael A. Morgan, Professor

Department of Mathematics

Department of Electrical and Computer Engineering

Sponsor:  Office of Naval Research

 

OBJECTIVE:  The major technical objective of this research is to investigate robust techniques for predicting spatial B-field signatures of elongated magnetic objects using vector field measurements near to the object.   Of significant importance is development of a procedure for predicting the number and optimal placement of the field sensors to attain a desired accuracy level in the presence of noise and other measurement errors.

SUMMARY: Fiscal Year 2000 progress involved:  (1) development of the field generation program for the dipole enclosed in a hollow prolate spheroidal shell, and (2) initial evaluation of the least-squares field prediction algorithm for single mode test fields.    Work during this first year's effort has involved only the m=0 axisymmetric field mode set. 

CONFERENCE PRESENTATIONS:

M.A. Morgan, "Near-Field Imaging Using Cylindrical Harmonic Back-Propagation," PIERS 2000, Cambridge, MA, July 10, 2000.
M.A. Morgan, "Null Spaces in Equivalent Current Field Generation," PIERS 2000, Cambridge, MA, July 10, 2000.
 

THESIS DIRECTED:

Yopp, Stacey, “Magnetic Field Sensor Placement,” Master’s Thesis, June 2001.

DOD KEY TECHNOLOGY AREAS: Sensors, Modeling and Simulation

KEYWORDS: Near-Fields, Magnetic Field Imaging

 

IMPULSE ANTENNA MODELING

Michael A. Morgan, Professor

Department of Mathematics

Department of Electrical and Computer Engineering

Sponsor: Naval Surface Warfare Center

 

OBJECTIVE: The goal of this task is to investigate the impulse radiation characteristics of specified antennas in the presence of buildings over real earth

SUMMARY: Wire-grid numerical modeling of antenna and building structures has been completed using frequency-stepped calculations using GNEC.   Impulsive near-fields within the modeled building is found using time-domain source modeling and inverse FFT convolution.   Animations of fields within the structure are created using custom MatLab programs.

DOD KEY TECHNOLOGY AREA: Modeling and Simulation

KEYWORDS: Impulse response, antenna modeling, near-fields, GNEC

 

WIDEBAND LOW-PROFILE COMMUNICATION ANTENNA DESIGN
Michael A. Morgan, Professor

Department of Mathematics

Department of Electrical and Computer Engineering
Sponsor: Army Research Office

 

OBJECTIVE: A finite element algorithm was developed for use in designing omnidirectional wideband VHF communication antennas having low-drag blister type profiles for use on helicopters.

SUMMARY:    An analysis tool has been created for use in the design of efficient wideband VHF omnidirectional antennas for employment on Army helicopters.    Dielectric loading can be used to optimize  impedance  matching  and antenna pattern over a desired range of frequency.    Tapered feed and flare sections, without dielectric loading, provide impedance matching over ultra-wide bandwidths.    The finite-element solution uses the coupled-azimuthal potential field  formulation with mesh termination by the field-feedback technique.    This software tool allows designers to optimize performance while constraining the antenna’s physical profile through use of inhomogeneous lossy dielectric loading.         

DOD KEY TECHNOLOGY AREAS: Sensors, Modeling and Simulation

KEYWORDS: Wideband, Finite Elements, Antenna Design

 

JAMMING TACTICS AND EMPLOYMENT OF UEU

AGAINST ADVANCED RADAR AND COMMUNICATIONS SYSTEMS

D. C. Schleher

Department of Information  Science and

Electrical & Computer Engineering

Sponsor:  Navy Information Warfare Activity

 

 

OBJECTIVE: Develop UEU employment tactics and advanced jamming techniques to counter communications, data links and advanced J-Band threats.

SUMMARY:   A number of advanced threats susceptible to the new UEU jammer capability available in the EA-6B were identified.  These include advanced radars using pulse compression and pulsed Doppler type waveforms.  Communications jamming is accomplished using the UEU to generate stable narrow band frequency spots with minimum spurious components that prevent interference with friendly communications systems.  Data links can be jammed using pulse patterns generated by the UEU.  Further research will identify specific waveforms and tactics to exploit the new capabilities available using the UEU.

DOD KEY TECHNOLOGY AREA:   Electronic Warfare

KEYWORDS:  EW, Communications Jamming              

 

EVALUATION OF  TDROP FOR USE IN THE MARINE ATMOSPHERIC BOUNDARY LAYER

K. L. Davidson, Professor of Meteorology

Sponsor:  Space and Naval Warfare Command, SPAWAR PMW 185

 

OBJECTIVE: Validate/verify the Tactical Drop-sondes (TDrop) to meet requirements for accurate and tactically significant measurements of temperature, moisture, and pressure within the lower marine atmosphere.

SUMMARY: Evaluation testing was performed to validate that the performance of the installed TDrop sensor suite was comparable to off-the-shelf atmospheric sondes  currently available to DoD.  Specifically, the accuracy and resolution of the TDrop sensors for measuring atmospheric pressure, temperature and relative humidity were evaluated. The procedures for TDrop testing were carried out in three phases:

Phase I: Static instrument chamber tests conducted at the National Institute of Standards and Technology (NIST) during the week of 11 September 2000.

Phase II: Dynamic sensor verification/comparison tests conducted at Wallops Island, VA, during the week of 2 October 2000.

Phase III:  Airborne/Atmospheric Characterization tests conducted in Monterey Bay, CA, during the week of 16 October 2000.

 

REPORTS/PUBLICATIONS:

Davidson, K. L., “TDrop Test Plan for Laboratory Static Calibration Test (NIST)”, September 2000.

Frederickson, P. A. and K. L. Davidson, “Test Plan for Wallops Island Dynamic Comparison Test,” October 2000.

Davidson, K.L,. "TDrop Test Plan for Test Ship and Test Aircraft Monterey Bay", October, 2000.

Davidson, K.L. and Douglas Ranard, “NIST Instrument Chamber Static Test Results: BAE-TDrop,” NPS Technical Report, NPS-MR-01-001, November 2000.

Frederickson, P. A. and K. L. Davidson, “Results of the TDrop Dynamic Comparison Test (Phase II),” NPS Technical Report, NPS-MR-01-002, November 2000.

Guest, P. S., K. L. Davidson, and P. A. Frederickson, “Monterey Bay Airborne/Atmosphere Characterization Test Results: BAE-Tdrop (Phase III),” NPS Technical Report, NPS-MR-01-003, November 2000, 47 pp.

Guest, P. S., K. L. Davidson, and P. A. Frederickson: “Analyses of TDrop Performance Parameters from Static and Dynamic Tests,” NPS Technical Report, NPS-MR-01-004, November 2000, 21 pp.

Davidson, Kenneth L., and Ranard, Douglas, “TDrop Static and Dynamic Tests: Final Report on FY00 V&V,” NPS Technical Report, NPS-MR-01-005, November 2000.

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer

DOD KEY TECHNOLOGY AREAS:  Battlespace Environments, Sensors 

 

METOC DATA ACQUISITION (MORIAH)

K. L. Davidson, Professor of Meteorology

SPONSOR: Sponsor:  Space and Naval Warfare Command, SPAWAR PMW 185

 

OBJECTIVE: Support acquisition strategy of a shipboard Meteorology and Oceanography parameter sensor system, MORIAH, by carrying out validation, verification and integration procedures. Prepare software documentation for acquisition and evaporation duct calculation.

SUMMARY: NPS evaluated and documented performance characteristics of MORIAH hardware and Software for use in the complex METOC and electronic environment of a Navy warship operating in the North Atlantic, the Mediterranean and in the Persian Gulf.  These were also done for MORIAH like systems mounted on buoys deployed in coastal regimes in support of propagation tests. The ship data were collected by the JHU/APL  SEAWASP system, a prototype MORIAH system. Examinations of METOC data measurement were of hardware component performance with regard to MORIAH MNS requirements.  Ship and buoy hardware included mounted, and deployed (floatsonde and rocketsonde) sensors. System performance evaluation was of characteristics of both the MORIAH hardware and acquisition and calculation/editing software.  Documentation was performed of algorithms for calculating METOC variables and evaporation duct within the MORIAH  system.

REPORTS/PUBLICATIONS:

Frederickson, P., K. Davidson, and A. K. Goroch, 2000, “Operational Bulk Evaporation Duct Model for MORIAH,” NPS/MR Technical Report, NPS/MR-2000-002, 5 May 2000, 69 pages.

Goroch, A. K., Mary Jordan, Paul Frederickson, and K. L. Davidson, “Standard Meteorological Equations and Algorithms Used in MORIAH Processing,” NRL/NPS report, June 2000, 105pp.

Frederickson, P. A., and K. L. Davidson, “A Sensitivity and Convergence Analysis of a Bulk Air-Sea Flux Model.” Preprints, 14th Symposium on Boundary Layers and Turbulence, Aspen, CO, American Meteorological Society, pp. 298-301, 7-11 August 2000.

THESIS DIRECTED:

KEYWORDS:  Meteorological Measurement, Marine Atmosphere Boundary Layer

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

 

 

OPERATIONAL METOC MEASUREMENT SYSTEMS (METCAST) 

K. L. Davidson, Professor of Meteorology

Sponsor:  Space and Naval Warfare Command, SPAWAR PMW 185

 

 

OBJECTIVE: Provide technical guidance in MORIAH ORD/RFP preparations. Perform special analysis and interpretation on sensor and model requirements. Evaluate merging of technologies for regional EM/EO assessments.

SUMMARY: Techniques demonstrate the capability of automated record keeping, with the potential of electronic transmission and receipt of METOC data at sea. Demonstrated the capability to automate transmission of continuous METOC data to central METOC fleet support / production centers using COTS hardware and software.  Additionally, developed was a prototype computer based application for logging METOC observation data and preparing routine required reports. This represents a substantial advance in METOC record keeping, delivery to a central site, and sharing within the fleet.

THESIS DIRECTED: 

Nisley, William H II, “Automated Meteorological and Oceanographic Data Collection and Distribution in Support of C4I, Weapons, and Remote Sensing Systems,” NPS M.S. Thesis, September 2000, 75 pp.

 

KEYWORDS: Meteorological Measurement, METOC data transfer

DOD KEY TECHNOLOGY AREAS: Battlespace Environments

 

 

BUOY MEASUREMENT OF ATMOSPHERIC SURFACE-LAYER  MEAN AND TURBLULENT/FLUX PARAMETERS AND SURFACE WAVES: SUPPORT OF ICON AND MUSE/AOSN

K. L. Davidson, Professor of Meteorology

Sponsor: Office of Naval Research (Via NPS/OC  PI: J. Paduan)

 

OBJECTIVE: Obtain continuous buoy-based descriptions of airflow mean and turbulent/flux and surface temperature and wave properties during oceanographic ICON and MUSE/AOSN investigations in Monterey Bay.

SUMMARY: NPS personal and equipment provided collection of near-surface and surface environmental measurements from an instrumented buoy in Monterey Bay during two oceanography formulated experiments; ICON and MUSE/AOSN  The NPS ‘Flux’ buoy was deployed off Moss Landing, Ca for two period of approximately 9 weeks each, from the 1st week of September to mid-November 1999 and from mid-January 2000 to mid March 2000 for ICON and for a period of approximately 10 weeks, from the 1st week  of August to the 1st week of November 2000 for MUSE/AOSN.  Both mean and turbulent measurements from the buoy were obtained to describe near-surface forcing of the ocean and buoy motion measurements were made to describe surface wave properties.  Real-time Rf transmission of the some data occurred and edited and analyzed data sets from NPS buoy were provided to NPS and CSUMB oceanography investigators performing  remote sensing of ocean properties (ICON) and modeling  of meso-scale features upper Monterey Bay (MUSE/AOSN).

REPORTS/PAPERS: 

Frederickson, P. A., K. L. Davidson, F. Keith Jones and Tamar Neta, “ FLUX Buoy Data Report, ICON September - November 1999 Deployment in Monterey Bay, CA,” 20 February 2000,  29 pp.

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Surface fluxes, waves

DOD KEY TECHNOLOGY AREAS: Environments, Sensors

 

NEAR-SURFACE SCALAR PROFILES IN WALLOPS’00:FLUX –BUOY MEASURMENTS, ANALYSES, AND PHYSICAL MODELING

K. L. Davidson, Professor of Meteorology

Sponsor: Naval Surface Warfare Center: Dahlgren Division (NSWCDD)

 

 

OBJECTIVE: Obtain near-surface atmospheric and surface data that will enable gradients of the radar/radio wave refractivity and wave conditions to be estimated for interpretation of near-horizon EM propagation.

SUMMARY: NPS personal and equipment were involved in the collection of near-surface and surface environmental measurements from an instrumented buoy in support of the Wallops’00 propagation experiment.  The NPS ‘Flux’ buoy was deployed off Wallops Island, VA, for a period of approximately 6 weeks, from 1 April through mid-May 2000. Both mean and turbulent measurements from the buoy were made to describe near-surface refractivity profiles and buoy motion measurements were made to describe surface wave properties.  Edited and analyzed data sets from NPS buoy were provided  to NSWC-DD persons performing  analyses of Rf propagation conditions during the period.

REPORTS/PAPERS:

Davidson, K. L., P. A. Frederickson, and A. K. Goroch, “Analysis and Validation of an Operational Bulk Surface-Layer (Evaporation Duct) Model,” National Radio Science Meeting (URSI), Boulder, CO, 5-8 January 2000.

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Optical Transmission, Rf Transmission

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

 

 

ATMOSPHERIC  CIMREP (ADVANCED PROPAGATION MODEL)

K. L. Davidson, Professor of Meteorology

Peter Guest, Associate Research Professor of Meteorology

Sponsor: Commander, Naval Meteorology and Oceanography Command (CNMOC)

 

OBJECTIVE:Coordinate and serve as members of a COMNOAVMETOCCOM Independent Model Review and Evaluation Panel (CIMREP) for the Atmosphere.  The model evaluated is the Advanced Propagation Model (APM) submitted for inclusion in Oceanographic and Atmospheric Master Library (OAML).

SUMMARY: Professor Kenneth L. Davidson and Dr. Peter Guest were NPS participants in the CIMREP. Arrangements were made for several propagation model experts to be members of the CIMREP. Members were from NSWC-DD, SSC, PSU, and JHU/APL as well as NPS. The CIMREP for the Advanced Propagation Model (APM), version 1.0, was planned for February-September 2000 time-frame. A “kick off” meeting was held during week of 20 March 2000 at NPS with most members present. A second and final meeting was held at the Pennsylvania State University, State College PA during the week of 2 September, 2000. The CIMREP members reviewed the submitted APM documents and ran the APM code.  APM developers at the SSC-SD, Tropospheric Branch, (Code D883) were interviewed to understand aspects of the model and their testing methodology.  Final report was prepared and submitted to sponsor in February 2001. 

REPORTS/PAPERS:

KEYWORDS:  Rf Transmission, propagation model, Marine Atmosphere Boundary Layer

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors 

 

SCALING NEAR-SURFACE ATMOSPHERE AND WAVE INFLUENCES ON Rf/EO PROPAGATION OVER THE SEA

K. L. Davidson, Professor of Meteorology

Sponsor: Office of Naval Research, Code  322MM

 

OBJECTIVE: Improve models for describing near horizon Rf/EO propagation throughevaluation of the Monin-Obukhov surface-layer scaling for near surface turbulence and refractivity gradients.

SUMMARY: Analyses and interpretations were performed on near-surface refractive gradients, turbulent transport, and surface wave data obtained from buoys during  coordinated experiments. The Rf data were from combined collections of in situ and propagation (Rf ) off Wallops Island, VA during the springs (March through May) of 1998 and 2000. The EO data were from combined collections of in situ and propagation  (EO) in San Diego Bay, CA and Duck NC from 1996 through 1998.  Collaborative analyses/interpretations during preceding field experiment years emphasized mean airflow properties.  Our own interpretations addressed the use of current bulk methods for estimating optical turbulence (Cn2) and scaling parameters (T*, q*, and u*).  Waves influences have been addressed to qualitatively identify the influence. Existing results demonstrate that current models perform well in unstable conditions but clearly not in stable conditions.

REPORTS/PAPERS:

Frederickson, P. A., K. L. Davidson, C. R. Zeisse, and C. S. Bendall, “Estimating the Refractive Index Structure Parameter (Cn2) Over the Ocean Using Bulk Methods.” Journal of Applied Meteorology, vol. 39, pp. 1770-1783, October 2000.

Jensen, D. R., S. G. Gathman, C. R. Zeisse, C. P. McGrath, G. de Leeuw, M. H. Smith, P. A. Frederickson, and K. L. Davidson, “Electro-optical Propagation Assessment in Coastal Environments (EOPACE) Summary and Accomplishments.”  Optical Engineering, accepted for publication, 2001.

Zeisse, C. R., A. E. Barrios, S. M. Doss-Hammel, G. de Leeuw, M. Moerman, A. N. de Jong, P. A. Frederickson, and K. L. Davidson, “Low Altitude Infrared Propagation Over the Ocean.  Applied Optics, accepted for publication, 2001.

PRESENTATIONS:

Frederickson, P. A., and K. L. Davidson, “Air-Sea Flux Measurements From a Buoy in a Coastal Ocean Region.” Preprints, 14th Symposium on Boundary Layers and Turbulence, Aspen, CO, American Meteorological Society, pp. 530-533, 7-11 August 2000.

KEYWORDS: Meteorological Measurement, Marine Atmosphere Boundary Layer, Optical Transmission, Rf Transmission

DOD KEY TECHNOLOGY AREAS: Battlespace Environments, Sensors

This is an official U.S. Navy website.
All information contained herein has been approved for release by the NPS Public Affairs Officer.
Page Last Updated: Aug 15, 2012 12:04:12 PM | Contact the Webmaster