Some Notes from the Lockheed-Martin/Univ. of Illinois Meeting on
Nov. 11, 1998
By Aaron Lanterman
Notes from the Morning Meeting
The morning meeting focused on the experiences of workers at Lockheed-Martin.
- Some researchers at Lockheed-Martin have employed the NEC software
(developed by Lawrence Livermore) for
scattering calculations and the AREPS model (contact: Wayne Paterson,
619-553-1423, www.spawar.navy.mil) for atmospheric propagation
- The L-M system target track update rate is 8 updates per second.
- Useful book: “Bistatic Radar” by Nicholas J. Willis, available from
Technology Service Corp., 962 Wayne Ave., Silver Spring, MD 20910.
- For television transmissions, the L-M system makes no attempt to
monitor the direct signal from the transmitter, since most of the power
is in the carrier anyway. For FM transmissions, the L-M system does measure
the direct path signal and correlates it with the
signal which bounces off the target.
- The polarization characteristics of the transmitted signal vary from
station to station. For FM signals, there is some emphasis on vertically
polarized signals, since most car antennas are vertical.
- It would be useful to collect data from the L-M system while using an
optical camera to visually track and identify aircraft in order to get
“ground truth.” It might be especially helpful to conduct such experiments
at a small, low-activity airport, in order to cut down on background clutter
and generally make the data easier to analyze.
- Some experiments on detecting and tracking a car going in circles
in a parking lot showed that the background clutter introduced by other
moving objects in the scene can be a significant effect. Also, there were
duplicate doppler signatures corresponding to other information in the TV
signal. These duplicate signatures were 13 to 20 db down from the main
- The FCC has a database of information about radio and television
transmitters in the U.S., including latitude, longitude, etc.
- The LM system receives on four bands – VHF low (2-6), VHF high
(7-13), UFH, and FM. Beamforming is performed digitally.
Notes from the Afternoon Meeting
The afternoon focused on potential areas of investigation and
- Target identification/estimation
- Basic detection
- Different levels of classification
- Position estimation (especially altitude)
- Orientation estimation (linked to tracking)
- Performance bounds
- Target Imaging
- Useful for targets which may not be in a classifier’s library
- Linear methods
- Dependence of reflectance on aspect angle
- Use of multiple receiving antennas
- Dependence on source bandwidth & locations
- Autofocus (phase alignment issues)
- Nonlinear methods
- Areas applicable to both ID and imaging
- Principles of multistatic radar systems
- Use of polarization information
- Collection of experimental data
- Simulated data: XPATCH, FISC, etc.
- Comparison of simulated and real data
- Techniques based on electromagnetic models
- System design (Ex: best place to put sensors)
- Role of tracking: motion dynamics, track association