In November of 2000, the Deputy Under Secretary of Defense for Science and Technology Sensor Systems (DUSD (S&T/SS)) chartered the ATR Working Group (ATRWG) to develop guidelines for sanctioned Problem Sets. Such Problem Sets are intended for development and test of ATR algorithms and contain comprehensive documentation of the data in them. A problem set provides a consistent basis to examine ATR performance and growth. Problem Sets will, in general, serve multiple purposes. First, they will enable informed decisions by government agencies sponsoring ATR development and transition. Problem Sets standardize the testing and evaluation process, resulting in consistent assessment of ATR performance. Second, they will measure and guide ATR development progress within this standardized framework. Finally, they quantify the state of the art for the community. Problem Sets provide clearly defined operating condition coverage. This encourages ATR developers to consider these critical challenges and allows evaluators to assess over them. Thus the widely distributed development and self-test portions, along with a disciplined methodology documented within the Problem Set, permit ATR developers to address critical issues and describe their accomplishments, while the sequestered portion permits government assessment of state-of-the-art and of transition readiness. This paper discusses the elements of an ATR problem set as a package of data and information that presents a standardized ATR challenge relevant to one or more scenarios. The package includes training and test data containing targets and clutter, truth information, required experiments, and a standardized analytical methodology to assess performance.
This report briefly reviews the development, capabilities, and current status of pulsed high-power coherent CO2 laser radar systems at the Maui Space Surveillance System (MSSS), HI, for acquisition, tracking, and sizing of orbiting objects. There are two HICLASS systems, one integrated to the 0.6 m Laser Beam Director and one just integrated Summer 2000 to the 3.7 m Advanced E-O System (AEOS). This new system takes full advantage of the large AEOS aperture to substantially improve the ladar range and sensitivity. These improvements make the AEOS HICLASS system potentially suitable for tracking and characterization experiments of small < 30 cm objects in low-earth-orbits.
Proc. SPIE. 3065, Laser Radar Technology and Applications II
KEYWORDS: Human-machine interfaces, Digital signal processing, Detection and tracking algorithms, Doppler effect, LIDAR, Image processing, Data acquisition, Signal processing, Target acquisition, Signal detection
A kilowatt class, pulsed CO2 laser radar has been developed at Textron under a joint US Army-Air Force program. It is currently undergoing field trials; and successful coherent imaging and tracking experiments have been conducted over the past two years at the Air Force Maui Space surveillance Site. This paper describes the receiver- processor architecture of the laser radar system, the algorithms and waveforms, and the output products which are high resolution range-Doppler and range-amplitude image. Attention will be paid to the hardware and software methods used to achieve real-time, wideband operations.
Proc. SPIE. 2847, Applications of Digital Image Processing XIX
KEYWORDS: Digital signal processing, Detection and tracking algorithms, Doppler effect, Imaging systems, LIDAR, Image processing, Data acquisition, Signal processing, Target acquisition, Signal detection
Textron has designed and built a high-powered CO2 laser radar for long range targeting and remote sensing. This is a coherent, multi-wavelength system with a 2D, wide-band image processing capability. The digital processor produces several output products from the transmitter return signals including range, velocity, angle, and 2D range-Doppler images of hard-body targets (LADAR mode). In addition, the processor sorts and reports on data acquired from gaseous targets by wavelength and integrated path absorption (LIDAR mode). The digital processor has been developed from commercial components with a SUN SPARC 20 serving as the operator workstation and display. The digital output products are produced in real time and stored off-line for post-mission analysis and further target enhancements. This LADAR is distinguished from other designs primarily by the waveforms produced by the laser for target interrogation. The digital processing algorithms are designed to extract certain features through operation on each of the two waveforms. The waveforms are a pulse-tone and a pulse-burst designed for target acquisition and track, and 2D imaging respectively. The algorithms are categorized by function as acquisition/track, 2D imaging, integrated absorption for gaseous targets, and post mission enhancements such as tomographic reconstruction for multiple looks at targets from different perspectives. Field tests are now in process and results acquired from Feb.-June '96 will be reported on. The digital imaging system, its architecture, algorithms, simulations, and products will be described.
A multi-joule, wavelength agile, CO2 transceiver is being assembled in support of a two phase, airborne chemical sensing demonstration employing both direct (Phase I) and coherent (Phase II) detection methods. The Phase II, coherent detection transceiver concept design, and performance are described below.
The High Performance CO2 Ladar Surveillance Sensor system (HI-CLASS) is a state-of-the-art coherent ladar system which will provide precision tracking and high resolution imaging at the Air Force Maui Optical Station (AMOS). System development is occurring in 3 phases representing increasing hardware/software complexity and system capability. The recently-completed Phase I HI-CLASS system employs a compact, pulsed, coherent CO2 oscillator, a heterodyne receiver, and signal recorder coupled to the AMOS 0.6 m Laser Beam Director to demonstrate target (satellite) acquisition and tracking, illumination, return signal detection, signal recording, and off-line processing for range and range rate extraction and range- amplitude imaging. A description of the Phase I satellite ranging and ground-based remote sensing tests verifying the FLD system operating concept will be presented. The cooperative target range and range rate measurements, as well as imaging precursor demonstration, will be discussed. The talk will include a discussion of the 21 km demonstration of remote sensing using natural terrain returns. Results generated on phase I data with the phase II algorithm will also be described.
Both EO and AO modulators can be used to extend the spectral coverage of CO2 lasers in the 9 - 11 micrometers region. For laser radar local oscillator application, the spectral purity of the frequency shifter output must be high and can be achieved with an AO frequency shifter using a special modulator configuration and a molecular absorption technique. A 500 MHz AO frequency shifter was designed, tested and shown to have a high spectral purity at an output power level of over 50 mW with a conversion efficiency of a few percent.
HI-CLASS (FLD) Laser Radar Produces 2D range-Doppler images, range-amplitude images, azimuth and elevation offsets and whole body range and Doppler estimates of rapidly moving space based targets. The Receiver-Processor converts the return signature on two selectable waveforms into a heterodyned signal which is subjected to conditioning and normalization in the receiver (e.g., extraction of gross Doppler) and then operated on within the processor, primarily convolution and Fourier transformation, to produce the output products in real time at the operator's workstation. This paper will show the instrument design, and provide a look at some of the parametric trade-offs considered in arriving at the final operating configuration. Details of the hardware, and software architectures will be presented, and the algorithms required for acquisition, tracking, and imaging will be explained.
Mode-locked CO2 lasers have been developed which can produce long coherent pulse trains consisting of many narrow subpulses. This laser waveform may be used to numerically generate range-Doppler images (inverse synthetic aperture radar images) of a target wherein the Doppler spread of a spinning target is used to create a synthetic cross-range target dimension. The narrow micro-pulse temporal width provides good range resolution, and the long coherent pulse train provides good frequency resolution of the (cross-range) target Doppler spread. In this paper we examine the algorithms and imaging capabilities of this waveform as implemented for the FLD and Hi-CLASS laser radar (ladar) systems which are now being installed in the AMOS facility on Mt. Haleakala, Maui and in an aircraft testbed.
Automatic Target Recognition algorithms have been developed with limited
success over the last few years. The processing to extract military targets from
background clutter has difficulty under noisy, real-world conditions. Fusion of
data from different wavelength sensors has been one approach to improve
performance. The underlying theory is that signature data from different areas
of the electro-magnetic spectrum will be complementary and clutter is frequency
dependent. Recent work based on both statistical classification, and feature
analysis in the thermal infrared and millimeter wave spectra, has shown
interesting trends. We will provide a description of the IR/MMW target
classification algorithms, the fusion architecture we employed, and processes
used to search for the optimum features. Two distinct search and detect
schemes were tested with different results. Data acquisition and reduction
issues which affect algorithm experiments will also be discussed. A software
based algorithm development test-bed was built at Textron to implement the
multispectral targeting experiments. The effect of a modular, programmable
test-bed on such experiments is to increase productivity and allow multivariate