Optical tracking of airborne targets typically involves initial acquisition by radar at long range and relatively high measurement error. The target is then passed to an electro-optical tracker with a WFOV and precision tracking begins. The problem can include a second handoff to a NFOV sensor for additional resolution. A stringent mission time line requires these handoffs to be executed quickly. In this paper, traditional approaches to these handoff problems are reviewed and a new solution is presented at the system level. The authors discuss problems uncovered in the integration and testing phase and show results from an extensive HWIL testing platform.
The control system, software design and implementation issues for a large, 15,000 pounds, high accuracy, high dynamics, low jitter multi-axis gimbal set, optical Beam director Assembly are discussed in this paper. The definite success of the Contraves Brashear Systems approach to design and implement these unique systems is discussed and results shown.
An addressable mosaic array of resistively heated microbridges offers much flexibility for infrared scene simulations. In the Wide Band Infrared Scene Projector program, Honeywell has demonstrated high yield arrays up to size 512 X 512 capable of room temperature operation for a 2 band infrared projection system being designed and built by Contraves Inc. for the Wright Laboratory Kinetic Kill Vehicle Hardware In-the-Loop Simulator facility at Eglin Air Force Base, FL. The arrays contain two different pixel designs, one pixel designed for kHz frame rates and high radiance achieved at a power level of 2.5 mWatts/pixel and the other pixel designed for more moderate 100 Hz frame rates at lower radiance and at maximum power levels of 0.7 mWatts/pixels. Tests on arrays and pixels have demonstrated dynamic ranges up to 850:1, radiance rise times on the order of 2 mseconds, and broadband pixel emissivities in the range of 70%. Arrays have been fabricated with less than 0.1% pixel outages and no row or column defects. These arrays are mounted in a specialized vacuum assembly containing an IR window, vacuum package, cooling block, and pump out manifold.
generating a high degree of uniformity across the FOV in infrared scene simulators, over a wide dynamic range, is necessary to avoid introducing unintentional structure into the projected image. One challenge for calibration is establishing measurement of the radiance outputs of each of the 256,000 individuals pixels to the required accuracy levels at several radiance levels, within a reasonable time, with available instrumentation. Issues affecting measurement accuracy include the aperture, focal length, blur circle, and IFOV characteristics of the non-uniformity calibration (NUC) sensor, geometric and diffraction blur characteristics of the collimator optics (which vary with field position), NUC sensor noise and stability (temporal and spatial), emitter pixel geometry and temperature profile, and the relationship between the spectral characteristics of the NUC sensor and the source. Analyses are presented which determine the limitations on calibration accuracy based on predicted and measured performance of the WISP projector and the NUC sensor components. Some NUC sensor accuracy data, needed to support the determination of the overall process parameters, was collected in special NUC sensor tests and is presented herein. A combination of NUC process parameters is developed which achieves optimum accuracy in performing the NUC calibration, and which is expected to achieve the necessary calibrated uniformity performance of 1% for WISP.