The En Route Descent Advisor (EDA) is one of the Center TRACON Automation System (CTAS) decision support tools under development at the NASA Ames Research Center. EDA generates maneuver advisories for arrival aircraft to meet scheduled arrival times at the arrival meter fix, sometimes 20 -25 minutes ahead of the aircraft's scheduled meter fix arrival time. This work determined the sensistivity of the EDA advisories to system uncertainties, including initial condition, environmental, and aircraft performance data errors. Using a Monte Carlo simulation that incorporates a Matlab Trajectory Synthesizer (TS) simulation, the sensitivities of the EDA predicted trajectory to these data error sources were obtained. The key metric is the meter fix crossing time error since this metric directly measures the performance of EDA. This performance analysis involved a minimum of 200 Monte Carlo trials per error parameter. In addition to the single aircraft performance analysis, the impact of aircraft prediction errors on conflict detection between closely-spaced aircraft was also explored. These Monte Carlo performance analyses determined how robust the EDA advisories are to input parameter uncertainties. Nomenclature

This paper describes data collection and test results from an airborne ground penetrating radar (GPR) sensor operating as a synthetic aperture radar (SAR). Tests were undertaken to investigate the sensor's capability to support wide-area airborne minefield detection. The sensor was installed on a rotorcraft unmanned aerial vehicle (UAV). Flight tests occurred in 2002/3 at several US Army test sites containing minefields comprised of diverse types of anti-tank landmines, both metallic and low-metallic, that were buried and surface-laid. Data was collected using two side-look SAR modes: strip-map and spotlight. Strip-map mode data was collected using linear flight paths. Spotlight mode data was collected over a path surrounding the survey region allowing the sensor to collect minefield data over a full 360º view in azimuth. Data collected in strip-map mode was processed to form two-dimensional SAR imagery of the minefields. Three dimensional images were generated by processing the 360º spotlight mode data. The images were generated in a geo-referenced coordinate system to allow direct comparison of the imagery with surveyed ground truth. The sensor system is described and the flight tests that were undertaken are explained. Examples of SAR imagery from the flight tests are presented and compared to surveyed ground truth.

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