The detection and avoidance of external hazards is an important aspect of overall efforts to improve the safety of future
aircraft. Advanced sensor concepts may enhance the detection and quantification of risk due to external hazards. Such
sensors, when integrated into cockpit operations, may substantially improve vehicle safety. This paper will describe
research efforts to develop a simulation environment to evaluated advanced microwave sensor concepts such as airborne
bistatic radars utilizing multiple non-cooperative illuminators or emitters-of-opportunity to detect weather hazards, area
traffic, runway incursions, or other potential aircraft hazards.
We will present initial efforts to develop a flexible microwave sensor simulation and assessment tool. This tool will be
developed to assess the feasibility of various sensor concepts. Existing and potential future capability of the simulation
environment will be described. In addition, the results of the application of the simulation tool to a bistatic sensor
concept will be presented.
The Global Positioning System (GPS) consists of a constellation of Earth orbiting satellites that transmit continuous electromagnetic signals to users on or near the Earth surface. At any moment of time, at least four GPS satellites, and sometimes nine or more, are visible from any point. The electromagnetic signal transmitted from the satellites is reflected to at least some degree from virtually every place on the Earth. When this signal is received by a specially constructed receiver, its characteristics can be used to determine information about the reflected surface. One piece of information collected is the time delay encountered by the reflected signal versus the direct signal. This time delay can be used to determine the altitude (or height) above the local terrain when the terrain in the reflection area is level. However, given the potential of simultaneously using multiple reflections, it should be possible to also determine the elevation above even terrains where the reflecting area is not level. Currently an effort is underway to develop the technology to characterize the reflected signal that is received by the GPS Surface Reflection Experiment (GSRE) instrument. Recent aircraft sorties have been flown to collect data that can be used to refine the technology. This paper provides an update on the status of the instrument development to enable determination of terrain proximity using the GPS Reflected signal. Results found in the data collected to date are also discussed.