INVESTIGATION OF THE FEASIBILITY OF A DOPPLER RADAR TECHNIQUE TO MEASURE FREE STREAM VELOCITY IN THE AFFDL ELECTROGASDYNAMICS FACILITY.
Final rept. Jul 67-Apr 68,
CORNELL AERONAUTICAL LAB INC BUFFALO NY
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An experimental investigation was performed to determine the feasibility of measuring free stream velocity in the Air Force Flight Dynamics Laboratory AFFDL 50 Megawatt Electrogasdynamics Facility EGF with a pulse doppler radar technique. After feasibility was confirmed, a brief series of tests were undertaken to investigate the effect of ablating models on radar cross section of the hypervelocity flow. The experiments were performed with the CAL X-band one-nanosecond coherent pulse doppler radar instrument. In the experimental investigations, the radar instrument used detected electromagnetic EM signals backscattered from electron number density irregularities which occur naturally in the arc heater processed air. The doppler shift of the EM signal provided a direct measure of equivalent free stream velocity. A measure of radar cross section of the gas flow was derived from analysis of amplitude of the doppler signals. In a second series of tests, the doppler signals from wakes behind cones and a truncated sphere were observed. Author
- Test Facilities, Equipment and Methods
- Active and Passive Radar Detection and Equipment