The New C/NOFS Neutral Wind Instruments: Laboratory and Flight Validation Results
G. D. Earle1, J. H. Klenzing1, P. A. Roddy2, and E. L. Patrick3
- William B. Hanson Center for Space Sciences, The University of Texas at Dallas, USA
- Air Force Research Laboratory, Hanscom AFB, USA
- Southwest Research Institute, San Antonio, TX, USA
The US Air Force plans to launch the Communication/Navigation Outage Forecast System (C/NOFS) satellite in 2008, with the goal of establishing the feasibility of predicting the onset of equatorial spread F. Two of the sensors aboard the satellite have never before flown in a LEO environment, yet they are critical to overall mission success. Both sensors measure the bulk motion of the neutral gas in the spacecraft reference frame; the cross-track sensor (CTS) is designed to measure motions transverse to the satellite’s velocity, and the ram wind sensor (RWS) is designed to measure the velocity component along the orbit track. In this talk we present the results of validation tests for both sensors. For the CTS this comprises flight data from two suborbital sounding rocket flights, one of which was flown in conjunction with independent chemical release measurements from a companion rocket. Validating the capabilities of the RWS cannot be achieved via a sounding rocket, so a laboratory-based study was undertaken using a heated nozzle with argon and hydrogen gases in a free-jet expansion geometry. Results of both validation efforts will be presented in order to establish likely operational limits on the accuracy and sensitivity to be expected during the C/NOFS mission.