Autonomous deployment of the UAVSAR radar instrument

The UAVSAR program was formed to provide repeat pass radar interferometry on an uninhabited aircraft platform. The UAVSAR imaging radar system is housed in an external unpressurized pod that may be attached to an Uninhabited Aerial Vehicle (UAV), although initial flight tests were performed aboard a Gulfstream-III aircraft with flight test personnel on-board. Since the radar science missions are to be eventually flown without an on-board operator, all data collection must be performed autonomously from take-off to landing. The Automatic Radar Controller (ARC) is the main instrument flight computer responsible for a myriad of tasks, including commanding the radar configuration and monitoring the aircraft flight path to search for data collection waypoints provided by an on-board flight plan. The pod environment and various hardware units are monitored during the mission to assure the radar instrument remains within an operable range. The ARC communicates with a Radar Operator Workstation (ROW) to receive updated real-time operational commands and to download up-to-date hardware status and telemetry. The ROW provides operator displays for monitoring the health of the radar system and also displays sampled radar waveforms in time and frequency domains. The aircraft location is provided by the on-board GPS/INU and downloaded by the ARC for plotting the current location onto Google maps using software developed at JPL. The UAVSAR platform has been flown throughout most of California and has recently completed successful deployments to Greenland and the Aleutian Islands. A nearly identical UAVSAR pod will be attached to a Global Hawk UAV platform in early 2010 for uninhabited operational flight tests. An additional pod containing another L-band antenna and GPS/INU unit will also be attached to the Global Hawk platform providing dual Lband data collection capability. The command and communication implementation for Global Hawk has been modified from the original GUI test U- - .S. Government work not protected by U.S. copyright ? IEEEAC paper#1558, Version 1, Updated 2009:10:27 platform. During flight tests on the GUI the Radar Operator Workstation (ROW) was on-board with the test team. For the Global Hawk flight tests, the Radar Operator Workstation will be in the Global Hawk Operations Center located at the Dryden Flight Research facility. Communications to the ARC will utilize a relatively low speed Iridium satellite communications link. This paper will describe the functionality of the UAVSAR Global Hawk radar instrument flight and ground systems. We will also discuss fault detection and recovery options provided by these systems. We will describe the capabilities of monitoring and controlling the radar instrument during flight from the Global Hawk operations facility and describe the operational timeline for a typical science mission.