Antenna autocalibration and metrology approach for the AFRL/JPL space based radar
Dalia A McWatters - Jet Propulsion Laboratory, California Institute of Technology, Thierry R. Michel - Jet Propulsion Laboratory, California Institute of Technology, Vaughn P. Cable - Jet Propulsion Laboratory, California Institute of Technology, Adam P. Freedman - Jet Propulsion Laboratory/California Institute of Technology
Tue, 27 April 2004, 10:20 AM - 12:00 PM
Abstract- The Air Force Research Laboratory (AFRL) and the Jet Propulsion Laboratory (JPL) are collaborating in the technology development for a space based radar (SBR) system that would feature a large aperture lightweight antenna for a joint mission later in this decade. This antenna system is a 50m x 2m electronically steerable phased array in L-band (1260 MHz center frequency, 80 MHz bandwidth) and contains 384 x 12 Transmit/Receive modules. The radar is designed to operate in a variety of modes including Synthetic Aperture Radar (SAR) and Moving Target Indication (MTI). Stringent requirements are placed on phase center knowledge and antenna sidelobe levels during a data take, in the presence of temperature changes due to the orbital thermal environment, self heating, spacecraft platform vibrations, and mechanical deformation. We present an auto-calibration and metrology system concept to correct for phase errors and mechanical deformation during the mission.
Ms. Dalia A McWatters - Jet Propulsion Laboratory, California Institute of Technology
Dalia A. McWatters received the B.Sc. degree in electrical engineering from California State University, Long Beach, in 1985 and the M.Sc degree in electrical engineering from University of California, Los Angeles in 1989.
Since 1985 she has been with the Jet Propulsion Laboratory (JPL), Pasadena, CA working on various projects involving design, analysis and testing of ground and flight Radio Frequency (RF) systems. She was RF Electronics Subsystem Lead Engineer for the Shuttle Radar Topography Mission for which her responsibilities included design, integration and testing of the dual-frequency and dual-polarization receiver and transmitter, beam auto-tracker, and the calibration optical phase locked loop. Her responsibilities progressed into testing and integration with the space shuttle at Kennedy Space Center and finally, into mission operation in Houston, TX, during the successful 11 day mission in Feb. 2000. During 2001-2002 Dalia was program manager at Phasebridge, a fiber optic component start-up company. She then returned to JPL where she is working on space borne radar system design.
Thierry R. Michel - Jet Propulsion Laboratory, California Institute of Technology
Thierry R. Michel received his Ph.D. in Physics from the University
of California at Irvine in 1990.
He is currently a member of the technical staff at the Jet Propulsion
Dr. Vaughn P. Cable - Jet Propulsion Laboratory, California Institute of Technology
Vaughn Cable received his BSE and MSE degrees from California State University, Northridge and his PhD degree in EE from the Ohio State University. Dr.Cable currently holds a position of Senior Engineer in the Spacecraft Antennas Research Group of JPL and he is also manager of the Mesa Antenna Measurement Facility. His tasks since coming to JPL have included measurement of MER Cruise/Rover antennas, development of antenna measurement error budget protocol, and computational modeling of SIRTF patch antenna patterns and MRO UHF antenna multipath. He was also PI for a DRDF collaboration with Caltech to improve JPL's multipath modeling capabilities. Prior to coming to JPL in 2000, Dr. Cable spent 13 years with Lockheed Martin working in the areas of radar signature control and radar subsystems design. Dr. Cable currently holds a part time faculty position with California State University, Northridge were he teaches undergraduate and graduate courses in electromagnetics. He is also a regular reviewer for IEEE AP-S and has authored or co-authored more than 30 professional presentations and peer reviewed papers.
Dr. Adam P. Freedman - Jet Propulsion Laboratory/California Institute of Technology
Adam P. Freedman is a Senior Engineer at the Jet Propulsion Laboratory/Caltech in Pasadena, California, where he has worked since 1987. Prior to coming to JPL, he received a B.S. in Physics from Yale University in 1980 and a Doctorate in Geophysics from the Massachusetts Institute of Technology in 1987. From 1987 to 1996, Dr. Freedman studied the phenomenology and prediction of Earth rotation variations to facilitate improved spacecraft navigation and to address several global geophysical problems. From 1996 to 2003, he participated in the development of the GeoSAR, aircraft-based, interferometric synthetic aperture radar, topographic mapping system, leading the motion measurement and analysis effort. He is currently performing systems engineering for several proposed space-based radar systems.