Design of a Ground Based Power and Ambiguity Function Monitor for P-Band Signals of Opportunity Sources

Abstract

Signals of Opportunity (SoOp) remote sensing utilizes existing non-cooperative microwave transmitters as sources of illumination. Knowledge of the SoOp source's Effective Isotropic Radiated Power (EIRP) is required for accurate calibration of a SoOp instrument. A SoOp instrument using a digital communication signal also assumes temporal consistency of the signal's ambiguity function. The Wideband Year-round AmbuguiTy-function Tracking Effective Isotropic Radiated Power (WYATT EIRP) instrument uses an array of RHCP and LHCP antennas, mounted on a rotating antenna pedestal. A secondary observation antenna is placed to allow time difference of arrival measurements for validating satellite positions and potential use in orbit determination. WYATT EIRP will provide temporal monitoring of P-Band SoOp sources EIRP and self-ambiguity function. It will also be used to validate existing P-Band background noise temperature sky maps as well as orbit elevation verification of the P-Band transmitter. The system design is outlined in this paper as well as the theoretical derivation of the measurement retrieval. WYATT EIRP will be installed in the Spring of 2022 and will be used to provide calibration data to the upcoming spaceborne SigNals Of Opportunity: P-Band Investigation (SNOOPI) instrument.