Digital Signal Processing Radiometer For The Investigation of Background Noise Stationarity

Design of a novel digital signal processing (DSP) radiometer system is proposed, which combines a low-noise, high stability radio frequency (RF) down-converter, a high speed digitizer with a deep buffer memory, and a personal computer running an innovative DSP software known as X-Midas. X-Midas allows the user to construct a software DSP system by selecting functional blocks through a user-friendly interface and has many other novel features. For accurate time and position determination, a Global Positioning System (GPS) receiver is included. A communications link for connecting other radiometer instruments permits correlated measurements or may be used to geo-locate emitters. The resulting measurement receiver can easily be software reconfigured to perform many difficult measurement tasks, such as evaluation of spread-spectrum low-probability of intercept (LPI) communications and radar systems. The initial task of such an instrument will be to investigate the RF background noise environment at 316 MHz, 1 GHz, and 3.16 GHz, and determine background noise stationarity as a function of center frequency, bandwidth, integration time, time of day, date, antenna pattern, altitude and location.