IONOSPHERIC SCINTILLATION MONITORING FOR C3I

VARIOUS DOD C3I COMMUNICATIONS SYTEMS CAN BE SERIOUSLY AFFECTED BY THE DISTURBANCES IN THE EARTH'S IONOSPHERE. ONE WAY TO ALLEVIATE THIS PROBLEM IS TO USE ALTERNATE C3I ASSETS DURING THE TIMES OF PREDICTED SIGNAL OUTAGES DUE TO IONOSPHERIC SCINTILLATION FADING. HOWEVER, CURRENT PREDICTION THECNIQUE BASED ON MONTHLY CLIMATOLOGY OF INOSPHERIC FADING DOES NOT PROVIDE REAL-TIME SOLUTIONS. PAST EXPERIMENTS USING SIGNALS BROADCAST FROM THE NAVSTAR GLOBAL POSITIONING SYSTEM (GPS) SATELLITES TO MEASURE AMPLITUDE AND PHASE SCINTILLATION IN REAL TIME HAVE BEEN SUCESSFUL. BUT THE COST OF THESE GPS RECEIVERS IS VERY HIGH RENDERING THEM IMPRACTICAL TO BE DEPLOYED IN LARGE NUMBER IN A THEATRE BATTLEFIELD ENVRIONMENT. A VERY INEXPENSIVE IONONSPHERIC SCINTILLATION MONITOR (ISM) BASED ON STATE-OF-THE-ART HIGH-PERFORMANCE COMMERCIAL GPS RECEIVER IS PROPOSED. PHASE I EFFORT WILL PRODUCE A PROTOTYPE ISM CAPABLE OF MEASURING, IN REAL TIME, THE AMPLITUDE SCINTILLATION INDEX AND THE PHASE JITTER. DETRENDING ALGORITHMS TO REMOVE THE EFFECTS OF RECEIVER OSCILLATOR PHASE NOISE AND GPS SELECTIVE AVAILABILITY WILL BE DEVELOPED AND EXPERIMENTED DURING PHASE I.