PORTABLE MICROWAVE RADIOMETER FOR REAL-TIME REMOTE SENSING OF ATMOSPHERIC WATER VAPOR TO IMPROVE GLOBAL POSITIONING SYSTEM (GPS) ACCURACY

PROTOTYPE MICROWAVE RADIOMETERS CAPABLE OF MEASURING ATOMSPHERIC WATER VAPOR AND LIQUID BY OBSERVATION OF LINE-OF-SIGHT EMISSION AT 20.6 AND 31.6 GHZ RESPECTIVELY ARE NOW IN USE AT SEVERAL RESEARCH LABORATORIESS. THESE PROTOTYPE RADIOMETERS ARE BULKY, EXPENSIVE TO BUILD, AND ARE NOT AVAILABLE COMMERCIALLY. THERE IS A GROWING DEMAND FOR THESE INSTRUMENTS FOR USE IN GEODETIC, RADIO ASTRONOMY, AND METEOROLOGICAL APPLICATIONS. A RECENT SURVEY VERIFIES THIS DEMAND, IDENTIFYING RESEARCH REQUIREMENTS FOR APPROXIMATELY 60 MICROWAVE WATER VAPOR RADIOMETERS. WE HAVE RECENTLY DEMONSTRATED THE POTENTIAL OFA COLLOCATED WATER VAPOR RADIOMETER (WRC) TO IMPROVE GPS POSITIONING ACCURACY TEN-FOLD. IN PHASE I OF THIS PROJECT WE WILL EVALUATE AND PROPOSE APPROPRIATE MODIFICATIONS TO T THE DESIGN AND CONFIGURATION OF EXISTING RESEARCH RADIOMETERS TO MAKE THEM PORTABLE, DRIFT-FREE, AND MORE COST EFFECTIVE. IN PHASE II WE WILL USE DESIGN CONCEPTS FROM THE PHASE I EFFORT TO BUILD A THIRD GENERATION DUAL WAVELENGTH RADIO METER AND TEST IT EXTENSIVELY. IN PHASE III WE WILL MAKE ANOPERATIONAL OFF-THE-SHELF INSTRUMENT COMMERCIALLY AVAILABLE TO THE SCIENTIFIC USER COMMUNITY. THE POTENTIAL COMMERCIAL AND GOVERNMENT APPLICATIONS, IF OUR MICROWAVE WATER VAPOR RADIOMETER(WVR) IS SUCCESSFULLY DEVELOPED IN PHASE I & II, INCLUDE WEATHER FORECASTING, CLOUD PHYSICS STUDIES, WEATHER MODIFICATION PROGRAMS, SOLAR RADIATION STUDIES, GEODITIC METEROLOGY, PRECISE GLOBAL POSITIONING USING NAVSTAR/GPS SATELLITES EXCESS RADIO TRANSMISSION LENGTH CORRELATIONS, RADIO ASTRONOMY INTERFEROMETRY, AND CLIMATOLOGICAL HEAT BALANCE RESEARCH.