THE REMOTE SENSING GROUP (RSG) AT THE UNIVERSITY OF ARIZONA USES THE REFLECTANCE-BASEDAPPROACH TO RADIOMETRICALLY CALIBRATE AIRBORNE AND SPACEBORNE SENSORS IN THE SOLAR-REFLECTIVESPECTRAL RANGE (40~2500 NM). IN ORDER TO INCREASE THE AMOUNT OF GROUND-BASED DATA COLLECTS THERADIOMETRIC CALIBRATION TEST SITE (RADCATS) CONCEPT WAS DEVELOPED IN 2004. IT PROVIDES AMETHODOLOGY TO DETERMINE THE SURFACE REFLECTANCE FOR ANY ARBITRARY TEST SITE IN THE ABSENCE OFGROUND PERSONNEL. IT IS FOUNDED ON THE REFLECTANCE-BASED APPROACH AND HAS SUCCESSFULLY OPERATEDAT RAILROAD VALLEY NEVADA WITH A SUITE OF INSTRUMENTS INCLUDING NADIR-VIEWING MULTISPECTRALRADIOMETERS A CIMEL SUN PHOTOMETER AND A METEOROLOGICAL STATION. RAD.CATS DATA ARE CURRENTLYUSED BY RSG TO SUPPLEMENT THOSE COLLECTED BY ON-SITE PERSONNEL. FOR EXAMPLE RECENTCOMPARISONS BETWEEN THE RADCATS RESULTS AND THOSE OBTAINED WITH LANDSAT 7 ENHANCED THEMATICMAPPER PLUS (ETM+ ) LANDSAT 8 OPERATIONAL LAND IMAGER (OLI) AND TERRA MODERATE RESOLUTIONIMAGING SPECTROMETER (MODIS) SHOW THAT THE AVERAGE PERCENT DIFFERENCE BETWEEN THE SIX BANDSOF ETM+ AND RADCATS IS 1.1%. THE SEVEN MULTISPECTRAL BANDS OF OU SHOW AN AVERAGE PERCENTDIFFERENCE OF 0.1% WITH RADCATS AND THE SEVEN LAND BANDS OF TERRA MODIS SHOW AN AVERAGEPERCENT DIFFERENCE OF 1.1% WITH RADCATS.IN 2011 THREE IMPROVED GROUND-VIEWING RADIOMETERS (GVRS) WERE BUILT AND DEPLOYED TO SUPPORT RADCATS. A FOURTH GVR WAS FUNDED AND IT WAS DEPLOYED IN OCTOBER 2014. THE GVRS ARE FILTERBASED RADIOMETERS WITH EIGHT SPECTRAL CHANNELS COVERING A WAVELENGTH RANGE OF 400-1550 NM.THEY ARE AUTOMATED TEMPERATURE-CONTROLLED FIELD-DEPLOYABLE INSTRUMENTS THAT ARE CAPABLE OFLONG-TERM STANDALONE OPERATION.IN 2014 RESEARCH INVOLVING THE RADCATS GVR CALIBRATION METHODOLOGY RESULTED IN THE CONCEPTUAL MODEL OF A SMALL AND ULTRA-PORTABLE FIELD TRANSFER RADIOMETER (TR). THE GVR TR CONCEPT WAS CREATED TO REPLACE THE SOLAR-RADIATION-BASED CALIBRATION (SRBC) AS A MEANS OF THE ON-SITECALIBRATION EVALUATION OF THE RADCATS GVRS. PRELIMINARY DESIGN WORK SHOWS THAT THE GVR TR IS AGOOD OPTION NOT ONLY FOR ON-SITE CALIBRATION BUT ALSO AS A MEANS OF A CALIBRATION TRANSFER BOTH INTHE FIELD AND IN THE LABORATORY. THE GVR TR TRAVELLING STANDARD CONCEPT LED RSG TO PROPOSE WORKTHAT IS BENEFICIAL TO NASA'S INTEREST IN AUTOMATED VICARIOUS CALIBRATION INCLUDING THE CEOSRADIOMETRIC CALIBRATION NETWORK (RADCAINET) CONCEPT.