BOARDBAND SOURCE DEVELOPMENT FOR A THREE-DIMENSIONAL REFLECTOMETER

THE TECHNOLOGY TO TAKE FULL HEMISPHERE REFLECTIVE OR TRANSMISSIVE SCATTER MEASUREMENTS WITH FULLY AUTOMATED POSITION AND POLARIZATION CONTROL OF THE INSTRUMENT NOW EXISTS. ADOPTION OF THIS TECHNOLOGY WILL RESULT IN AN INSTRUMENT WHICH IS HIGHLY COMPATIBLE IN TERMS OF OPERATION AND DATA OUTPUT WITH OTHER GOVERNMENT RESEARCH LABORATORIES. TWO SIGNIFICANT INNOVATIVE DESIGN FEATURES ARE PROPOSED TO EXTEND THE CURRENT STATE OF THE ART. FIRST IS A NEW SOURCE DESIGN TO ACHIEVE THE SPECIFIED WAVELENGTH COVERAGE. CONVENTIONAL DESIGNS USE BLACKBODY SOURCES AND BANDPASS FILTERS WITH LIMITED RESOLUTION CHOICES AND SOURCE POWER. AN ALTERNATIVE APPROACH USING A MONOCHROMATOR HAS VARIABLE WAVELENGTH RESOLUTION BUT IS ALSO LIMITED IN POWER OUTPUT. THE MOST INNOVATIVE SOURCE DESIGN USES THE FTIR (FOURIER TRANSFORM INFRARED) SPECTROMETER. IT SHOULD RESULT IN HIGHER PERFORMANCE INSTRUMENTATION BECAUSE OF THROUGHPUT AND EFFICIENCY ADVANTAGES. THE SECOND INNOVATION PROPOSED HERE IS IN THE MEASUREMENT OF THE FOUR STOKES PARAMETERS. A BRUTE FORCE APPROACH REQUIRES BROADBAND WAVEPLATES TO PRODUCE AND MEASURE THE REQUIRED POLARIZATION COMPONENTS. THERE ARE TWOALTERNATIVES; ONE THAT IS EASIER EXPERIMENTALLY AND ONE MORESUITABLE TO AUTOMATION THAN THE BRUTE FORCE METHOD.