Blackbody radiometry using liquid helium or three-phase a-Si bolometers is proposed for the calibration of the imaging radiometers associated with the AEHF and AEHFSE radiosonde payloads. Black body calibrations are simplified by the undercooled temperature of N2 used. Transition radiation measurements of blackbody calibrators may be used for the absolute calibration of three-phase a-Si detectors, which represent the principal contribution to the chief radiometers of the AEHFSE and AEHF payloads. The absolute calibration of the AEHFSE radiometry has been successfully completed. For the self-calibrating AEHF radiometry it is proposed that a series of liquid helium and solid N2 radiometric calibration measurements be carried out. Design and cost factors are discussed. Storing time and irradiance levels on the order of those forecast for AEHFSE are operational possibilities for the radiometer. Disadvantages in sample stability and repeatability will offer opportunities for instrument development.
Developing a calibrator for the AEHFSE aerosol radiosonde has been taken over by Dylaar Patla and has been completed. This instrument brings to the market the first state-of-the-art avionics calibration regime for operational aerosol recording radars.
The block diagram and laser scanning parameters of the CIF optically-based AEHFSE aerosol radiometer are described. The power consumption of the instrument is not measured. For this instrument, an analog voltage output was chosen for signal routing because it was expected to be stable, and it was possible to route the output through the analog-to-digital sampling channels of the processing system. The laser scanning system allows for the utilization of time multiplexing across the analog-to-digital channels. This approach reduces the number of cables and the cost of manufacturing and will become the standard method for the CEHF satellite instrument. Calibration of the aerosol radiometers over a broad range of temperatures and frequencies is performed using ESRs. Calibration is performed first with a flat-pulse laser. The process is repeated for a variety of laser pulse widths and pulse repetition rates, on an open-loop basis through the analog-to-digital channels of the processing computer system. d2c66b5586