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In Part I of this paper, the infrared bands of the Moderate Resolution Imaging Spectroradiometer (MODIS) are analyzed for volcanic ash signals using principal component image analysis. Target volcanoes included Popocatepetl volcano near Mexico City and Cleveland volcano in the Aleutian Islands. The analyses were performed to determine the MODIS bands that contribute the most to detecting volcanic ash. Even though the explained variance and signal-to-noise ratio of most of these new images are generally small, several of them provide views of volcanic ash with good contrast to the image background and other image features. Both day and night examples indicate that volcanic ash can be readily detected by combinations of MODIS bands to determine not only the ash extent but also qualitative variations in the concentration and height of the ash. The 36 bands on MODIS give much more flexibility for ash detection than the 4 bands on the current Geostationary Operational Environmental Satellite (GOES) Imager. In particular, MODIS bands 28-32, in the water vapor and longwave infrared portions of the spectrum, contributed most frequently to the detection of airborne volcanic ash. These include bands 28-30 in the 7.3-9.7-[micro]m portion of the spectrum known for volcanic signals. Several of the MODIS bands that proved useful are bands projected for inclusion in the next major upgrade to the GOES Imager (scheduled for 2012). However, band 30 (9.7 [micro]m) is neither available on the current GOES series nor planned for future GOES Imagers. In Part II of this paper, MODIS data for the same volcanic cases examined in Part I are used for specific simulations of current and near-term GOES imagery. The purpose of the simulations is to assess the impact of changes that will occur in the spectral bands of the GOES-M Imager (launched in 2001 and renamed GOES-12) when it becomes operational.

On June 11, 2000, the first vicarious calibration experiment in support of the Multi-angle Imaging SpectroRadiometer (MISR) was conducted. The purpose of this experiment was to acquire in situ measurements of surface and atmospheric conditions over a bright, uniform area. These data were then used to compute top-of-atmosphere (TOA) radiances, which were correlated with the camera digital number output, to determine the in-flight radiometric response of the on-orbit sensor. The Lunar Lake Playa, NV, was the primary target instrumented by the Jet Propulsion Laboratory for this experiment. The airborne MISR simulator (AirMISR) on board a NASA ER-2 acquired simultaneous observations over Lunar Lake. The in situ estimations of top-of-atmosphere radiances and AirMISR measurements at a 20-km altitude were in good agreement with each other and differed by 9% from MISR measurements. The difference has been corrected by adjusting the gain coefficients used in MISR standard product generation. Data acquired simultaneously by other sensors, such as Landsat, the Terra Moderate-Resolution Imaging SpectroRadiometer (MODIS), and the Airborne Visible and Infrared Imaging Spectrometer (AVIRIS), were used to validate this correction. Because of this experiment, MISR radiances are 9% higher than the values based on the on-board calibration. Semiannual field campaigns are planned for the future in order to detect any systematic trends in sensor calibration. Index Terms--Calibration, MISR radiometric calibration, vicarious calibration.

Each of the nine cameras that compose the Multiangle Imaging SpectroRadiometer (MISR) has been rigorously tested, characterized, and calibrated. Requirements on these tests include a 3% (l[Sigma]) radiometric calibration requirement, spectral response function determination of both the in- and out-of-band regions, and distortion mapping. The latter test determines the relative look-angle to the ground corresponding to each focal plane detector element. This is established to within one-tenth of the instantaneous field-of-view. Most of the performance testing was done on the cameras as they completed assembly. This was done to take advantage of the serial delivery of the hardware, minimize the required size of the thermal-vacuum facilities, and allow testing to occur early in the schedule allocated for the hardware build. This proved to be an effective strategy, as each of the test objectives was met. Additional testing as an integrated instrument included verification of the data packetization, camera pointing, and clearances of the fields-of-view. Results of these studies have shown that the MISR cameras are of high quality and will meet the needs of the MISR science community. Highly accurate calibration data are on-hand and available for conversion of camera output to radiances. Index Terms - Calibration, image sensors, testing.

Experiments on the scientific applications of a far infrared imaging radiometer was conducted. The radiometer tested was equipped with picture-element arrays of quantum-well detectors which were fused to a high-capacity, silicon integrated-circuit multiplexer. Results show that the radiometer can be used by scientific laboratories for remote sensing and thermal measurements which could also be developed for astronomical use.