Integrating On-board and Vicarious Calibration with the Improved Radiometric Calibration of Land Imaging Systems (IRIS)

As part of Raytheon’s effort to provide innovative calibration capabilities that advance the performance of future earth imaging systems, an on-board Jones source calibrator integrated with vicarious SPecular ARray Calibration (SPARC) is introduced. The Improved Radiometric calibration of land Imaging Systems (IRIS) is a compact full-spectrum calibration system that reduces the size, weight, and power of conventional on-board radiometric sources into a single flat panel format providing high spatial illumination uniformity. Combining both carbon nanotube and LED technology within a Jones source design, IRIS offers a common assembly calibration reference covering the spectral range from 0.4 to 12 μm. On-board calibrator degradation from the effects of launch and lifetime exposure to the space environment impacts performance, making it difficult to maintain absolute knowledge of the sensor radiometry. What has been missing from past on-board lamp calibration systems is an operational capability for establishing and maintaining absolute SI traceability in the solar reflective spectral range after launch and over the sensor lifetime. Introduced in this presentation is a methodology that sustains traceability through a fusion of the on-board IRIS LED reference with Labsphere’s FLARE vicarious system. In this process, the imager collects an on-board calibration source image nearly simultaneously with observations of the sun safely reflected by a FLARE array of convex mirrors on the ground. The process known as IRIS-V provides data for recalibration of the onboard VSWIR system, as needed, in-flight without affecting operational land or coastal image collection. A prototype of the IRIS on-board calibrator and IRIS-V methodology will be described. IRIS is funded by the NASA Earth Science Technology Office (ESTO) through the Sustainable Land Imaging-Technology 2019 (SLIT19) Program

LCROSS (Lunar Crater Observation and Sensing Satellite) Observation campaign : strategies, implementation, and lessons learned

NASA's LCROSS (Lunar Crater Observation and Sensing Satellite) mission was designed to explore the nature of previously detected enhanced levels of hydrogen near the lunar poles. The LCROSS mission impacted the spent upper stage of the launch vehicle into a permanently shadowed region of the lunar surface to create an ejecta plume. The resultant impact crater and plume were then observed by the LCROSS Shepherding Spacecraft as well as a cadre of telescopes on the Earth and in space to determine the nature of the materials contained within the permanently shadowed region. The Shepherding Spacecraft then became a second impactor which was also observed by multiple assets. The LCROSS Observation Campaign was a key component of the LCROSS mission. The goal of the Observation Campaign was to realize the scientific benefits of extending the LCROSS observations to multiple ground and space-based assets. This paper describes the LCROSS Observation Campaign and provides an overview of the Campaign coordination and logistics as well as a summary of the observation techniques utilized at a multitude of observatories. Lessons learned from the LCROSS Observation Campaign are also discussed to assist with the planning of future unique observing events.48 page(s