Using Lunar Observations to Validate Pointing Accuracy and Geolocation, Detector Sensitivity Stability and Static Point Response of the CERES Instruments

Validation of in-orbit instrument performance is a function of stability in both instrument and calibration source. This paper describes a method using lunar observations scanning near full moon by the Clouds and Earth Radiant Energy System (CERES) instruments. The Moon offers an external source whose signal variance is predictable and non-degrading. From 2006 to present, these in-orbit observations have become standardized and compiled for the Flight Models -1 and -2 aboard the Terra satellite, for Flight Models-3 and -4 aboard the Aqua satellite, and beginning 2012, for Flight Model-5 aboard Suomi-NPP. Instrument performance measurements studied are detector sensitivity stability, pointing accuracy and static detector point response function. This validation method also shows trends per CERES data channel of 0.8% per decade or less for Flight Models 1-4. Using instrument gimbal data and computed lunar position, the pointing error of each detector telescope, the accuracy and consistency of the alignment between the detectors can be determined. The maximum pointing error was 0.2 Deg. in azimuth and 0.17 Deg. in elevation which corresponds to an error in geolocation near nadir of 2.09 km. With the exception of one detector, all instruments were found to have consistent detector alignment from 2006 to present. All alignment error was within 0.1o with most detector telescopes showing a consistent alignment offset of less than 0.02 Deg

Joint Polar Satellite System (JPSS) Instrument Transition to NASA and Development Status

The Joint Polar Satellite System (JPSS) Program is a cooperative program between the National Aeronautics and Space Agency (NASA) and the National Oceanic and Atmospheric Administration (NOAA) to design, develop, and fly the next suite of US civilian polar orbiting environmental sensing instruments. The JPSS Program is a product of the restructuring of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Program, which occurred in 2010. With the transition to NASA, the JPSS instruments have undergone significant review with numerous updates to the designs as well as made significant progress toward delivering a superior capability to the Nation. This paper will discuss the program transition as it relates to the instruments and the associated transition review efforts, key findings, important changes to the instruments for JPSS and their current development status. The VIIRS instrument will be presented separately