NISTAR: An Overview of Calibration and Ground Processing Techniques for Irradiance Measurements from L1
Abstract
The NIST Advanced Radiometer (NISTAR) is required to provide measurements to determine the total outgoing irradiance of Earth in the spectral range of 0.2-100 μm (total channel) with an accuracy of 1.5% or better. Secondary goals are to provide similar accuracy levels for irradiance measurements in the total solar reflected channel (0.2-4 μm) and the near-IR solar reflected channel (0.7-4 μm). Current absolute calibration techniques and parameters are provided. In addition, the various instrument operating modes and ground processing algorithms are discussed. The primary challenges involve thermal load variability, both via the spacecraft's position in the Lissajous orbit (and the orientation with respect to the sun) and via the heating and cooling of internal components during operations. Results exceed accuracy requirements for the total and solar reflected channels, but fall short for the near-IR solar reflected channel. The low noise photodiode provides calibration data for monitoring degradation of the filters and radiometer relative responsivities.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFM.A23D0263B
- Keywords:
-
- 0321 Cloud/radiation interaction;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 3311 Clouds and aerosols;
- ATMOSPHERIC PROCESSESDE: 3359 Radiative processes;
- ATMOSPHERIC PROCESSESDE: 3360 Remote sensing;
- ATMOSPHERIC PROCESSES