Abstract
L-1 Standards and Technology has completed the ground characterization and calibration for a commercial 10-satellite Earth observing constellation, which consists of 120 VNIR, 24 SWIR, and 24 TIR imagers. L-1 was responsible for calibrating the VNIR and SWIR imagers. Details of the mission can be found at: https://spacenews.com/engineeringbehind- earthdaily-solving-for-global-daily-coverage-scientific-quality-and-high-spectral-diversity/
The L-1 calibration system allows the complete end-to-end characterization over the entire spectral range of interest on a per pixel basis with measurements performed at discrete wavelengths. The techniques employed mirror those used at the NIST SIRCUS facility and NASA’s GLAMOUR facility. The absolute spectral response is tied directly to NIST through L-1 transfer standard detectors spectrally calibrated at the NIST SIRCUS facility. The system enables full-aperture illumination (testing as the sensor is used) and provides direct measurement of the absolute response as a function of wavelength to uncertainties of less than 1 % (k==2) in at VNIR wavelengths. Additional characterizations include linearity and flat-fielding measurements to the 0.1 % level, and stray light rejection, e.g., size-of-source and off-axis response. Characterization can be performed over a range of temperatures that simulate the expected on-orbit imager thermal environment.
Pre-launch Characterization and Calibration of an Earth Observing Satellite Constellation (144 Imagers) using Tunable Laser Sources
L-1 Standards and Technology has completed the ground characterization and calibration for a commercial 10-satellite Earth observing constellation, which consists of 120 VNIR, 24 SWIR, and 24 TIR imagers. L-1 was responsible for calibrating the VNIR and SWIR imagers. Details of the mission can be found at: https://spacenews.com/engineeringbehind- earthdaily-solving-for-global-daily-coverage-scientific-quality-and-high-spectral-diversity/
The L-1 calibration system allows the complete end-to-end characterization over the entire spectral range of interest on a per pixel basis with measurements performed at discrete wavelengths. The techniques employed mirror those used at the NIST SIRCUS facility and NASA’s GLAMOUR facility. The absolute spectral response is tied directly to NIST through L-1 transfer standard detectors spectrally calibrated at the NIST SIRCUS facility. The system enables full-aperture illumination (testing as the sensor is used) and provides direct measurement of the absolute response as a function of wavelength to uncertainties of less than 1 % (k==2) in at VNIR wavelengths. Additional characterizations include linearity and flat-fielding measurements to the 0.1 % level, and stray light rejection, e.g., size-of-source and off-axis response. Characterization can be performed over a range of temperatures that simulate the expected on-orbit imager thermal environment.