Calibration and validation.

Technologies

• Pre-flight and onboard calibration Laboratory and onboard references (lamps, diffusers, blackbodies) that set sensor radiometry and spectral response.
• Vicarious calibration and test sites Instrumented reference sites and pseudo-invariant desert sites that check sensors in orbit.
• Inter-calibration of satellite instruments Tying instruments to common references so long records and multi-mission stacks stay consistent.
• Fiducial reference measurements In situ measurements with documented, SI-traceable uncertainty used to validate satellite products.
• SAR calibration targets Corner reflectors and transponders that calibrate radar amplitude, phase and geolocation and anchor InSAR.
• Geometric accuracy and ground control Surveyed control points and check points that quantify positional accuracy of imagery and lidar.
• Product validation stages Comparison of derived products with independent reference data, reported against agreed validation stages.
• In situ match-up networks Sun photometers, flux towers, buoys and profilers co-located with overpasses for routine match-ups.