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Calibration and corrections

FarEarth performs calibration and applies corrections automatically to all Earth observation imagery.

Calibration is performed in different stages of the mission.

Pre-launch imager validation​

Before you launch, lab data is used to calculate the initial calibration parameters for an imager. A raw data decoder and sensor model for each individual satellite is created.

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To guide you through this phase, we provide you with a FarEarth Launch Pack.

Commissioning calibration​

The initial images will be used to validate downlinked data, and generate PR images.

FarEarth tracks and records your raw data metrics, including ephemeris, navigation, attitude, and temperature, to help with the commissioning of a new satellite. In-orbit calibration parameters are calculated in this phase and will be used to process and correct your images in the operational phase.

At the end of this phase, we provide you with an In-orbit Calibration Report that includes metrics on radiometric and geometric accuracy, as well as SNR, MTF, and effective GSD measurements.

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To guide you through this phase, we provide you with a FarEarth Space Pack.

Corrections​

FarEarth compensates for your satellite-specific anomalies with scientific accuracy. It performs complex precision refinement for each image.

Below is a list of typical corrections FarEarth performs.

Denoising

  • Readout noise
  • Dropped scanline interpolation
  • Focus sharpening
  • Navigation & attitude (NavAtt) filtering

Band alignment

  • Precision band alignment
  • Correct for viewing angle offsets

Geometry

  • Precision pointing correction
  • Terrain correction
  • Orthorectification
  • Multi-sensor mosaicking
  • Map projection

Top-of-atmosphere radiometry (Level 1C)

  • Dark-current correction
  • Vignetting & non-uniformity correction
  • Radiance modelling
  • Reflectance conversion
  • Brightness temperature conversion

Bottom-of-atmosphere radiometry (Level 2A)

  • Aerosol detection
  • Emissivity estimation
  • Surface reflectance modelling
  • Surface temperature product generation

Continuous calibration - Operational phase​

Once commissioning is completed, FarEarth can automatically process data at scale. Continuous re-calibration over the lifetime of your satellite will ensure that the accuracy of your imagery remains consistent.

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The FarEarth Orbit Pack explains the ins and outs of daily operations.