Changelog | Hydrosat Docs

May 21, 2026: Footprint Geometry Correction
We've deployed a minor fix to ensure representativeness of STAC item footprint geometries with actual imaged area.

March 31, 2026: Coregistration Improvements
We've refined our mutual information-based coregistration workflow for improved feature matching between the LWIR and VNIR data.

February 24, 2026: Geometric Processing Improvements
We've updated our georeferencing and VNIR band alignment workflows to improve geolocation accuracy and band-to-band registration. This release includes:

1. An enhanced optical distortion correction to reduce residual along-track offsets
2. Use of a digital elevation model (DEM) to improve band-to-band registration over complex terrain

February 5, 2026: Level-1 Unit Changes
We've modified the units for our Level-1A and Level-1B data products.

Before The Change

Previously, L1A and L1B imagery assets contained per-band digital number data. To arrive at radiance, the user needed to apply gain and offset coefficients provided in product metadata.

After The Change

Level-1A Products

• L1A imagery assets now natively contain per-band top-of-atmosphere (TOA) radiance values. Gain and offset coefficients are applied as part of Hydrosat's data processing.

  • Units: W/m2/sr/μm
  • Scaling factor: 0.01 (VNIR), 0.0001 (LWIR)

Level-1B Products

• L1B imagery assets contain per-band TOA reflectance data (for VNIR bands) and brightness temperature data (for LWIR bands).

  • Units: Unitless (VNIR); Kelvin (LWIR)
  • Scaling factor: 0.0001 (VNIR); 0.01 (LWIR)

Conversions

• Hydrosat provides a full suite of coefficients in product metadata for conversion between TOA radiance and reflectance (or brightness temperature). For more information on usage, see this page or our product guide.

January 27, 2026: Thumbnail Colorization Improvements (LWIR)
We've improved the contrast and visual consistency in our L1B and L2 thermal thumbnails and previews. This includes:

• Consistent scaling across the full imaging strip rather than within individual scenes.
• A switch from the inferno color ramp to a modified RdYlBu_r color ramp, where cooler pixels are shown in blue and warmer ones in red. These colors map to predictable temperatures; the breakpoint from blue to yellow occurs at approximately 0 degrees Celsius.

This change has no impacts on the underlying data.

January 20, 2026: Noise Mitigation
We've implemented a minor correction for noise in the thermal products.

January 14, 2026: Thumbnail Colorization Improvements (RGB)
We've released a color curve approach that improves the visual contrast in our true color thumbnails. This change has no impacts on the underlying data.

December 17, 2025: Updated Cloud Mask
We've released an improved cloud mask, which uses a U-Net convolutional neural network architecture. The new model outperforms our baseline Fmask approach across several key metrics.