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Version: 2.0-beta

Processing Levels

When placing an order for satellite imagery, users can select the desired processing level to best suit their needs.

Level-2A Surface Reflectance

Level-2A products are surface reflectance imagery that have undergone atmospheric correction and reprojection to a projected map coordinate system. These products are designed for users who don't have unique atmospheric correction requirements and prefer ready-to-use data for analysis.

Key Features

Pixel Units and Scale

  • Units for surface reflectance are unitless, represented as an empty string ("") in the metadata.
  • Delivered as a raster dataset with 16-bit floating point (uint16) data type.
  • Pixel values are scaled integers with a scale factor (i.e., 0.0001) to convert to float reflectance. This approach optimizes file size storage while maintaining precision.
  • Example:
    {
    "nodata": 0,
    "sampling": "area",
    "data_type": "uint16",
    "unit": "",
    "scale": 0.0001,
    "offset": 0
    }

Consistent Reprojection and Pixel Size

  • Reprojected to Universal Transverse Mercator (UTM) / WGS84, with the UTM zone and hemisphere determined by the center pixel of the image scene.
    • Example:
      "proj:epsg": 32611
  • Output pixel size is 5 m x 5 m in the projected coordinate system.
  • All downstream products (imagery, masks, etc.) use the same projection and pixel size for consistency.

Geometric accuracy

  • Wyvern's Level-2A products have the same geometric accuracy as Level-1B and are not orthorectified. We plan on improving the geometric accuracy in future releases.

Level-1B Top-of-Atmosphere Radiance

Level-1B products are hyperspectral imagery that have been geometrically corrected to a map-projected north-up Geographic WGS84 (EPSG:4326) coordinate system and radiometrically corrected to top-of-atmosphere radiance. These products are suitable for advanced analytical techniques and industry-standard radiometric and geometric processing.

Key Features

Geometric Correction and Coordinate System

  • Imagery is georeferenced to Geographic WGS84 (EPSG:4326).
    • Example:
      "proj:epsg": 4326
  • The spatial X & Y cell size of each pixel is defined in angular longitude & latitude degrees.
  • Pixel cell size is set to the angular degree equivalents of 5 m x 5 m at the latitude of the image center.
  • Pixel cell size in will be non-square and vary based on latitude (e.g., at 40°N: Lon=0.0000586° x Lat=0.0000450°).

Radiometric Correction and Pixel Units

  • Delivered as a raster dataset with 32-bit floating point (float32) data type.
  • Pixel values represent top-of-atmosphere (TOA) radiance.
  • Units are 'W / (m² * sr * µm)' (watts per square meter per steradian per micrometer).
  • No scaling factor is required; values are in physical units.
  • Example:
    {
    "nodata": -9999,
    "sampling": "area",
    "data_type": "float32",
    "unit": "W⋅sr-1·m-2·µm-1",
    "scale": 1.0,
    "offset": 0
    }

Metadata and Analytical Applications

  • Metadata enables radiometric & geometric data processing and advanced analytics (deep learning, machine learning, spectral indices, classification, anomaly detection, material identification, sub-pixel mixture analysis, spectral target detection).