The harmonize tool in the Orders API radiometrically harmonizes imagery captured by one satellite instrument type to imagery captured by another.

Supported inputs

• Item type: PSScene
• Product bundles: analytic_8b_sr_udm2 and analytic_sr_udm2

Note: Only the two surface reflectance bundles above are supported.

Parameter

• target_sensor (string, required): the sensor to calibrate the input data to. The only supported value is Sentinel-2.

Sentinel-2 target sensor

• PSScene surface reflectance assets from PlanetScope instrument types PS2.SD and PSB.SD can be harmonized to Sentinel-2.
• The tool harmonizes to the Sentinel-2 blue, green, red, red-edge, and narrow near-infrared (NIR) bands.
• Results differ slightly between 8-band and 4-band data, even for the same scene. This comes from a regularization metric that minimizes changes in band ratios during harmonization.

For details, see Scene Level Normalization and Harmonization of Planet Dove Imagery.

Example request

{
  "name": "harmonize_example",
  "products": [
    {
      "item_ids": [
        "20211008_002442_03_2456"
      ],
      "item_type": "PSScene",
      "product_bundle": "analytic_sr_udm2"
    }
  ],
  "tools": [
    {
      "harmonize": {
        "target_sensor": "Sentinel-2"
      }
    }
  ]
}

Outputs

• One imagery output file with harmonized band values is delivered for each product bundle.
• The transformation of each item depends on the instrument used to capture that item and its relationship to the target sensor.
• Transformed files have _harmonize appended to their file names.
• The tool passes through UDM, RPC, and XML files.

Related articles

• Orders API tools: Harmonize