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Projection System

This documentation is also applicable to projection configuretion whilst using it in AngelScript.

Basic example

This is the simplest projection that will automatically create a GeoTIFF image (for later use in other software) of the proper size and projected using the equirectangular projection. It will then be explained further later.

"Composite Name": {
   "equation": "ch2, ch2, ch1",
   "project": {
      "config": {
         "type": "equirec",
         "auto": true,
         "scalar_x": 0.016,
         "scalar_y": -0.016
      },
      "draw_map_overlay": true,
      "filters": [
                    [
                        "equalize",
                        [
                            true,
                            {
                                "per_channel": true
                            }
                        ]
                    ]
                ],
      "img_format": ".tif"
   }
}

Projection types

type :

  • equirec (equirectangular)
  • stereo (sterographic)
  • utm (Universal Transverse Mercator)
  • geos (for geostationary satellites)
  • tpers (Tilted PERSpective)
  • webmerc (Web Mercator)

Common parameters for all projections

These can be omitted in automatic mode, or can be set anyway to override. If they are omitted but needed, they default to zero.

  • lat0 (float) Latitude of the origin of the projection
  • lon0 (float) Longitude of the origin of the projection
  • offset_x (float) Offset of the projection from the center (in meters)
  • offset_y (float) Offset of the projection from the center (in meters)
  • scalar_x (float) Scale of the projection (in meters per pixel)
  • scalar_y (float) Scale of the projection (in meters per pixel)

Extra parameters for UTM

  • zone: (int) UTM zone
  • south: (boolean) if you\'re north (false) or south (true) of the equator

Extra parameters for GEOS

  • altitude: (float) Altitude of the satellite (in meters)
  • sweep_x: (boolean) Sweep mode of the GEOS projection

Extra parameters for TPERS

  • altitude: (float) Altitude of the satellite (in meters)
  • tilt: (float) Tilt of the satellite (in degrees)
  • azimuth: (float) Azimuth of the satellite (in degrees)

Alternative mode for Stereo

Mandatory:

  • center_lat (float) Latitude of the center of the projection (degrees)
  • center_lon (float) Longitude of the center of the projection (degrees)
  • scale (float) Scale of the image(meters per pixel)
  • width (int) Width of the image (in pixels)
  • height (int) Height of the image (in pixels)

Alternative mode for TPERS

Mandatory:

  • center_lat (float) Latitude of the center of the projection (degrees). Set this to 0 to project a geostationary satellite.
  • center_lon (float) Longitude of the center of the projection (degrees). Set this to the satellite's longitude (e.g. 76°E for Elektro-L N°3) to project a geostationary satellite.
  • scale (float) Scale of the image(meters per pixel)
  • width (int) Width of the output image (in pixels)
  • height (int) Height of the output image (in pixels)
  • altitude: (float) Altitude of the satellite (in meters). Set this to 36000e3 to have the normal altitude of a geostationary satellite.

Optional:

  • tilt: (float) Tilt of the satellite (in degrees)
  • azimuth: (float) Azimuth of the satellite (in degrees)

Alternative mode for UTM

Mandatory:

  • scale (float) Scale of the image(meters per pixel)
  • width (int) Width of the image (in pixels)
  • height (int) Height of the image (in pixels)

Optional:

  • zone: (int) UTM zone
  • south: (boolean) if you\'re north (false) or south (true) of the equator