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MakeItera

Create an ITERA file from GPS data

For some aerial image flights, GPS data is available for all exposure stations, but no ground control points are available in the area. In this situation, RELAX cannot transform the flight into a ground coordinate system. Instead, RELAX writes orientation data in a local coordinate system to the ITERA file, enabling a free-network bundle adjustment.

Alternatively, the GPS data can be used to create an ITERA file in the target coordinate system. The given GPS coordinates are used as the projection-center coordinates. Phi and omega are set to zero for all photos, and kappa is estimated from the flight direction.

If heading values are provided, they are used for kappa instead of values derived from the flight direction.

Six input formats are supported:

  • PhotoID, Easting, Northing, Height
  • PhotoID, GPStime, Easting, Northing, Height
  • PhotoID, Easting, Northing, Height, Heading in degrees (360)
  • PhotoID, Easting, Northing, Height, Heading in gon (400)
  • PhotoID, GPStime, Easting, Northing, Height, Heading in degrees (360)
  • PhotoID, GPStime, Easting, Northing, Height, Heading in gon (400)

Input is format-free. Output is in ITERA file format.

If the camera's x' axis does not point in the flight direction, modify the kappa value by selecting the button that corresponds to the photo coordinate system as mounted in the aircraft. Depending on the selected button, 0, 100, 200, or 300 gon is added.

Heading angles provided in degrees are converted to gon during input.

The program recognizes flight lines and separates them in the ITERA file with a blank line.

See also the transformation options in HEL3D.

Default values​

To reset all parameters, select Settings > Set Parameter Defaults.