GPS bias

For projects processed with both camera GPS and GCPs, the GPS bias describes a transform from the (GCP-adjusted) camera output positions to the prior camera GPS positions.

Format specification

Specification format	Version
“application/opf-gps-bias+json”	“1.0”

---

GPS bias

For projects processed with both camera GPS and GCPs, the GPS bias describes a transform from the (GCP-adjusted) camera output positions to the prior camera GPS positions. For an output camera point p, a camera GPS point p’ is computed as p’ = RigidTransformation(p). Note that both the GPS and camera positions are in the processing CRS. A GPS bias is a rigid transformation with rotation, translation, and scaling.

GPS bias Properties

	Type	Description	Required
format	string	For the GPS bias it must be "application/opf-gps-bias+json"	✓ Yes
version	string	The version of this schema as MAJOR.MINOR. Breaking changes are reflected by a change in MAJOR version. Can optionally include a pre-release tag MAJOR.MINOR-tag. Examples: 0.1, 1.0, 1.0-draft1	✓ Yes
transform	rigid_transform	Rigid transform	✓ Yes
extensions	object	JSON object with extension-specific objects. Extensions follow the naming convention VENDOR[_(team❘product)]_extname	No

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Rigid transformation with scaling

Definition of a rigid transformation with rotation, translation, and scaling. Transforms input points p to output points p’ via p’ = scale * rotation * p + translation.

Rigid transformation with scaling Properties

	Type	Description	Required
rotation_deg	number [3]	Rotation as Euler angles in degree (see convention here)	✓ Yes
translation	number [3]	Translation in units of the processing CRS.	✓ Yes
scale	number	Scale	✓ Yes
extensions	object	JSON object with extension-specific objects. Extensions follow the naming convention VENDOR[_(team❘product)]_extname	No

Example

{
    "format": "application/opf-gps-bias+json",
    "version": "1.0",
    "transform": {
        "rotation_deg": [
            1.3256,
            -2.1467,
            1.6216
        ],
        "translation": [
            5.302,
            3.089,
            -35.246
        ],
        "scale": 1.0
    }
}