Editing Camera Properties File

       Ribbon: Point Clouds > Aerial Laser Scanning >  Edit camera properties

       Menu: Point Clouds > ALS >  Edit camera properties

       Toolbar: ALS >  Edit camera properties

    Comamnd line: PC_EDIT_CAMERA

The command opens the Camera dialog box, where you can create and edit a camera file, as well as load and save it in the TerraPhoto camera calibration file format.

 

Width and Height. The width and height of an image in pixels. This is a mandatory parameter and cannot be equal to 0. It is used to verify that the image matches the camera.

Margins. Margins at the image edges in pixels. This parameter indicates how many pixels at the edges of the image are not used. It allows cropping the image edges with significant geometric or radiometric distortions.

Time offset. This value is added to the time of taking a photograph.

Focal length. A mandatory parameter, cannot be equal to 0. Must be known from the camera specifications.

Principal point. Coordinates of the principal point in pixels relative to the center of the frame. The X-axis is directed to the right, the Y-axis – downwards.

Level arm. The camera’s displacement vector relative to the antenna in the aircraft’s coordinate system. The X-axis is directed to the right, the Y-axis – forward, the Z-axis – upwards.

Misalignment angles. Camera misalignment angles relative to the inertial system. These angles are usually calculated as a result of calibration. Before calibration, these angles should be left at zero.

Radial distortion. Classic Brown coefficients are used for conversion from a real to an ideal image. Compared to TerraPhoto distortion models:

·      - TerraPhoto Function model. K0 = 0, K1 = -A, K2 = -B, K3 = -C

·      - TerraPhoto Balanced function model. K0 = -K0, K1 = -K1, K2 = -K2, K3 = 0

·      - TerraPhoto Homogenous model. K0 = 0, K1 = 0, K2 = 0, K3 = 0

The TerraPhoto Zero radius function and Grid models are not supported.

Tangential distortion. Coincides with the TerraPhoto coefficients.