Aerotraingulation step by steps in 3d aerial photogrammetry

Aerotraingulation Data Inputs in 3d aerial photogrammetry. This is a continuation of the previous post.

1.Digital images (Example: by DMC Camera)
Analog images by RC20 Camera

2. Camera calibration report
The calibration report contain the information about calibration dates, serial number, sensor size, pixel size, focal length, radial distortion, Decentering distortion, plane distortion, camera orientation, camera protocol etc. which is used to set up the camera wizard.

3. IMU data
The IMU data receives in Microsoft Excel sheets which contain the information about X, Y, Z in meters, Omega, Phi, and Kappa; image IDs, Projection system, Zone etc.
From the received data, seven parameters that is X, Y, Z (elevation), Omega, Phi, Kappa analog with image IDs were than taken into Ultra Edit software and saved in .txt format so that it can be used in the project setup.

4. GCP points and locations (Ground Survey)
GCP point’s information is also available in the Microsoft Excel sheets which contain the GCP Id, X, Y and Z (elevation) information. The .pdf contain photographs of GCP point location which provide the exact view of the place where is had been measured. The .pdf also contains the projection and datum information, project name, point Id, coordinates etc.

Softwares used:

1. LPS
2. SSK kit (Image station)
3. Socket set
4. Match AT
5.Vr Mapping
6. Bingo

Orientation Procedure In AT

Interior orientation

Exterior orientation
             a. Relative orientation
             b. Absolute orientation

Interior orientation
in Aerotraingulation in 3d aerial photogrammetry
Interior orientation establishes a relationship between the camera and the raster coordinate system.
If the images are taken from analog camera, then interior orientation is to be performed.
 On each image, depending on camera, four or eight fiducial marks are present. The image captured from analog camera contains the information of fiducial marks, flying direction, date on which the image was taken, strip id, photo id etc.
 Since the digital images were used in this project, there was no need of performing interior orientation. In case of digital images the step of interior orientation is not necessary. We just provide information regarding the pixel size.
Once the operator has performed interior orientation, he can determine the image coordinates of any point measured on the image. During this process, the operator can measure fiducial points.
The interior orientation is the measurement of four or eight fiducial marks on each photo.

Exterior orientation in
Aerotraingulation in 3d aerial photogrammetry

Exterior orientation describes the location and orientation of an image in the object coordinate system.
A total of six transformation parameters per image are typically chosen for such an orientation, namely projection center coordinates (Xo, Yo, and Zo) and three rotations (omega, phi and kappa).
 The definition of the sequence of rotations has to be preserved. Most often, the successive rotations of the sequence omega, phi, kappa or phi, omega, kappa are used.
A transformation from one rotation system to the other can be made – the angular values are different, but the numerical values of the corresponding rotation matrix are identical.

Relative orientation

Absolute orientation in
Aerotraingulation in 3d aerial photogrammetry

During relative orientation, one image is oriented with respect to the other using image rays, which intersect on the ground. After relative orientation, model stereoscopic view is possible. We applied pass points and tie points on the images.