The Aerial Triangulation Menu

The Aerial Triangulation menu contains the next subdivisions related to the following subjects:

1. Interior Orientation.
2. Observations - Tiepoints.
3. Control Points.
4. Object Points.
5. Bundle Block Adjustment.

This menu shows a submenu giving choice between two new items:

The next dialog will show up, giving you the possibility between different approaches to determine the interior orientation parameters:

See the chapter on Fiducial Marks for more details about the procedures.

This method lets you save a report about the interior orientation.
A fileselection box will popup, select a path and enter a filename for the report.

A typical report is structured as in the next example:

The Observations menu shows a submenu with the following choices:

A new dialog will popup :

This dialog shows a listing of the available images in the project.

To measure a tiepoint:

1. Select the images in which you want to measure a tiepoint.
2. Press the 'Select' button to continute with the measurement.
3. See the chapter on Manual Tiepoint Measurements for further detailed description.

All tiepoint measurements are kept together with the image it is measured in.
The tiepoints are therefore saved when saving the project, in the project file.

Remember that you also can edit the existing tiepoints using the 'Tiepoints...' menu function of the 'View Menu'.

All the measured observations (tiepoints) can be listed in a report.
The report contains the image name, the focal distance and the tiepoints that are measured in that image.
When clicking on the 'Save Observations' button, the file containing the report is automatically saved next to the project.spr file.
The name of file is: ({Projectname} Observations.txt).
There is also a file created containing the image measurements expressed in pixel units called ({Projectname} ObservationsInPixelUnits.txt).
This last file is the best way to exchange measurements between different project files.

Different observations can be done by different people.
Afterwards the observations can be exported and imported into one definitive project.

This menu function opens a dialog for entering control points into the project.

See the chapter on Edit Control Points.

This menu function shows a submenu with the following choices:

This method calculates approximate values for the projection centres and for the object points.

A tiepoint coordinate is the coordinate of an image detail that corresponds to a certain object in the destination (ground) coordinate system. This detail on the ground is called an object point. Tiepoints with the same name, measured in different images, correspond all to the same objectpoint in the destination coordinate system. The coordinates of these object points are also refered to as 'the objectpoints'.

In a new photogrammetric project, after determining the tiepoints, there exist no destination coordinates yet for the corresponding object points. This is obvious because the tiepoints are selected randomly. The overal adjustment procedure however needs the object points coordinates to be able to proceed. Therefore Strabo calculates approximations for these object points. This procedure produces at the same time approximate values for the projection centres.

Just select the menu item 'Calculate Approximations' to start the calculation. When the block is big, this calculation can take a long time, this is also depending on the processor speed.

As an alternative to the calculation of the approximate values of the object points, and when a set of coordinates is available, they can be introduced in the project by reading a file.

See the chapter on Object points for further details.

The object points are saved together with other parameter while saving the project. With this menu function you can save the object points on another location. This is of course only meaningful after completing an adjustment procedure, because the object points will then be more precise.

This function clears the object points list.

This menu function shows a submenu with the following choices:

See the Bundle Block Adjustment chapter for further details.