EXTERIOR ORIENTATION
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This is a module calculating relative and exterior orientation elements.
The exterior orientation is calculated for photgrammetric photos using bundles. The orientation may be carried out for one model or a block of photos. To carry out an exterior orientation you should first carry out an Interior Orientation.
After this stage, open a project in the module's window or in Open Project menu by selecting it. The project has to be opened in the Manager programme.
When you open the Exterior Orientation module, the Points dialogue appears to manage the data introduced into calculations of relative and exterior orientation.
When the dialogue is closed you can open it using the Show Dialog button, as below.
showdialog

Photos Selection
Exterior Orientation – Relative Orientation
Exterior Orientation




Photos Selection

To show photos open the dialogue using the Open photos dialogue
open FOto
indicate the desired strip as active (First strip, Second srip ...) and select First photo, which is the first photo number. In the Number position define the number of displayed photos, and Delta determines the frequency of displaying photos.
Adjust a photo size to your needs. To display photos enlargements select Zoom below Photo in the Arrange bookmark. Enlargements will be displayed below the general view.
To arrange photo zoom select an appropriate command from the Toolbar menu or click the mouse's right button (controller's button no.3) and then a new dialogue to select commands is displayed:

Menu in photos field
 
Select pointAlt+S   – select a point by showing it on a photo. The selected point will be highlighted on the zoom and in the Points dialogue  
Set point Alt+E   – point measurement  
Transfer pointAlt+R   – display the point selected on the second photo. To use this function you need at least two measured points.  
Zoom InAlt+Z   – enlarge a photo  
Zoom OutAlt+X   – reduce a photo  
Zoom AllAlt+A   – show all  
Show zoom windowAlt+W   – show a window with enlargement  
Show photosAlt+D   – show photos  
Stereo (Left photo)Ctrl+S   – display stereo window (first select the left photo and then the right one)  
Next pointCtrl+Q   – go to the next point  

Menu in the Points dialogue
 
Remove– remove a point (permanently) from calculations  
Freeze– exclude (temporarily) a point from calculations  
Show Photos– show the selected point on the photo  
Select From Map– show the selected point on the 3D image  
Next Point– go to the next point  
Next Point & display – go to the next point and display it  
Rename– change the name  




Relative Orientation

Since the Exterior Orientation module may be used for both relative and exterior orientation, to carry out a relative orientation only you should go to the Points dialogue, and select Relative only in the Parameters menu.
To carry out a relative orientation define Grubber points by selecting Options>Define Grubber Points (note! Grubber points are defined for the currently selected photo).

defGruber
The Define points dialogue appears where you should define points location for a given photo. Select Add Grubber Points in the Toolbar so that the defined points are displayed on the photo.
addGrubPoints
To make measurement indicate the desired point (click twice in the Points dialogue or display the Select point command and then select Set point in the dialogue) .
The selected point will be displayed both in a general view and in enlargement. Now you can precisely indicate the point in the enlargement window.
Grubber points are Tie Points of the photo. To orientate photos relatively just measure at least 5 points, and if you want the programme to calculate the matching errors (lateral parallax) select at least 6 points.


You can carry out the calculations in four different modes:
 
All photos in project– calculation of the whole project,  
Selected strip– calculation of a selected strip,  
Displayed photos– calculation of displayed photos,  
Selected model– calculation of a selected model  

dR lateral prallax will be the measurements result, given in [mm] in a model's scale.
You may also use just a part of data by removing a point permamently [Remove] or excluding it temporarily [Freeze]. To do it, select a given point, click the mouse's right button and select the remove or freeze option.



Exterior Orientation

To carry out an exterior (absolute) orientation introduce (unless they already exist) Control Points to the project using the Manager module, see - Controls

To introduce control points to the Exterior Orientation module, click Add Control Points in the Toolbar
addControlPoin
then a dialogue appears, where you can select desired (or all) control points. The points will be introduced to the Points dialogue, Control Points menu.
Carry out the points measurement as measurement of tie points, see Exterior Orintation – Relative Orientation, make sure you measure them also in height. To carry out the height measurement (placement in terrain) you should first point out the location of this point and then display a stereo window using the dialogue which is displayed after you click the mouse's right button - Stereo (Left photo) (or using Ctrl+S).
– see Exterior Orientation – Photos selection - Menu in the Points dialogue.
The DEPHOS system, Exterior Orientation module makes reduction of both longitudinal and lateral possible in the stereo window.
The longitudinal parallax is reduced when you turn the controller's "Z" wheel.
To reduce the lateral parallax turn the controller's "Z" wheel having the Shift button (on the keyboard) pressed.
After you deteremine the Tie Points and Control Points, start calculations.

There are four different modes to carry out calculations:
 
All photos in project– calculates the whole project,  
Selected strip– calculates a selected strip,  
Displayed photos– calculates dispalyed photos,  
Selected model– calculates a selected model.  
 
To carry out an exterior orientation deselect Relative only in the Points dialogue, Parameters menu and click Calculate. After that, in the Points dialogue, calculations results are displayed in a subsequent menu. In the Photos menu you can see a summary for all the photos (of all the points measured in subsequent photos).
You can introduce boundary error values to make results clearer, Parameters menu, Max Values – errors exceeding the boundary value will be displayed in red.
You can also see the error's scale on a 3D image. In the Parameters menu – Errors display scale you can define scales of displayed errors (as they might be invisible).
parameters
To display a 3D image click Display Map in Toolbars
displayMap
or click the mouse's right button (controller's button no.3) in the Points dialogue – Select From Map. The errors will be displayed as vectors towards deviations.
You can also use just a part of data for calculations, excluding a point temporarily - Freeze or permanently - Remove. To do it, indicate a given point, click the mouse's right button and choose either freeze or remove option.