In the second stage of the 'edit project' wizard, you need to add the positions of the photos in the photogrammetric project. If you are editing an opened project, you can skip this 'Step 2'. However you still have the possibility to add new images to the project using the same type of file content. Keep in mind that if you want to import a new external orientation, you need to start a new project. In case of a new project, it is the purpose of this step to at least enter approximate coordinates for the projection centers of all images you wish to enter in the project. Imagename, X, Y and Z coordinate, Omega, Phi, Kappa are minimum obligatorily.



Two pre-defined options (Microdrone UAV and VisionMap data) are available to import EO data. If no MD or VisionMap data is available, select the last option.

• Convert and Import from UAV
  
• Convert and Import from VisionMap
  
• Specify EO file and Import
  
  
  

Prepare the processing of the UAV Imagery by:

• Copying all the original jpg images together from all flights that cover this actual project, in one folder.
• Copy all the md-Cockpit EO data files from every waypoint flight into the same folder. To be able to do so, the Microdrones MdCockpit software provides an EO datafile lookalike per flight, containing data from each position images are triggered on. Please extract these files using the MdCockpit application-menu “Export attitude parameter list for all photo tasks”, for each flight, like shown in the next image:
  
  
  
  
• Open each .sdf files for all the applicable flights using MdCockpit and put the exported files (txt format) in the same folder where you have copied all the images. This md-Cockpit exported EO data file contains :
  
  
  
  
  • photo-numbering
  • GPS time stamp and timecode
  • coördinates in lat/lon
  • GPS-height and height of the drone above groundlevel
  • camera attitude values called: roll, pitch and yaw
  • camera mount attitude values called Cam. servo

• Be sure that all images taken on the ground are deleted (photolist and directory). When no equal number of triggers from the drone and images are selected, next box will appear. Images can be ignored at the beginning or end of the flight.
  
  

After the preparation the processing can start, select the folder prepared in the previous preparation step. The procedure will now compare the images timestamps and the given EO data to:

• Check for missing images.
• Rename all the images starting from '1.jpg'.
• Transform all given Microdrones' EO data into the format (e.g. CRS) that Strabo needs. This file will will be placed automatically in the text field of the actual “Project Wizard” step 2.
  

Finally, tick on/off 'optimize strips'. Optimizing strips means that those images that are positioned to close to each other will be kept out of the EO (rule is based on half the mean distance of two project centra).

Strabo supports the Visionmap A3 imagery (External Link to Visionmap). In case of the use of the Visionmap A3 imagery some preparations should be taken before using the wizard.

The Visionmap A3 Imagery

The dialog besides shows how the image provider sets the imagery available. The dialog shows the contents of one image folder. One folder contains 1 file for each of the following extensions: .dat, .sup, .tif, .xml.

Keep in mind that OrbitGIS uses the CRS (Coordinate Reference System) supported by the Open Geospatial Consortium (OGC). The CRS mentioned in the Visionmap xml files has to have the same description. Please take first the necessary actions to set the same CRS description in the xml files if neceassary. see also http://www.epsg-registry.org/ for a check on the description of the CRS used in the xml files.

TIF to OMI format conversion

For reasons of fast access (multiresolution) and compression, the tif files should be converted to omi format. To perform the conversion, use the OrbitGIS Toolbox (Tools menu). This toolbox can be used to convert files that are located even in subfolders of the given source folder, as you can see in the next dialog. Even when the tif files are located in subfolders (or deeper) of the folder “original images”, all the tif files will be converted. The new omi file will be placed next to the corresponding tif file:

Move the TIF files

Move all the tif files to another separate folder using Microsoft Explorer file and copy functionalities. This can be done by searching for all the tif files starting from the “orginal images” directory, and afterwards moving all the found tif files to another folder.

Move the OMI files

Select in the same way all the omi files and move them out of their individual image folder, and put them one step higher: directly under the folder “original images”.

Keep in mind that there is no need to measure fiducial marks nor to set the distortion parameters. These parameters will be solved automatically using the metadata file. Be sure you added the right type 'visionmap' in the camera settings (project step 1).

After the preparation the processing can start, select the folder called “photoListStrabo.txt” prepared in the previous preparation step.

• Provide the directory containing the images: e.g. like ”…\original images” in the examples above.
• CRS used by the visionmap data: select your local project system.
• The directory where the data should be written: When pressing on the “Apply” button the software will inspect all the necessary Visionmap metadata files to create an EO (Exernal Oriëntation) datafile. Please set here the folder where you want to have this file saved to.
• CRS that should be used in the photolist file: select your local project system.

Finally, tick on/off 'optimize strips'. Optimizing strips means that those images that are positioned to close to each other will be kept out of the EO (rule is based on half the mean distance of two project centra).

1. You can either select the file containing the EO (External Orientation) data (a .txt file), or even create a new file on the fly. Select the appropriate .txt file containing EO (External Orientation) with either exact or approximate EO data for each image. Imagename, X, Y, Z, Omega, Phi, Kappa values (approximate values or measurements from flight registration equipment)
2. Indicate in which unit the angles are expressed. Choose between:
   • DEG (a straight corner is 90 degree).
   • GRAD (a straight corner is 100 degree).
3. Indicate the order of orientations. Choose between:
   • o p k (omega phi kappa).
   • p o k (phi omega kappa).
4. Finally, set the CRS (Coördinate Reference System) corresponding to the EO data of the imagery (more information, see Orbit CRS).

In the exceptional situation that you have no EO file available, you can create one on the fly. Start a text editor and enter approximate values for the images: (1) The name of the image. (2) Approximate projection center coordinates X and Y. These values can be GPS data, or they can be derived manually from a topographic map. (3) Z equal to the flying height or coming from GPS data. (4) Zero values for omega and phi. (5) Kappa must reflect the orientation of the camera taking into account that the West-East direction equals 0 degrees. This means that it is possible that the main flight direction is 0 degrees (flight in West-East direction) and at the same time kappa equals 180 degrees, in case that the x-axis of the camera coordinate system is East-West oriented.

Formatting the text file containing Exterior Orientation data

This text file must contain one line per photo containing the following data:

• A project wide unique photo name.
• X-Projection center approximation expressed in terrain system units.
• Y-Projection center approximation expressed in terrain system units.
• Z-Projection center approximation expressed in terrain system units.
• Omega approximation expressed in the selected angular unit (enter 0 when not known).
• Phi approximation expressed in the selected angular unit (enter 0 when not known).
• Kappa approximation expressed in the selected angular unit.
  Kappa can be e.g. 0 DEG for west-east flights and 180 DEG for east-west flights.
  The values entered here should reflect the camera orientation, these can be different than the strip oriëntation.
  Angles are expressed positive anti-clockwise.
• e.g. 2401 165211.012 546511.152 1240.122 0 0 180
• The data may be tab- or space-separated.