This is documentation of an archived release.
For documentation on the current version, please check Knowledge Base.
For documentation on the current version, please check Knowledge Base.
Reports of post-flight process
Results: the interpretation of your (pre- and) postflight proces
results of preflight process
Once set up a preflight planning, a brief overview of your flightplan details can be seen here. More information can be found here.
results of postflight process
a brief overview of postflight details. Hoover on the text to see more details:
- number of photos
- number of strips
- average percentage of overlap in stereo models after processing
- average percentage of overlap between strips after processing
- number of stereo models
- number of strip models
- the calculated ground sample distance in cm
- the surface covered in ha
- the average flying height in m
- the number of calculated DEM points
a more extensive report of the postprocessing can be generated by clicking on the 'view report' button.
report
The 'Generate HTML report' creates a general report (that can be saved as *.pdf) with different figures (small and big) and facts ready for interpretation. The report and figures can be found in the 3_postflight folder structure of your saved project.
| project properties | general information about the project such as number of photos and camera name. |
|---|---|
| number of photos | number of photos used for postprocessing in project. This value can be different from the number of photos initially imported (e.g. surface covered by fence). |
| surface covered | surface covered in postprocessed project. This can be different from the surface in flightplan (e.g. surface covered by fence). Check the difference between pre- and post using the OrbitGIS tools. |
| average flying height | average flying height above sea-level |
| ground height | average ground height. This value was given by the user before import of the flight data. |
| average ground sample distance | average GSD (ground sample distance). This value is the result of the given camera specifications and average flying height. |
| percentage of overlap in stereo | estimated (preflight) and real (postflight) percentage of overlap in stereo. For generic users estimated percentage of overlap in stereo will be null. |
| percentage of overlap in strip | estimated (preflight) and real (postflight) percentage of overlap between strips. For generic users estimated percentage of overlap between strips will be null |
| # stereo models | number of stereo couples |
| # strip overlap models | number of overlap models between strips |
| multiple cameras | use of multiple cameras in postprocessing (option only exists in Strabo Software) |
| camera name | name of camera saved in camera database |
| self calibration | option in preferences about self-calibration on/off (self-calibration can only be used when postprocessing is succesfully finished. The self-calibration option will refine the result by optimizing the camera calibration. |
| camera focal length | The focal distance of the lens expressed in mm Wikipedia Focal Length (min-max of calibrated cam) |
| camera sensor long track | value equal to the number of pixels in the long track of the aerial flight (along the track) multiplied by the pixel size. |
| camera sensor cross track | value equal to the number of pixels in the cross track of the aerial flight multiplied by the pixel size. |
| camera pixel size | given in the calibration certificate of the camera and expressed in micron. |
| PP long track | the principal point of autocollimation along the flight direction (min-max of calibrated cam). These are the coordinates of the principal point found on the calibration certificate and are expressed in mm or pixels. In most cases these PP longtrack and crosstrack are expressed in PP X and PP Y whereas the X-axis is expressed according the orientation of the delivered images. When the images are rotated to fit in the flightplan, the PPX (and PPY) will be rotated as will be shown on the calibration report. Please read carefully the calibration report to interpret. Wikipedia Focal Point |
| PP cross track | the principal point of autocollimation across the flight direction (min-max of calibrated cam). These are the coordinates of the principal point found on the calibration certificate and are expressed in mm or pixels. In most cases these PP longtrack and crosstrack are expressed in PP X and PP Y whereas the X-axis is expressed according the orientation of the delivered images. When the images are rotated to fit in the flightplan, the PPX (and PPY) will be rotated as will be shown on the calibration report. Please read carefully the calibration report to interpret. Wikipedia Focal Point |
| K1, K2 | Radial distortion parameters, regarding the formulas of D.C. Brown (min-max of calibrated cam). Wikipedia Distortion |
| P1, P2, P3 | Radial distortion parameters, regarding the formulas of D.C. Brown (min-max of calibrated cam). Wikipedia Distortion |
| camera position according flight direction | Visual presentation of camera position according flight direction |
| Orientation Results | The absolute orientation of the camera at exposure time |
|---|---|
| omega, phi, and kappa | The maximum, minimum, average, and standard deviation of all orientation values (Wikipedia Aircraft principal axes). |
| Figure 1 | The representation of omega and phi at the projection centra. X-axis = omega. Y-axis = phi. |
| Figure 2 | The representation of kappa at the projection centra. |
| Overlap percentage | Overlap percentage of images in stereo/between strips. |
|---|---|
| est/real | estimated (before flight) and real (after flight) overlap percentage of images in stereo and between strips. |
| low/high | lowest and highest percentage overlap |
| Preferences bundle block adjustment | General information about the used preferences |
|---|---|
| reset omega and phi on import | If yes: omega and phi, or pitch and roll, values will be put on zero for import of the flight data. The given orientation (omega and phi values) coming from the drone will then be ignored. |
| number of detected features | low, standard, extensive, high extensive. the more detected features, the more matches but this will slow down the process. Default is standard value. |
| filter method (matching) | Fundamental matrix is the most general filter and default value. If there is only translation between your images, the translation filter can be selected (tick off the 'search for multiray' option). |
| search for multiray points | This multiray search will give your bundle more strength. |
| ratio for multiray matching | 0.2 - 0.7 : depending on the quality of images. This value can be very strict (0.2) or very weak (0.7). Values 0.3-0.4 are default. |
| activation of refine result technique | This refine technique will search for an extra number of matches after the bundle. This will slow down the process. |
| Results bundle block adjustment | Results bundle block adjustment |
|---|---|
| ground control point used | yes (option only exists in Strabo Software) |
| bba hard positioning | yes/no. Technique used for bundle (option only exists in Strabo Software) |
| number of control points | used/total |
| number of object points | number of object points |
| number of image point measurements | number of measurements of object points |
| average rays per object point | average number of measurements per object point |
| multiray points / total | number of multiray object points / total object points |
| unknowns | number of unknowns in bundle |
| degrees of freedom | This is the number of equations minus the number of unknowns. The number of parameters that may vary independently. |
| number of iterations | number of iterations during bundle adjustment |
| residual MSQE | standard deviation on the residual of the observations in mm |
| residual MSQE total | total sum of the residuals of the observations |
| observation residu average | standard deviation on the residual of the observations in micron |
| F-test | target = 1. The F-test is the ratio of Sigma Naught and the a priori standard deviation on the observations. On this value you can decide to accept the adjustment results or not. If F-test is too big, the software will warn you before starting to calculate the DSM and making the ortho. |
| a-priori standard deviation observations (sigma) | equal to the pixelsize of the camera (in mm) |
| a-posteriori standard deviation for all observations (sigma zero) | residual MSQE (in mm) |
| Connections between projection centra | Detailed information about the connections between projection centra. |
|---|---|
| total number of connections in stereo | total number |
| average number of stereo connections | number |
| minimum number of stereo connections | number |
| maximum number of stereo connections | number |
| standard deviation | |
| total number of connections between strips | total number |
| average number of strip connections | number |
| minimum number of strip connections | number |
| maximum number of strip connections | number |
| standard deviation | number |
| low number of connections between/in strips | Red color means low number of connections (see following tables about low number of connections in/between strips. Black color means strong connection. Click on figure to see more details. |
| Residues on object points: | distribution of X, Y, Z-residues on object points |
|---|---|
| distribution X-residues on objectpoints | largest values |
| distribution Y-residues on objectpoints | largest values |
| distribution Z-residues on objectpoints | largest values |
| Error on object points (resection): | Using the adjusted parameters, for each object point the resection is calculated. |
|---|---|
| average error | average error for all the resections in X, Y, Z, XY, and XYZ |
| standard deviation | standard deviation on all resections |
| Error on object points (bundle adjustment): | Error and standard deviation derived from the covariance matrix |
| average error |  |
| standard deviation |  |
| Error on ground control points: | To validate the adjustment, the image observations of the controlpoints are used to calculate the spatial intersection after the adjustment. These 3D coördinates are then compared with the given controlpoint coördinates. The difference vectors (xi, yi, zi) between given and recalculated controlpoints are used to provide an average and standard deviation. |
| average error |  |
| standard deviation | The standard deviation (sigma) is found by taking the square root of the average of the squared differences of the values from their average value.  |
| Results accuracy per ground control point | Results accuracy per ground control point. Click on figure to see more details about individual points. |
| Results digital elevation model | Results digital elevation model + figure |
|---|---|
| dem calculation | yes/no (option in preferences) |
| contour creation | yes/no (option in preferences) |
| preference dem density | low/medium/high (option in preferences). low = similar to object points; medium = extra matching; high = extra detection |
| regular grid activation | yes/no (option in preferences) |
| contour step size | contour step in m |
| Results orthophoto creation | Results orthophoto creation + figure. |
|---|---|
| orthophoto creation | yes/no (option in preferences) |
| orthophoto pixelsize | pixelsize used for mosaic creation in m |
| orthophoto image format | in orbit multiresolution image; use the conversion tool in OrbitGIS to convert image format |
| orthophoto image size | in kB |
| Process Allocation Time | Time needed for different processing tasks. |
|---|---|
| detection | 00h01m03s. If detection has not been executed time will be 00h00m00s. |
| matching | 00h01m03s. If matching has not been executed time will be 00h00m00s. |
| bundle adjustment | 00h01m03s. If bundle adjustment has not been executed time will be 00h00m00s. |
| dsm creation | 00h01m03s. If dsm creation has not been executed time will be 00h00m00s. |
| orthorectification | 00h01m03s. If orthorectification has not been executed time will be 00h00m00s. |
Last modified:: 2019/03/25 11:36