The standard processing workflow is the same for GCP, RTK and PPK drone data processing.
It utilizes high quality processing methods that are specific to each vertical and includes automated GCP tagging, full quality check & the option of adding advanced analytics to your survey.
While not recommended, users may also process data without control, however, as GPS is typically limited to accuracy no better than ~1-5m, producing results substantially shifted from reality which will not align with any past or future surveys.
Processing GCP, PPK or RTK data requires the following steps:
- Image Import
- Select between "Self-Service" or "Advanced" Photogrammetry
- Add Ground Control Points
- Assign Horizontal and Vertical Coordinate Reference System (CRS)
- Upload images
- Request for Analytics (if desired)
Note: for processing without control skip step 3
Step1 - Image Import
Login to your account.
Select the desired project.
On the bottom left, press Upload, click New, then Upload a new image dataset.
Press on browse files, to locate the images saved on your computer. Press Open, or drag the files into the upload area and then click Next.
Select Flight Date - The system will automatically read the exif data, geo-locate the files and select the appropriate project and flight date.
Flight Name can be used to identify the survey by something other than the flight date, such as a particular AOI (stockpile area, west pit, etc.)
If you have more flight images from the same survey, press on "+ Add more" to add the remaining images.
If your images are not geotagged, click on Edit Locations to upload the flight Metadata in .CSV or .TXT format to be used for geolocating the images.
The polygon boundary surrounding the image markers may be adjusted in order to exclude certain images from processing.
Note: The green polygon represents the existing project area to ensure your images are in the project zone boundary.
Once finished with defining what images should be processed click Next.
There are two options available under "Execution of Photogrammetry". Click Edit settings to define the options.
- Basic processing engine will be used resulting in quicker processing time. Using Basic Processing may have reduced data quality and accuracy.
- User will be responsible for identifying their own GCPs if applicable.
- Delair will not perform a quality check of the results before publication of the data.
Automated and Verified processing resulting highest standard of quality and most accurate results available.
If any advanced analytics are to be done on the dataset this method is required.
Unless otherwise specified, this is the setting that should most often be used.
Delair will perform a quality check of the results.
Ground Control Points
In order to ensure the highest accuracy processing possible, even in RTK/PPK situations, one or more GCPs or Checkpoints (For RTK and PPK) are recommended as it can greatly increase accuracy.
To add a GCP file, click on Add ground control points (GCP) and drag & drop your file or click browse to locate it on your device.
The file should be in .CSV or .TXT format, no header row and only delimited with a comma. The file must be in the following format:
- Name/reference of the GCP
- X coordinate
- Y coordinate
- Z value
- X/Y accuracy (optional)
- Z accuracy (optional)
Once the GCP file has been uploaded, verify that the x/y/z columns appear in the correct order.
Press on Edit CRS to select the projection of the GCPs.
*The GCP CRS will take into consideration the CRS selected at the project creation. It must be selected. If it is not the same, reconvert the GCP file to the same Project CRS and then re-upload the GCP file.
If the selected CRS and the GCP file coordinate system match, the GCPs should appear on the map as orange dots within the survey boundary.
If nothing appears, then it may be possible that the CRS is incorrect or the X and Y coordinates are reversed.
To retry, deselect Add ground control points (GCP), fix the file, and then select Add ground control points (GCP) and try again.
Click on Launch Upload on the bottom right of the screen, then click finish.
You will be taken to the homepage where the project has been created and the images will be uploaded to. If you are using a laptop, ensure that it is plugged into power to prevent the battery from running down and interrupting the upload ; Do not refresh or close the page until the upload has completely finished.
If necessary the upload can be temporarily paused and resumed by utilizing the Pause button on the Projects page .