It is possible to capture and mark Ground Control Points (GCPs) in PIX4Dcatch projects. After the capture, select a point collection to start the process, allowing for PIX4Dcatch projects to achieve higher absolute accuracies that GCPs provide.
IN THIS ARTICLE
Obtain GCP Collection
Measure GCPs in a project
Import GCPs to PIX4Dcatch
Mark GCPs in PIX4Dcatch
Process projects with GCPs
Processing PIX4Dcatch projects with GCPs on PIX4Dcloud / PIX4Dcloud Advanced
Processing PIX4Dcatch projects with GCP marks in PIX4Dmatic
GCPs are stored in a Point Collection with corresponding coordinates.
PIX4Dcatch with the RTK rover can also be used to measure and collect GCPs. For more information: How to measure single points(GCPs) - PIX4Dcatch RTK.
PIX4Dcatch is also capable of importing GCP coordinates into an existing Collection. If the desired Collection does not exist yet, please create it first. Then there is an option to Import Points. Please note that coordinates have to be in the same coordinates system as the Collection itself. For input format, please refer here: Tie points (GCPs, CPs) import format - PIX4Dmatic
Open the Project management dialog.
- Select the project.
Open the Point Collection selection dialog you want to use as GCPs.
- Close the dialog; the GCP icon will turn blue, selected Collection will be displayed. Now, the Mark points is also available.
- Select Mark points.
- Select the GCP from the list to mark.
Mark GCP on an image with a single tap. Hold tapping a bit longer to open the magnifier for more accurate marking. To expand an image or delete a marking, tap the 3 dots at the top right of each image.
- Mark the GCP at least on two images.
- GCPs will be shown on the map; marked images will be displayed in green on the map.
- Tap Save.
- Select and mark additional GCPs for the project as before.
There are two main ways to process data obtained with PIX4Dcatch.and also to use the maximum zoom level to be able to mark the GCP at the pixel size level
The most automated way to process is to upload data from PIX4Dcatch to PIX4Dcloud. This will include marked GCPs in the project and send a notification once the processing is ready and all requested results are available.
- Export the project files from PIX4Dcatch. How to export PIX4Dcatch projects (iOS/Android) for more information.
- Create a New Project in PIX4Dmatic with the data.
- Process locally in PIX4Dmatic and eventually upload the results to PIX4Dsurvey or PIX4Dcloud, if needed. How to import a PIX4Dmatic project into PIX4Dsurvey, or How to upload or replace results to PIX4Dcloud for more information.