Well-Known Text (WKT) in PIX4Dcatch

Well-Known Text (WKT) is a text string that defines all parameters of a coordinate reference system (CRS). A WKT string is commonly stored in a projection file (.prj) and can be opened in any text editor.

PIX4Dcatch supports importing WKT files (WTK1 and WTK2), making it possible to define and use a custom CRS that is not available in the built-in catalog, including custom site localization files. For information on Site Localization files, click here.

Formatting WKT Files

WKT files must follow the OGC Well-Known Text for Coordinate Reference Systems
standard and define a projected CRS. Ensure the file is properly structured so PIX4Dcatch can recognize and apply the coordinate system.

Requirements for WKT Files

A WKT file must meet the following criteria:

• Define a projected Coordinate Reference System.
• Include the appropriate EPSG codes.
• If a Geoid Model is included, it must be recognized by the PIX4D database.
• Cannot contain EPSG vertical references with Geoid Height.

How it works

A WKT file can be imported at three different stages in PIX4Dcatch: 

• When creating a new point collection in Survey mode.
• During upload to PIX4Dcloud.
• In the project settings.
  
  

New point Collection 

When starting a new point collection, the output CRS can be selected from the catalog or imported from a WKT file.

To insert a WKT when creating a new point collection, follow these steps:

1. Open Survey.
2. Tap New point collection.
3. Create New point collection.
   
   
4. Select Import Coordinate System
5. Tap Import File and select the WKT file.
6. The file will be shown as imported Coordinate System
7. Tap Select

Using WKT During Project Upload

By default, PIX4Dcatch uses the automatically detected CRS during upload. This can be overridden by importing a WKT file.

To use the WKT when uploading to PIX4Dcloud, follow these steps:

     1.In the upload screen for cloud processing options, tap Autodetected.

     2.Tap Import coordinate system.

     3. Tap Import file and select the WKT file.

     4. The file will be shown as imported Coordinate System.

     5. Tap Select

     

Using WKT in Project Settings

The CRS can also be updated in project settings before cloud processing.

To use the WKT in the project settings, follow these steps:

1. Open Project settings.
2. Tap Autodetected under the CRS section.
3. Tap Import coordinate system.
4. Tap Import file and select the WKT file.
   
   

5. The file will be shown as imported Coordinate System.

6. Tap Select

If the import is successful, the WKT file name will replace “Autodetected.”