Prepare a GCP File for your site

To upload a GCP rectified dataset, a GCP csv file needs to be uploaded along with the drone images. When you toggle Do you have GCP data, there is a tool to help you prepare the GCP File template, you can follow the steps below to get your customized GCP File template for your site. You can use the same GCP template on the same site as long as the configuration in your GPS device remains unchanged. For customers who use our old template, you can also create a new one with these steps. In this way, you don't need to do extra units conversions between feet and meters after specifying it for easting/northing.

1. If your coordinates are longitude and latitude, choose Latitude and Longitude (WGS84), else choose EPSG code and input the code. You can always contact our support team to get the correct EPSG code.

2. Select the elevation units, it can be meter, feet, or US survey feet. It should be the same as what is configured in your GPS device.

3. Select the Easting/Northing Units. If you select Latitude and Longitude (WGS84) at step 1, you should choose From EPSG, else it should also be the same as what is configured in your GPS device.

4. Click Download Our GCP File Template to download the template CSV file.

5. In the image above, I created a template with EPSG:32616, elevation unit usft, and easting/northing unit usft. You can use any spreadsheet viewer to edit it (Excel, Google Sheets, etc.). As you can see below, cell A1 is the EPSG code, the second row gives the headers. GCP ID is the name for each ground control point, Longitude/Easting<usft> is the column for X value, Latitude/Northing<usft> is the column for Y value, Elevation<usft> is the column for Z value. "<>" is used to indicate the units for each column. 

6. You can then move the exported coordinates to the template, please make sure to move the easting, northing values to their corresponding column. Note that we need at least 5 GCP points to have accurate rectifiction.

7. At last, save the file in CSV format, and you can move forward to upload it.

Further reading: How to rectify your dataset with GCP points