GCP information is usually stored in simple text file formats such as .txt and .csv. These files may come from the professional surveying station, or they can be created by the user.
To create a GCP text file one must follow a simple column structure. In each row of text data should contain the same structure. The most convenient and simple line structure for the GCP data would be: GCP label-space-latitude-space-longitude-space-altitude. Using this structure we can create a text document using notepad that should look like this.
Coordinates can be entered in any coordinate system, and the coordinate system can be selected while importing the file.