The MRK File (Timestamp.MRK)
The MRK file is generated by DJI RTK Drones along with other files such as the PPKRAW.bin and the Rinex.obs files. These files are saved in the micro SD card together with your drone captures and are a requirement in processing your dataset using the PPK workflow provided by Skycatch Mining Solutions flown using Flight1 or other supported drone flight apps.
The timestamp.MRK contains a summary of the geotagging information required for PPK processing.
Tips for Identifying Good Quality Data for PPK Processing
This file contains text information, hence, it can be opened using Text editors. It is important to first check the following:
- The file is not empty or shows zeros. Both cases mean that the dataset is corrupted and PPK processing will not be possible.
- The number of lines matches the number of photos if the dataset comes from a single battery mission (for multi-battery missions there should be more than one MRK and other PPK files).
- The timestamps are indicated for each photo in GPS time composed by the week number (column 3), and the time in seconds (column 2). You can use this online calculator to transform GPS time into UTC time.
- The PPK workflow requires that the Edge1 or base observation time/ duration covers the mission duration. This means that the time to capture the first and last image should be within the base observation times. This is especially required for the last set of photos that belong to the altitude optimization leg.
- The RTK workflow adds the RTK status of each image. Check that the images show the status number "50", especially the last set of photos that belong to the altitude optimization leg. Alternate values shown below could also be indicated depending on the RTK streaming quality during the mission.
- 0-no positioning
- 16-point positioning mode
- 34-RTK floating point solution
- 50-RTK fixed solution
Note: More information can be seen individually in the EXIF metadata of each image. Please read through FAQ: What Is The EXIF Metadata?.