Table of Contents
Overview #
Learn how to use the BAAM.Tech PPK processing software.
Process #
- Create a new folder titled “Project Name”, save the aircraft PPK file and base files in separate folders (rover, base) within this new project folder.
- Create a folder named “raw” in your project folder, then save the collected images into the raw folder.
- You should have 3 folders at this point named: base, raw, rover.
- Open the BAAM.Tech processing software program.
- At the bottom there is a section to select what folder to save the project to, click “Browse” and select a folder to save the project in.
- Click “Load Rover”
- In the first box, enter the antenna height of the PPK Unit.
- For the Phantom 4 Pro: 0.2038m (make sure the measurement is in meters, not feet)
- If using another system, enter the antenna height phase center of camera to phase center of antenna.
- Enter the .SBP file from the aircraft. (You do not need the nav file below it, as the program will automatically do it for you.)
- Click load and confirm to convert to a Rinex file.
- Click “Load Base.”
- There are three options for entering the base location. If you read from the Rinex the location will not be as accurate, but still useful for testing data in the field.
- If you do not have your base location, you can use OPUS. The OPUS website will give you directions to follow if you are in need of a base file.
- Enter the base file in Rinex format. (Use our converter if using our base)
- The antenna: HXCGP500 NONE.
- Enter the antenna height from the phase center of the antenna to the ground.
- Enter your base location information in the follow boxes.
- Enter the base antenna height, this is the height from the phase center of the antenna to the ground.
- Select your base file.
- Click load base and confirm you want to convert to Rinex if using the BAAM.Tech Base.
- If you do not have your base location, you can use OPUS. The OPUS website will give you directions to follow if you are in need of a base file.
- Click Process.
- The software can take a while to to this step. The dial wheel will be spinning while it’s processing, the software is not frozen.
- Once that step is complete, go into the folder you saved the project to and open the event positions (.csv) created. You will want to make sure the Quality are all 1s (fix) or 2s (float). If they are 5, you either do not have the right base file, or you entered the location incorrectly.
- The majority should be 1s, but some 2s are acceptable.
- Think of the 1s like ground control points, if they are evenly spaced throughout the project then you are good, but if you have a full side of 2s you have a problem.
- Make sure the event numbers match up with the images taken during flight. If not, see where there are extra ground shots by looking at the altitude and copy/pasting the extra images in those locations.
- Once the data looks correct, close the even position file and click “Geotag Photos” at the top of the BAAM.Tech software window.
- Click “Browse Photo”. Enter the image folder location. Click “Browse Event Position Files”, then locate the event position file.
- Be very careful, a wrong input will throw off the project.
- Click “Geotag” and wait for the images to finish processing.
Geotag Accuracy #
One key item to make PPK data accurate is the geotag accuracy entered into the processing software. We walk you through Pix4D in the next section, but if you are using another processing program, it is critical the images with 1s (fixes) are set to 0.04m both horizontal and vertical accuracy. The 2s (floats) are set to 1.5m both horizontal and vertical accuracy. These values can be changed in the Event Position .csv file. Make these changes before you process your data in the BAAM.Tech software.
Quick Parameters #
- DJI Phantom 4 Pro Antenna Height: 0.2038m