Ground Truth System
During experiments, ground truth data is required to compare the perceived performance of the spacecraft to its actual performance. For this reason, a PhaseSpace Impulse X2E camera system was purchased. It consists of 10 cameras that are positioned around the lab, facing the granite table. All 10 cameras are connected to a provided server that processes the output from the 10 cameras, and returns the resolved position and attitude of the spacecraft platforms, in real time, at up to 960Hz. It is important to have multiple cameras covering each section of the table. A picture of the lab is shown in the Figure below, where the black PhaseSpace cameras are visible attached to the walls. The camera with the antenna in the back left corner communicates with the Microdrivers (battery packs) that turn on and off the LEDs mounted on the platforms.
The Microdrivers, shown below, are turned on by pressing the white button. To turn off a Microdriver, press and hold the white button until the light no longer blinks (about 10 seconds).
The microdrivers are assigned to each platform through software. The ID numbers associated with each platform are shown in the following Table
| Platform | PhaseSpace ID |
|---|---|
| RED | 1 |
| BLACK | 2 |
| Drone | 3 |
Any Microdriver can be used for any platform, as long as its ID is set to the correct one for that platform. To set the ID of any Microdriver, follow this guide. This way, if a Microdriver fails, another one can easily take its place by simply changing the software ID. This guide also specifies how to pair a new Microdriver to the system.
Once the cameras are installed and the microdrivers are paired, the system needs to be calibrated. This is done by moving an object with a known size through the field of view of all the cameras. A wand is provided by PhaseSpace and is used to calibrate and align the camera system.
Reach out to Phasespace support if you have any questions.