video fireball observatory

This project was a proof of concept relating to the Desert Fireball Network, a research program “studying the formation of the solar system through the study of meteorites, fireballs and their pre-Earth orbits”. The program currently uses a network of observatories based around a DSLR cameras fitted with a fisheye lens and the proof of concept was around the feasibility and cost effectiveness o f transitioning to a video camera based solution.

One of the key outcomes is that while it is possible to come close to achieving the requirements (particularly sensitivity) of the existing observatories with a single video camera (at around 30 fps), the price is approximately an order of magnitude higher than the current solution. There is however an alternative which can be achieved for approximately twice the price of the existing solution, can achieve higher sensitivity and a much higher frame rate (exceeding 50 fps): using an array of cameras.

After extensive investigation of camera and lens combinations which could (on papaer) meet the hardware requirements of the observatory, one single camera system and one multi-camera system were further developed and compared. The single camera system used a Ximea CB200MG-CM camera body (utilising the CMOSIS 20MP sensor) paired with a Samyang CS II fish eye lens and the multi camera system with 6 ZWO ASI178MM cameras with Fujinon DV2.2X4.1SR4A-SA2L lens aligned on intersecting planes which form a pentagonal pyramidal frustum. CAD designs of the camera and lens hardware from both options can be seen in Figure 1.

Figure 1: Single camera with fish eye lens (Ximea CB200MG-CM with Samyang CS II lens) and 6-camera-array (ZWO ASI178MM with Fujinon DV2.2X4.1SR4A-SA2L lens)

The result in both cases is the ability to film high resolution video with a hemispherical field of view. Based on the higher frame rate, sensitivity, parts availability and lower cost of the 6-camera alternative, test units were procured and the solution was developed further, including software development, detailed sensitivity testing and detailed system design. Software development was done using the ZWO ASI camera SDK and Open CV3. The code for basic camera control and configuration including synchronised video recording or image capture with up to 6 ASI series cameras can be found at my GitHub here (including installation instructions).A prototype mount, circuit for lens control and the camera was tested to ensure that it met the design criteria. Check out the photos and graphics below.