Basic system
The network is based on the AllSky7 systems manufactured by Mike Hankey. Details about the systems were published in a paper at Meteoroids 2020 conference.
Each system contains seven highly sensitive NetSurveillance NVT cameras with the SONY STARVIS IMX291 CMOS Sensor and a 4 mm f/1.0 lens. Five of them are horizonally oriented at an altitude of about 25°, camera six and seven point in northern and southern direction at an altitude of about 70° All together they cover the full sky down to the horizon.
Each camera has a field of view of about 45x80°. The cameras are recording at 25 fps and reach a limiting magnitude of about 4 mag. Maximum resolution is 25 pixel/°.
Beside the cameras, the dome contains a power supply and an ethernet switch for each camera. Each camera has a black paper baffle. The dome is painted from the inside with two color layers - silver outside and pale black inside. That reduces internal reflections and the thermal influx.
Power is supplied via Power-over-Ethernet (PoE), so that the whole system needs just one CAT-6 Ethernet cable to connect it to base computer. The computer is a barebone Mini PC running Ubuntu and the AllSky7 software by Mike Hankey, which is continuously improved. Each camera provides an SD (704x576 pixel) and HD (1920x1080 pixel) video stream which are recorded by the Mini PC and analysed asynchronously.
The camera is recording meteors and fireballs 24/7, but at the moment only the nighttime recordings are automatically analysed. About 5.000 meteors are recorded per year under typical central European conditions.
The software provided by Mike Hankey covers all aspects of the measurement of fireballs. It allows to sort out false detections from the daily meteor stack, to measure the position of fireballs in single video frames, to identify reference stars and do the astrometry and photometry of the recording, and to combine the observation with data from other camera stations to calculate trajectories and orbits. The software comes free of charge for all members of the AllSky7 Firebal Network (community license). All software functions are shown in a short advertising film.
AllSky7+
In 2022 we upgraded the system to AllSky7+ by adding an 8th camera with a 1.13mm fisheye lens on top. This camera records the full sky at once and provides improved photometry and astrometry of particularly bright fireballs.
AllSky7+ HS
In 2024 we switched to an high sensitivity (HS) edition by replacing the Sony IMX291-based with an IMX307-based camera. This sensor reaches higher sensitivity by improved noise reduction and yields superior performance in particular for stationary objects (e.g. stars, aurorae). This can be seen best during twilight, when the images still look like day-time recordings.
AS7 Sensor Board
Starting from 2025, new system are equipped with a AS7 Sensor Board (AllSky7+ HS SB). This boards provides precise timing (1PPS) and geo-location, but also temperature and humidity inside and outside the dome. The sensor board comes optionally with a relay that can control a fan, heating device or cooling device, or any other system added by the camera operator, based on the climate inside and outside the dome. The sensor board provides additional digital ports for custom extensions.
AS7 Health Checker
The AS7 Health Checker is an add-on for camera operators to monitor the state of their systems in real-time. It offers two different modi. In local mode, which is designed for expeditions and environments without Internet connectivity, the health checker connects via WiFi directly to the Mini PC. In global mode, it connects via Internet to the computer. AS7 Health Checker reads and displays the system state and issues an alarm in case of serious problems. The device can be customized by the camera operators.
