WebSDR is a Software Defined Radio receiver connected to the internet that allows many listeners to listen at the same time and tune in individually.
The CAMRAS WebSDR stream can be listened to at http://websdr.camras.nl:8901 (opens in a new window or tab).
For webSDR reception JAVA must be installed on the computer or the browser must support HTML5. With some web browsers, it is necessary to manually grant the website permission to pass on audio.
The CAMRAS WebSDR stream also works on most tablets and mobile phones and can be listened to at http://websdr.camras.nl:8901/m.html (opens in new window or tab) if necessary.
When logging in, a cookie is placed with which name (not mandatory) and settings are retained.
The webSDR offers you, via the separate frequency bands, live reception using the Dwingeloo telescope:
- The radio telescope receives so-called “Earth Moon Earth” (EME) moon echoes at a frequency of 432 MHz (70 cm wavelength).
- The radio telescope receives moonlanders, moon orbiting satellites and LEO amateur satellites (AMSAT) at a frequency of 437 MHz (70 cm wavelenght)
- The radio telescope receives so-called “Earth Moon Earth” (EME) moon echoes at a frequency of 1296 MHz (23 cm wavelength).
When the telescope does not actually follow the moon, it is still possible to receive signals from radio amateurs on the aforementioned frequencies. This is due to reception via so-called “side lobes” of the dish and via atmospheric reflections.
If there is no live stream, the CAMRAS WebSDR will play recordings from:
- The Echoes of Apollo project made during the EME session with the 300 meter Arecibo radio telescope at a frequency of 432 MHz (70 cm wavelength). This image was taken on April 17, 2010 at around 19:00 UTC.
- The Echoes of Apollo project 2009. This image contains a QSO between PI9CAM (the call sign of the Dwingeloo radio telescope) and HB9MOON at a frequency of 1296 MHz (23 cm wavelength).
You can also listen to satellites and meteor echoes on the CAMRAS WebSDR stream:
- On the 2-meter band receiver, echoes from the GRAVES radar system in France can be received. You can think of the echoes of meteors, but there are also airplanes, satellites and sometimes echoes from the Moon. CAMRAS uses a 144 MHz Yagi antenna with 4 elements facing south, 13 meters above the ground, in the radio interference-free zone near the radio telescope.
- Via the other 2-meter band receiver, in addition to the comnunication between radio amateurs, the astronauts in the ISS, amateur satellites can also be received.
- With the “meteo” receiver, 137 MHz NOAA and METEOR MN2 weather satellites and aircraft communications can be received. CAMRAS uses the same 2-meter band Yagi antenna for this, also in the radio interference-free zone near the radio telescope.
- With the “aero” receiver, among other things, the communication of (glider) planes with the nearby Hoogeveen airport (EHHO) can be received. For this, CAMRAS uses the aforementioned 2-meter band Yagi antenna, also in the radio interference-free zone near the radio telescope.
- With the 4-meter band receiver, among other things, propagation beacons and radio amateurs can be received. CAMRAS uses a 4-element 70 MHz Yagi antenna that points to the south, 11 meters high, also in the radio interference-free zone near the radio telescope.
- With the 6-meter band receiver, among other things, the echoes of the Belgian meteor beacons at Dourbes and Ypres and the English GB3MBA meteor beacon can be received. CAMRAS uses a 3-element 50 MHz Yagi antenna that points to the South West, 9 meters high, also in the radio interference-free zone near the radio telescope.
- On the “Jove” receiver, decametric radio waves from the planet Jupiter and one of its moons Io can be received, only if the ionosphere is transparent to these waves from space. Otherwise, only terrestrial stations can be received. The antenna is a 20 MHz double dipole “phased array” with an elevation of 40 degrees, directed towards the south, on 4.9 meter high masts, also in the interference-free zone near the radio telescope.
This WebSDR was developed for CAMRAS by Pieter Tjerk de Boer (PA3FWM) Pieter Tjerk de Boer (PA3FWM) and the software now has many users. More information at: www.websdr.org.
