BRAMS Newsfeed
A fireball above Belgium detected by BRAMS and by FRIPON optical camera /radio antenna
On 20 October 2017 around 00:37 UT, a fireball passed above Belgium and Netherlands. It was clearly detected by the FRIPON cameras in Brussels and Noordwijk. 
It was clearly detected by all BRAMS stations as a bright overdense meteor echo. Here are a few examples obtained at BELIEG, BEOPHA, BEUCCL, BEHAAC, BEOTTI and BEHOVE. Note that it was so bright that the noise is barely visible on most spectrograms and that some saturation sometimes occurs. 
It was also detected by the recently added FRIPON radio antenna listening to the military radar located in Graves, near Dijon, and emitting at approximately 143 MHz. A trail echo is clearly visible for at least 6 seconds. No head echo was detected for this case. 
New FRIPON radio antenna in Uccle
On 19 October 2017, we have installed a radio antenna on the roof of the institute in Uccle, as part of the FRIPON-radio project. 
Annual BRAMS meeting at MIRA public observatory on 14/10/2017
On 14 October 2017, the people at MIRA Observatory have welcomed us again for the BRAMS annual meeting 2017. The following presentations were given :
- Status of the BRAMS network - H. Lamy
- New automatic detection method : description and some results - H. Lamy
- First results with the BRAMS interferometer & calibration tests - H. Lamy
- The Radio Meteor Zoo: searching for meteors in BRAMS radio observations - H. Lamy
- CAMS coverage for BRAMS meteor echoes - P. Roggemans
- Status of the radio and optical FRIPON network - Jean-Louis Rault
- FRIPON radio - Jean-Louis Rault
Presentations given at the EPSC 2017 and IMC 2017 international conferences
From 17 to 22 September, the European Planetary Science Congress was organized in Riga, Latvia. The following presentation was given:
- The Radio Meteor Zoo: searching for meteors in BRAMS radio observations was given by H. Lamy. PDF version
From 21 to 24 September, the International Meteor Conference 2017 was organized in Petnica, Serbia. The following presentations were given :
- The Radio Meteor Zoo: involving citizen scientists in radio meteor research by Stijn Calders. PDF version
- Using a small phased array for meteor observations by Antonio Martinez Picar
- Observations of the Geminids 2016 with the BRAMS radio interferometer by Hervé Lamy. PDF version
- Overview of major shower observations 2016-2017 by the BRAMS network by Cis Verbeeck. PDF version
Calibration of the radio interferometer in Humain
On 29 August we went to Humain to measure very accurately the electric length of the RF cables from the antennas to the receivers. Since the interferometer works by measuring phase differences between antennas, systematic errors may occur due to the fact that the radio waves still need to travel along the cables. In these cables, the speed of propagation is only 2/3 of the speed of light and the wavelength is then of 4 meters. An error in the length of one cable of 20 cm would then introduce a systematic error on the phase of (20/400)*360 = 18 degrees. Since the antennas are located at different distances to the location with all receivers the length of the cables are naturally different. To compensate we have added an extra-length of cable at the bottom of the antennas when necessary. However, the accuracy cannot be better than 10-20 cm and therefore we needed to make these tests. The electric length of the cables is basically measured by generating a square signal, taking its approximate derivative which has a very fast rising flank. This signal is sent into the cable, reflected at the end, and we measure the delay needed to travel the cable (twice) by detecting the same (delayed) rising flank. This was done using a counter, a generator and two directional couplers. The principle is sketched below. 
By repeating the measure on a very large number of flanks and integrating the results, the accuracy on the average delay is of the order of 4 picoseconds. The time delays measured between the rising flanks of the direct and reflected signals are typically of 250-252 nanoseconds. 250 nanoseconds corresponds to a length of around 50 meters. What matters are the small differences between the time delays measured between 2 antennas. These are systematic errors on phase delays that we need to take into account.
New fireball detected by the FRIPON camera in Uccle
On 19 August, another fireball was detected by the FRIPON network including the camera in Uccle. 
First fireball detected by the FRIPON camera in Uccle
As part of the METRO project and an on-going international collaboration with IMCCE, we have installed a FRIPON camera on the roof of the institute in Uccle. 
Last night, the very first detection of a fireball occured, also detected by the camera located at ESTEC in Noordwijk. 
