News
[2017-11-22]Today we start hunting the Alpha Monocerotids in BRAMS data with the help of Radio Meteor Zoo users
Our next Radio Meteor Zoo objective is to observe activity from a "minor" meteor shower called the Alpha Monocerotids. The parent body at the origin of the shower is not known but is assumed to be a long-period comet. The shower was visually observed in 1925, 1935, 1985 and 1995, each time around November 21. Every time, the period of activity was very short (a few tens of minutes to a few hours). In 1995, it produced a spectacular outburst with around 200 meteors observed in half an hour.
Some models suggest that Earth will cross a dust trail on November 21, around 21h UT and we will investigate this with our radio observations from the BRAMS network. In 1995, forward scatter radio observations clearly detected the Alpha Monocerotids above the sporadic background. So we are confident that, if there is an outburst, we will be able to detect it.
Since the entry speed of these meteors is estimated at 65 km/s, we expect to have a lot of complex meteor echoes, which justifies the use of the Radio Meteor Zoo to detect them. You are cordially invited to help us processing the observations from November 22 9h UT onwards.
We look forward to seeing as many Radio Meteor Zoo users as possible to help us hunt the Alpha Monocerotids!
For more information, please check this link on the Radio Meteor Zoo forum or this link on the IMO website.
Some models suggest that Earth will cross a dust trail on November 21, around 21h UT and we will investigate this with our radio observations from the BRAMS network. In 1995, forward scatter radio observations clearly detected the Alpha Monocerotids above the sporadic background. So we are confident that, if there is an outburst, we will be able to detect it.
Since the entry speed of these meteors is estimated at 65 km/s, we expect to have a lot of complex meteor echoes, which justifies the use of the Radio Meteor Zoo to detect them. You are cordially invited to help us processing the observations from November 22 9h UT onwards.
We look forward to seeing as many Radio Meteor Zoo users as possible to help us hunt the Alpha Monocerotids!
For more information, please check this link on the Radio Meteor Zoo forum or this link on the IMO website.
[2017-11-21]Last week-end two bright fireballs were observed above/nearby Belgium and BRAMS clearly detected them.
The first one was on 17 November at 00:27 UT. Below are spectrograms from BEHOVE and BELIEG. The meteor echo was so bright that it actually smears out most of the other signals in the images.
The second one was on 19 November at 02:29 UT. Below are spectrograms from BEHUMA and BEOPHA. The meteor echo is very long and split on two consecutive spectrograms.
It was observed with video cameras above Netherlands. See this link for some spectacular images.
The second one was on 19 November at 02:29 UT. Below are spectrograms from BEHUMA and BEOPHA. The meteor echo is very long and split on two consecutive spectrograms.
It was observed with video cameras above Netherlands. See this link for some spectacular images.
[2017-10-21]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.
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.
[2017-10-20]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.
[2017-10-16]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
[2017-09-27]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:
From 21 to 24 September, the International Meteor Conference 2017 was organized in Petnica, Serbia. The following presentations were 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
[2017-08-30]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.
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.
[2017-08-21]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.
[2017-08-16]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.
Last night, the very first detection of a fireball occured, also detected by the camera located at ESTEC in Noordwijk.
[2017-08-11]The Radio Meteor Zoo (and the Perseids) in the Flamish press
[2017-08-11]The Perseids are back and we need your help for the Radio Meteor Zoo
The Perseids are already coming back! The maximum of activity of the meteor shower is planned for 12-13 of August. The full Moon is on 7 August so conditions will not be optimal for visual observations. In this case radio observations are even more important.
This year we would like to be able to produce an activity curve for one station by August 15. This is very challenging and for that we will need the help of many of you!
One day of data consists of approximately 300 images. Each of them needs to be analyzed by 10 different users. We will provide images from 11 to 13 of August, one day at a time. So to obtain an activity curve on August 15, we will need about 9000 classifications in 3 days. If e.g. 1000 users are participating, that will be 9 classifications per user on average, or 3 images classified per day. Of course the more users the better!
Data will be released on 12, 13 and 14 of August as we need to collect and prepare them for upload to the RMZ website. Meanwhile you can also help us by analyzing data from the same station obtained on 22 and 23 of July, during days when the Perseids were not active at all. If these data are fully processed before the meteor shower, we will then be able to also subtract the background from the total activity. That is the ultimate goal for August 15.
We hope to "see" as many of you as possible on August 12-14 and that between two classifications, you might also be able to spot a few shooting stars at your location.
Get involved again at the Radio Meteor Zoo
Thank you in advance!
This year we would like to be able to produce an activity curve for one station by August 15. This is very challenging and for that we will need the help of many of you!
One day of data consists of approximately 300 images. Each of them needs to be analyzed by 10 different users. We will provide images from 11 to 13 of August, one day at a time. So to obtain an activity curve on August 15, we will need about 9000 classifications in 3 days. If e.g. 1000 users are participating, that will be 9 classifications per user on average, or 3 images classified per day. Of course the more users the better!
Data will be released on 12, 13 and 14 of August as we need to collect and prepare them for upload to the RMZ website. Meanwhile you can also help us by analyzing data from the same station obtained on 22 and 23 of July, during days when the Perseids were not active at all. If these data are fully processed before the meteor shower, we will then be able to also subtract the background from the total activity. That is the ultimate goal for August 15.
We hope to "see" as many of you as possible on August 12-14 and that between two classifications, you might also be able to spot a few shooting stars at your location.
Get involved again at the Radio Meteor Zoo
Thank you in advance!
[2017-05-08]Internal seminar on the Radio Meteor Zoo
Last Friday, Hervé Lamy gave an internal seminar about the Radio Meteor Zoo. The presentation included the reasons why we started a Citizen Science project, how we collaborated with Zooniverse, how we deal with individual contributions from Zooniverse users and finally some preliminary results. The presentation is available here.