IMO Commissions

Visual

A standard observing method for visual meteor observers has been used since the late 1980s which is both comprehensive for serious analyses of meteor showers and simple enough to be employed by everybody at any place of the world. The IMO Handbook for Meteor Observers describes the method in detail. Every meteor astronomer is invited to make use of the method in order to obtain comparable results, and to send in her or his data to the global database maintained by the IMO.

The main objectives of the IMO's visual observing program are:

• to study the structure of major meteor showers by means of hourly rate profiles and magnitude distributions;
• to study the physical parameters of meteoroid streams such as the flux density of particles in space and their mass distribution;
• to monitor the minor-shower activity by plotting meteors into star charts for a more objective association of meteors with weakly active radiants.
• to monitor meteor activity for unexpected events throughout the year;
• to study the sporadic background, following the annual activity.

All observational data are stored in the Visual Meteor Database (VMDB). This central archive of amateur visual observations is open to:

• analyses of activity profiles, population index profiles, flux density profiles and mass index profiles;
• IMO members and professional meteor astronomers, for access to its data.

For further information and questions about visual work within the IMO, the Visual Commission will gladly assist you.

Visual Commission Director: Rainer Arlt, Friedenstr. 5, D-14109 Berlin, Germany.

Video

Video Observation is the youngest and one of the most advanced observing techniques in meteor science. Professional astronomers started to use video equipment at the beginning of the seventies, among amateurs the Japanese (1986) and Dutch (1987) observers have been the first using this technology. By now, video observations of amateurs have reached a semi-professional level as appreciated by the corresponding IAU Commission 22. In fact, regular observations of meteor shower with automatic video systems have started in Germany in 1999, and the number of participating observers is growing ever since. To actively support further developments, a Video Commission of IMO was founded after a one year preparation phase at the 1997 IMC in Petnica. As a basis for the work of the commission acts a paper that was published in WGN at that time.

Video Commission Director: Sirko Molau, Abenstalstr. 13b, 84072 Seysdorf, Germany.

Photo

Photographic work is organized to encourage amateurs to photograph as many meteor trails as possible, provided that exposure data are accurately reported and made available for astrometric calculations. The main objectives of the IMO's photographic program are:

• collecting photographed meteor trails for astrometric reduction in order to obtain a large enough database to study by statistical methods the distribution of accurately measured meteor trails;
• setting up double station programs in order to obtain meteor heights and trajectories in the atmosphere, to accurately determine the radiant position of individual meteors and their heliocentric orbits;
• conducting meteor stream searches using the available heliocentric orbits and radiant positions, in order to confirm or to discover so-called minor showers that are hard or impossible to detect by means of other observations (their activity being embedded in the sporadic background);
• supporting photographic fireball patrols, as well as collecting and analyzing fireball data through the IMO's FIreball DAta Center (FIDAC)
• creating and/or expanding all-sky camera networks.

Please report all fireball observations to FIDAC, now the global center for collecting fireball reports.

More information can be obtained from the IMO Photographic Commission.

Photographic Commission Director: Currently vacant. For general information, technical questions or requests for reduction of double station observations you can contact: Marc de Lignie.

Radio

Radio work is a simple but useful means of checking the overall meteor activity; rain, clouds, daylight, city lights, ... all these problems to visual and photographic work are ruled out. No radar is needed. For instance commercial broadcasting stations beneath the horizon produce sufficient radio waves to be reflected by meteor trails, if geometric circumstances are favorable. Radio meteor work is rather unpopular and poorly known; the IMO intends to change this situation and has therefore created a radio observing program. The aims of this program are:

• to cover the overall meteor activity on a more continuous basis (day and night), down to the fainter, poorly studied, magnitude classes (+10);
• to study the relationship between visual meteor appearances, their brightness and the duration of the received radio echo signal.

For further information and questions about radio work within the IMO, the Radio Commission will gladly assist you.

Radio Commission Director: Jean-Louis Rault, Société Astronomique de France, 16, Rue de la Vallée, 91360 Epinay sur Orge, France.

Telescopic

Telescopic work: the IMO wishes to encourage this observing technique among the owners of binoculars. Therefore a Telescopic Commission has been set up within IMO, led by experienced people. A number of articles in our meteor library are available and may serve to further develop this observing technique.

The director of the IMO's Telescopic Commission will be happy to answer further questions.

Telescopic Commission Director: Malcolm Currie, 25 Collett Way, Grove, Wantage, Oxon OX12 0NT, United Kingdom.