Meteor Science:   Observing Methods Summary

Follow the indicated links here and on the Overview page for more details. 

This portion of our site exists on behalf of Radio Observing. Apart from brief reference on this page to other methods, to establish a foundation for comparison, we'll focus our discussion accordingly.

Review of Methods:

• Visual: Organized observers lie on lawn chairs, fighting off mosquitoes or trying to avoid hypothermia while they count the numbers of meteors they see arriving from a particular direction and/or within an area of the sky allocated to them. This may sound chancy but it works and has the advantage no other method can claim that the observer is able to enjoy the beauty of the display first-hand. This can be a very reliable way for determining influx rates and pinpointing radiants. Drawbacks include inattention arising from discomfort or tedium, inability to detect objects not leaving visible tracks, light pollution and difficulty in obtaining/training good observers. Visual methods are incapable of determining much more about a meteor event than its direction and approximate intensity.
  
  
• RADAR: HF and VHF  RADARs are sensitive to ionization effects (more on this in the Radio Observing link) enabling automated counting, accurate velocity determination, polarization analysis, etc.  Amateur investigators are unlikely to have the resources for putting together a serious system and licensing for operation is problematic. The analytical capabilities are impressive, however.
  
  
• Optical/Video: Automated still and video camera arrays, benefiting from computer control and analysis of images are replacing both amateur and professional visual observing programs. Remarkable work is being done. For anyone at all interested in this approach we recommend: 

        www.imo.net/video/index.html

• Radio (Passive RADAR)- the basis of this site: Relies on commercial or beacon transmissions at HF and VHF to illuminate meteor ionization tracks - the so-called forward scatter method. By this means many of the interesting analytical methods enabled by RADAR become available at a low cost and with more readily obtained or easily designed equipment. Principle drawbacks are ambiguities resulting from multiple transmitting sources,  inability to control positioning of the illuminating source and occasional interference arising from ionospheric instability.

RADAR and Radio observing methods enjoy the obvious advantage that they are unaffected by "seeing" conditions. A bright moon, urban light pollution, bad weather or time of day (let's say high-noon to take a worst case scenario) are the bane of visual/optical methods. With the possible exception of local thunderstorms, radio is impervious to most phenomena adversely affecting optical methods.

Despite some definite drawbacks radio observing is an essential complement to other methods, sustaining acquisition of useful data when other ways are obstructed.