[Prev][Next][Index][Thread]
Re: (meteorobs) Radio Observation of Meteors
At 10:42 AM 8/21/99 , Ron (in Gander) wrote:
> To expand the idea, we use the same principles that are used in
>aircraft radio altimeters, either wideband swept FM modulation or pulse
>modulation, we may be able to actually measure the closest range of the
>meteor.
I'm not certain of what you're getting at here. Would the beacon send a
time code (one of the IRIG codes, say, the one that uses a 10 kHz carrier).
The receiving station could then calculate the dealy of the time code and
determine the total path length. Wind velocity could also be calculated
from the doppler shift. If the receiving site did interferometry, or if two
receiving sites were used for triangulation, the meteor altitude could be
determined, as well as the lat/lon of the burn.
I think you'd lose a lot of data if you only ran 100 W, though. At 25 kW at
50 MHz we had plenty of signal to work with for most meteors, but about
10-20% were too far down in the noise to be useful for analysis (we were
looking for atmospheric density and wind data, not doing meteor astronomy
at the time).
> The system could be as simple as a single transmitter and receiver with
>computer logging to sort out reflections from non-meteoric reflections
>(overflying aircraft, etc.). Or I could envision a 5 station array, a
>single beacon in the centre of an X and receivers N, E, S, and W of the
>beacon. Meteors passing overhead the array that were detected by more
>than one receiver, and if the time of the reflection was logged with
>some precision, along with altitude, we may be able to roughly determine
>velocity - its speed and direction.
Put some optical instruments in key positions and you could develop quite a
data set!
73,
John
KO6X
====================
Visit: http://www.jelder.com
====================
One does not become enlightened by imagining figures of light,
but by making the darkness conscious.
-- C. G. Jung
To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html
Follow-Ups:
References: