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Re: (meteorobs) Radar equipment to monitor meteors
At 10:57 AM 12/14/97 EST, you wrote:
>Steve;
>Thanks, very interesting, then it can be done.
>I would like to get a schematic to build something
>like this.
Ray, the hardware of a rudimentary meteor radar would not terribly
complicated. Basically, all you really need is a transmitter with very fast
on/off keying (CW keying), a decent receiver with ability to turn off the
AGC, and a very fast PIN diode transmit-receive switch which is tied in with
the transmitter keying. Then there's the question of how to record the data
from the receiver.
I won't go into further tech details here (wrong place, and wrong time since
everybody is observing a major shower in these days); but you can find much
information on the web page I mentioned earlier at
http://ham.te.hik.se/homepage/sm5bsz/
That address will lead you to other pages by the same author which will
provide much more information on the hardware. The project *IS*
technically-involved and *DOES* require an extensive background, knowledge
and understanding of both radio transmitters and receivers, plus a fair
accumulation of test equipment with which to measure everything.
Modification of existing equipment, either from the amateur radio market or
government surplus, would allow the cost to be kept to less than $USD1K (I
think; at least, the stuff I have around here with which I would try to
start sure isn't worth much more than that!); but again, there is the
question of what kind of data you would want to have, and in what format.
These considerations would define the design some of the receiver system
modifications. In addition, the data recording system should also, but
doesn't really have to, perform some minimal control of the transmitter.
What I'm trying to point out without getting technical here is that prior
knowledge of how such a system works, what hardware is required, and an
understanding of how the hardware is tied together, is what allows one to
keep the cost way down compared to buying a commercial ready-to-operate
system. Without that in-depth knowledge and understanding, things get a lot
more complicated real quickly.
It's something like building a telescope camera with automatic shuttle and
pointing system. Drawings of the system and its components would certainly
give me, who has never even seen such an animal, a warm, fuzzy feeling that
it *is* buildable. But those drawings also do not tell the whole story; how
to grind the telescope mirrors and lenses, for example; nor how calibrate
the camera or telescope; nor how to set up a data recording system.
Obviously, I can cut costs way down by buying what I can and designing ways
to tie it all together into a system even GeoZay would be proud of :') ! But
without a reasonably-in-depth theoretical and technical understanding of the
system and its targets (the visual meteors and their behavior), I would not
likely wind up with much more than a pile of ruined junk; I would have been
better off, both time and money-wise, to commission George to design and
build one for me from scratch!
So while one could come up with a lot of schematics and other drawings of a
rudimentary meteor radar, they probably wouldn't do too much good to
somebody else initially, without them delving much more deeply into the
theoretical and technical details of what constitutes such a system (that
web page I mentioned above provides much of that insight). This is because
in order to keep the costs down so far, you would have to know what to look
for, where to find it cheap, how to make do with what equipment you can
find, and know how the equipment works so you can design and perform the
appropriate modifications.
Ray, I'll respond to further questions privately since this is starting to
get pretty far off-topic. To the other visual observers, thanks for your
patience! Also, thanks to you all for listing your observations and
discussions here; even though my own main interests in meteors lie in the
radio reflection aspects, the information I read here from you folks goes a
long way to helping me better understand what I observe with my equipment.
It's often difficult to decide whether I really want to sit in front of a
radio listening to hiss for hours on end, or to go outside in the cold and
try to see what I can in this light-polluted city. The descriptions of
fireballs from you all often make me wonder whether I was bouncing my radio
waves off of those same meteors while you were watching them burn.
If I don't have occasion to post anything else before the holidays, the best
of the season to you all!
Clear skies,
SteveH
Shrewsbury MA