[Prev][Next][Index][Thread]

Re: (meteorobs) Re: [Fwd: Question to list]




>> Someone please correct me if I am wrong, but as a radio telescope,
Aricebo
>> should be passive and transmit no signal at all. It is more akin to a
telemetry
>> receiver for non-manmade signals rather than a radar which does transmit
>> extremely high peak power signals of very limited duty cycle.
>>
>> Phil Rogers
>> progers@mindspring.com
>> ********
>
> Actually, Aricebo can transmit radio waves.  For SETI purposes, it
>only listens, but it is capable of transmitting a signal.  It radar imaged
>Venus in the 1970's and it also transmitted a signal to a globular cluster
>in 1973, I think.


The 305m antenna at Arecibo frequently in use as a planetary radar, and is
used very successfully as a meteor radar as well.  See:

Mathews, J.D., Hunter, K.P., Meisel, D.D., Getman, V.S. and Zhou, Q., Very
High Resolution Studies of Micrometeors Using the Arecibo 430MHz Radar,
Icarus, 126, 157, 1997.

Zhou, Q., Unusual Characteristics of Meteor Echoes Observed by the Arecibo
430 MHz Radar, Proceedings of the 7th International Workshop on Technical
and Scientific Aspects of MST Radar, pp. 314-317,SCOSTEP Secretariat,
Boulder, CO, 1996.

Zhou, Q. and Kelley, M.C., Meteor Observation by the Arecibo 430 MHz ISR
Incoherent Scatter Radar.II. Results from Time-Resolved Observations, J.
Atmos. Terr. Phys., 59, 739, 1997.

Kelley, M.C., Alcala, C. and Cho, J.Y.N., Detection of a Meteor Contrail and
Meteoric Dust in the Earth's Upper Mesosphere, J.Atmos. & Solar-Terr. Phys.,
60, 359,1998.

Zhou, Q.H., Perillat, P., Cho, J.Y.N. and Mathews, J.D., Simultaneous Meteor
Echo Observations by Large-Aperture VHF and UHF Radars, Radio Sci., 33,
1641, 1998.

At 430 Mhz, the radar is capable of something like 2.5 Gw.  The power supply
to the final amplifier runs 63kv at 33 amps.  That'll make your hair stand
on end.  With all that juice, you can understand how they can detect things
like the SOHO satellite at 1.5 million km, and tell you how fast it's
spinning.

Jim Bedient







To UNSUBSCRIBE from the 'meteorobs' email list, use the Web form at:
http://www.tiacdot net/users/lewkaren/meteorobs/subscribe.html