SEASAT Earth Images Options

[PhilHorzempa]

SEASAT was a pioneering mission in using SAR to produce images of
a planetary surface. It was the true precursor mission that made Magellan,
the SRTM (STS-99), and Cassini possible.

It was launched in 1978 and its mission was relativley short.
Even though its main mission was monitoring sea surface conditions, its SAR
produced a good number of high-quality images of the continents.

Does anyone in the UMSF community have good Earth images from SEASAT
that they could share? Those images seem to be scarce on the Internet.
Also, images of the SEASAT spacecraft itself would be neat to see.


Another Phil

[djellison]

http://www.google.co.uk/search?q=seasat&am...earch&meta= ?

Doug

[PhilHorzempa]

Thanks for the Google search reference - However, what I am looking
for would be any recent work that may have been performed with Seasat's
Radar imaging data. The Seasat Atlas that is linked in the Google search
is 25 years old. The images are adequate - however, I think that they
could be cleaned up and stitched to form mosaics. In addition, if you look at
the SAR coverage charts in the back of the Atlas, it appears that long swaths
of terrain were imaged. It would be nice to see those swaths for reasons of
science, beauty and history.

Also, actual photos of Seasat hardware during ATLO seem to be scarce.
In addition, it is my guess that the Agena upper stage "host" was based on
earlier NRO imaging satellites. Does anyone know if that is the true heritage of
Seasat?


Another Phil

[tedstryk]

Well, Phil, dig in...we'd love to see what you come up with!

[Guest_Analyst_*]

Also, actual photos of Seasat hardware during ATLO seem to be scarce.
In addition, it is my guess that the Agena upper stage "host" was based on
earlier NRO imaging satellites. Does anyone know if that is the true heritage of
Seasat?

Agena was used extensively for NRO payloads, but also for many NASA mission like Mariner, Ranger, Lunar Orbiter to name a few. Many NRO payloads were designed to use Agena as a host, providing attitude control etc. Seasat did the same, contrary to the NASA probes above who used Agena as an upper stage only. So Agena was not "based on" NRO satellites. This should be no reason for a lack of photos.

Did Seasat has its roots in NRO programs? I really do not no. I doubt. It has been a NASA program.

Analyst

[dvandorn]

The Agena was originally developed as an upper stage that would serve as the foundation for the early Keyhole (or KH) spy satellites, but it was used from the outset as a generic upper stage for the Atlas rocket. Not only was it the upper stage of choice for many satellites and planetary probes throughout the early and mid 1960s, it also served as the rendezvous target for Gemini spacecraft.

IIRC, the Agena was the first three-axis-stabilized upper stage developed by the U.S. That made it quite in demand for planetary probes (which, at the time, you didn't want to put into a spin prior to escape trajectory injection), as well as for any satellite that you wanted three-axis-stabilized but didn't want to spend the time and money to develop an RCS for... This was a requirement for the early KH series, but it was a happy circumstance for a whole generation of spacecraft designers.

As for SEASAT in particular, I don't believe it was primarily an NRO type of mission. Yes, a lot of the SAR flown by the U.S. has been NRO-related (primarily to get good ground elevation maps for cruise missile navigation), but SEASAT itself was, IIRC, for scientific research. It's easy to confuse this, since the USSR flew a lot of oceanic radar surveillance spacecraft whose jobs were to track U.S. naval movements (including, it was hoped, shallow submarine assets). The Russian SAR required so much power that they flew with actual fission-pile nuclear reactors; it was one of these that crashed onto Canada, spreading nuclear material over the countryside. American SAR missions have used solar energy (or, in the case of the Shuttle-borne SAR, fuel cell-generated power).

-the other Doug

[Paolo]

If you have access to www.sciencemag.org you can find the preliminary results of Seasat in vol. 204, from page 1405 on.
And there is a very good article on SAR, which includes lot of Seasat imagery in vol.209 from page 1073.
BTW, there are quite some infomrations on Seasat and a radar picture in the new book "into the Black" http://www.thespacereview.com/article/809/1