Satellite imaging in Space News
Allen Thomson (thomsona@netcom.com)
Tue, 13 Aug 1996 11:44:55 -0700
This item appears in the current Space News and may be of
interest to the Seesat-l list, though most of the material has
already appeared in other places. Partly in order that the
article enter the archive, I'm posting the entire text and
hoping that the restricted dissemination of the mailing list
will keep me out of trouble with the copyright police. Please
don't repost this message on a public newsgroup without trimming
it heavily. (I'm going to post excerpts on some sci. and alt.
groups later today.)
Seesat-l'er Ron Dantowitz might like to comment on the article.
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New Software Enables Amateurs to Track Satellites
By Leonard David
Space News Correspondent
Space News, August 12-18 1996, p. 8
WASHINGTON - Off-the-shelf telescopes, sensors and software are
now so powerful that amateur skywatchers are able to track and
photograph orbiting spacecraft with a degree of detail
previously available only to the military. Satellite sleuthing
equipment and techniques have reached a new level of maturity,
spurred by work conducted at the Boston Museum of Science's
Gilliland Observatory in Massachusetts.
At the museum's observatory, nodest-sized ground telescopes
have been outfitted to track satellites precisely as they move
across the horizon. Images are then taken using a video camera
that incorporates a charged coupling [sic] device - a light
detector several hundred times more sensitive to light than
photographic film. The videotape recording of a spacecraft can
later be analyzed, frame by frame. Typically, some of those
frames are nearly free of atmospheric distortion and show a
surprising amount of detail, said Ron Dantowitz, an employee of
Boston's Charles Hayden Planetarium. Dantowitz has spearheaded
the satellite tracking effort.
"It's amazing what amateurs can do with advents in technology
and computers," Dantowitz told Space News in a July 26 phone
interview. "It's a great project to work on. It has taken
about a year from start to where we are now. We've developed a
pretty smart little system here." A favorite target is Russia's
Mir space station, which is much larger than most satellites.
Imagery taken through the computerized telescope tracking
hardware can discern Mir itself, replete with solar panels and
docked Progress and Soyuz space-craft. During linkups between
Mir and space shuttle Atlantis, the complex of vehicles is
easily observable, Dantowitz said. Other targets have included
the National Reconnaissance Office-sponsored Tether Physics and
Survivability experiment, deployed June 20. Excellent video of
the tethered components was obtained, Dantowitz said, at the
request of the Naval Research Laboratory, which built the
experiment.
Imagery also has been collected of burned-out rocket stages,
such as a Russian Zenit booster tumbling through space, and a
number of U.S. scientific, military and intelligence-gathering
spacecraft.
"We actually have been able to observe the Lacrosse and
other spy satellites at extremely high resolution. But we're
not interested in publishing any of those pictures," Dantowitz
said. Lacrosse is a radar imaging satellite operated by the
National Reconnaissance Office.
"Quite honestly, if they [the U.S. military] want to keep
them private, I'm going to give them that right. Just because
we can look at them doesn't mean we should publish [the
pictures]," Dantowitz said. So far, the ability of amateurs to
peek in on classified satellites, does not have the military
concerned.
"The U.S. Space Command is not concerned about the amateur
capabilities for any of the satellites that, we control," said
Franki Webster, a spokeswoman for the U.S. Space Command at
Peterson Air Force Base, Colorado Springs, Colo. Dantowitz said
that the satellite tracking software for telescopes is now being
sold to other amateur astronomers and observatories.
Marek Kozubal, an intern student at the Boston-based Hayden
Planetarium from neighboring Brandeis University, worked on the
software and other special features that run the satellite
observing telescope system. "My interests in computer sciences
and astronomy came together in this project," he said.
"You can pretty much track any satellite from horizon to
horizon through the whole pass," Kozubal said. Orbital elements
for satellites - such as inclination, attitude, passage time
over a certain area, etc. - can be gathered from online Internet
services.
These satellite elements are then converted for input into
the computer software that runs the satellite tracking telescope
hardware, he said.
"At any one time, there's probably about 800 different
satellites above us, and probably 80 of them are in low Earth
orbit. By hitting a key, typing in the name of the satellite,
the telescope tracking can quickly switch from satellite to
satellite ... those that are visible from our location at that
very time," Kozubal said.