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.