Explorer1
Member

Registered: Sep 1999
Location: Deep Space.
Posts: 76 |
Encouraging news. Beta team members were also allowed to preorder on December 18 and 19. But since I was the 46th person to order a visor when they were introduced last year but still waited almost 4 months for it to actually arrive (and then returned as defective), I'll keep a 'wait-and-see' attitude until my Geode arrives.
BTW: For those interested in GPS's, JPL is experimenting with a GPS for satellites that's accurate to 3 cm, yes centimeters. The news release is below. Maybe someday this technology could make its way to consumers.
http://www.jpl.nasa.gov/releases/2000/blackjackgps.html
MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Contact: Rosemary Sullivant (818) 354-0474
FOR IMMEDIATE RELEASE December 15, 2000
"WHERE AM I?" NASA'S BLACKJACK RECEIVER KNOWS THAT AND MORE
While an ordinary global positioning system (GPS) receiver uses information carried by radio signals from a constellation of GPS satellites to
calculate its position, NASA's BlackJack GPS receiver looks at the radio waves themselves. By making precise measurements of how the signals
are distorted or delayed along their way, the BlackJack provides a new way to study Earth's gravity field and atmosphere.
The first of these experimental receivers is flying on a German scientific satellite, Challenging Minisatellite Payload (CHAMP), launched in
July. The second is onboard an Argentine satellite called SAC-C, launched on November 21. Both instruments were designed and built at
NASA's Jet Propulsion Laboratory in Pasadena, Calif.
"Like any other GPS receiver, the BlackJack can calculate where it is in space and time, but comparing the BlackJack to an ordinary GPS
receiver is like comparing a home camcorder to a professional studio camera," said JPL engineer Thomas Yunck, manager of the GPS
Observatories Office. While a typical GPS receiver can determine its position to about 20 meters (22 yards), the BlackJack can pinpoint the
position of its host satellite continuously with an accuracy of 2 to 3 centimeters (.8 to 1.1 inch). This flight data can be used to improve computer
models of the Earth's gravitational field, which in turn can help reveal different Earth properties, including the structure and evolution of the deep
interior, the movement of surface ice and atmospheric mass, and ocean circulation.
In a more dramatic departure from conventional GPS use, BlackJack receivers track the radio signals slicing through the earth's atmosphere
as the GPS satellites appear to rise and set. This information will help scientists construct detailed images of the ionosphere and will provide
precise profiles of atmospheric density, pressure, temperature, and moisture for climate studies and weather prediction. The BlackJacks are also
equipped with small down-looking antennas to attempt to receive GPS signals that reflect off the oceans. This highly experimental technique could
one day be used to map the subtle variations of the ocean topography, derive ocean circulation patterns, sense the roughness or state of the ocean
surface and estimate surface winds.
The SAC-C and CHAMP experiments are early attempts to assess the engineering feasibility of such measurements. Both experiments are
designed to last about 3 years.
JPL is a division of the California Institute of Technology in Pasadena.
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12/13/00 RS
#2000-129
[Edited by Explorer1 on 12-21-2000 at 01:17 AM]
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