Wednesday, September 30. 2009

GPS in the Snow

Recall that one of the errors in GPS is called "mulitipath error" - that's when the signal from the GPS satellite bounces off something before it gets to the receiver, making its path artificially "longer." Its noise for most applications, but in fact is valuable in ... wait for it... measuring snow depth. Researchers at the University of Colorado, Boulder, looking to learn about the impact of soil moisture on the echoes found their experiment in the middle of a snow storm. That lead to a startling realization: "The snow slowed the reflected GPS signals, and the delay corresponded to the snow's depth..." That in turn led to a method to accurately measure snow fall in real time. The team's paper, in Geophysical Research Letters appeared this month.

- ScienceNow

Posted by Adena Schutzberg in GPS, Remote Sensing at 07:24 | Comments (2) | Trackbacks (0) |

Friday, September 18. 2009

Mass Supreme Judicial Court: Installing GPS with Warrant OK

The highest court in the Commonwealth of Massachusetts upheld the right of police to install GPS tracking device to track suspects so long as a judge grants a warrant. The court ruled, unanimously, that such action "does not violate the ban on unreasonable search and seizure in the state’s Declaration of Rights."

But, there are some stipulations: The officers, must of course convince a judge a warrant is appropriate and the "devices can be installed for up to 15 days before police must show why the devices need to remain in place."

- The Boston Globe

Posted by Adena Schutzberg in Tracking, GPS at 07:37 | Comments (0) | Trackbacks (0) |

Tuesday, September 15. 2009

How the GAO Report on GPS Helps/Hurts the Program

The GAO report [APB coverage] “helps because it puts a lot of emphasis on the budget for future satellites and things like that,” said Col. Robert Hessin, acting director of the National Coordination Office for Space-based Positioning, Navigation and Timing, a government agency that tracks GPS legislation and the health of the constellation.

Where it hurts, he said, is on the international front, where China, Russia and Europe are developing their own satellite navigation systems. “We’re competing with the rest of the world on precision navigation,” Hessin said.

Posted by Adena Schutzberg in GPS at 06:00 | Comments (0) | Trackbacks (0) |

Thursday, September 10. 2009

GPS Satellites to Get Better Clocks

Massachusetts based PerkinElmer received a $15 million contract from ITT to update the atomic clock technology it provides for the Global Positioning System satellites.

- Mass High Tech

Posted by Adena Schutzberg in GPS at 09:00 | Comment (1) | Trackbacks (0) |

Tuesday, September 8. 2009

Podcast: What Your Relationship with your GPS Says About You

In this special "vacation" edition of the podcast, our editors turn their attention to a piece of geospatial technology they both use: the Garmin Forerunner "GPS watch." There's quite a bit of disagreement about what's expected of the device and what's wanted in future versions.

Posted by Adena Schutzberg in GPS, Weather, Directions on the News Podcast at 01:00 | Comments (0) | Trackbacks (0) |