Items tagged gps in Jan, 2010
Filters: Year: 2010 × Month: Jan × gps × Sorted by date
OSM the default map in Haiti. A search and rescue team member in Haiti sends word that digital maps constructed by the OpenStreetMap community are spreading by word of mouth and being loaded on to GPS units on the ground. # 25th January 2010, 9:26 pm
GPS and Relativity (via) GPS satellite clock ticks need an accuracy of 20-30 nanoseconds. The satellites move fast enough that their clocks fall behind by 7 microseconds a day due to time dilation, but orbit high enough that the curvature of spacetime due to the Earth’s mass puts them forward by another 45 microseconds. GPS receivers have to perform relativistic calculations to determine their location! # 11th January 2010, 9:17 am