On 08/16/2013 05:44 AM, David Taylor wrote: > On 15/08/2013 21:33, Magnus Danielson wrote: > [] >> They completely avoid it by not numbering it that way. They have their >> own numbering scheme that fit's the system, and the conversion over to >> UTC is an added feature. It's all in ICD-GPS-200 for the current set of >> details, and in the ION red book series for the early stages. >> >> GPS and GPS problems is best understood if you realize that everything >> is counted in the GPS clock machinery with it's own set of gears. >> Conversion isn't that hard and it is done every second in the GPS >> receiver. >> >> Cheers, >> Magnus > > Thanks, Magnus. I've not heard of ICD-GPS-2000 or ION red book > before. Perhaps one day I will look them up. If you go here: http://www.gps.gov/technical/icwg/
you will find IS-GPS-200G (which is the new name since 2006, I have failed to adapt) on this link here: http://www.gps.gov/technical/icwg/IS-GPS-200G.pdf Using ICD-GPS-200D gives a fair idea of what the older GPS receivers was designed to meet. In these documents, the "gears" of GPS is explained such that you should be able to implement a correctly working receiver (in principle). There are a handful of technical details outside of this spec you need to figure out too, but there are good books for that. > GPS continues to impress me - I counted and on holiday recently we > took (at least) 7 GPS receivers - his and hers smart-phones, 2 iPads, > Garmin GPS 60 CSx, Ventus 750, and one built into my Sony HX200V > camera! The Garmin spent much of its time with a puck antenna stuck > on the cabin porthole plotting our course. They have gone small now, but you still have L1 C/A only receivers. Many of them probably does not use carrier phase in any way. Cheers, Magnus _______________________________________________ questions mailing list questions@lists.ntp.org http://lists.ntp.org/listinfo/questions
