5 ms·
They note 'In this paper, all GPS measurements are assumed to be processed differentially', I assume you couldn't get centimeter accuracy without DGPS?
by deutronium 11y ago
They note 'In this paper, all GPS measurements are assumed to be processed differentially',
I assume you couldn't get centimeter accuracy without DGPS?
- deleted 11y ago[deleted]
- eps 11y agoYou can get a millimeter accuracy without DGPS, but you need several hours worth of signal for a single spot. This is not a new tech (or a math rather), it's been around since the early 90s if not longer, and it has interesting practical applications like measuring dam movements.
- mojoB 11y agoDam monitoring systems use DGPS, one receiver on the wall, the other nearby. Without a local reference station, atmospheric and ionospheric disturbances would totally overwhelm the effect they are trying to measure. This [1] covers it quite well. [1] http://pasadena.wr.usgs.gov/office/hudnut/SRL/ http://pasadena.wr.usgs.gov/office/hudnut/SRL/
- eps 11y agoSure thing, that's the simple way :) It was in mid 90s, but I can guarantee you that I sat next to a math PhD guy who worked exactly on what I described, including the dam deployment. Single receiver, 3mm precison from 3-4 hours of data, no DGPS. This wasn't in the US though.
- xemoka 11y agoAnd before selective availability[0] was turned off? So did he have military GPS equipment and not consumer grade? [0] http://www.gps.gov/systems/gps/modernization/sa/ http://www.gps.gov/systems/gps/modernization/sa/
- jevinskie 11y agoVery interesting data. It was cool to notice some graphs had much higher variability and then notice that they were all sites that are far from the equator. Then the article helpfully explained precisely why they had more variance!