I am very interested to have this answered. Does anyone know? GPS Refresh Rates By matthev - Wed Mar 22, pm.
The data is real, not repeated or interpolated. They're expensive. Javad also makes faster ones 20Hz , but as with any high-update-rate source, you end up with lots of data. Depending on what you're doing, it's hard to justify such high data rates. If you're doing a realtime display, you can't visually process 10Hz data.
If you're logging data say from a tracker all but the fastest moving objects could be tracked fine with a lower update rate and you end up with much smaller data files. The only slow objects I can see needing quick updates are UAV's using the data for realtime control. I imagine that if you tried quickly query one of the cheaper receivers that is specified for a 1Hz output rate , you'd end up with the same position repeatedly between fixes.
By coyotebush - Sat May 20, am. Despite the price, it is one of my favorites. Usually, if you want the higher update rates you also want the extra precision from double differencing. It doesn't make sense to get more frequent updates unless they are very accurate or unless you are going very fast.
Other choices include the Garmin gps18 with 5 hz update, and some of the Superstar II receivers. By TomHale - Wed Jan 23, pm. I'm after something less than an ounce in size. I also would like it to have a fast refresh rate something in the area of five times a second or faster.
I realize most GPS units have screens etc that make it difficult to be truly ultralight. I was wondering if there was just the GPS unit without any additional components or perhaps a passive gps unit that gets powered like a passive RFID chip and would relay its quickly refreshed positional data to a main terminal.
But there is nothing to stop a GPS module from calculating fixes at a faster rate. And as you hint or suggest, if you have an IMU, you can also potentially use dead reckoning to estimate position in between fixes regardless of fix rate. It could re-compute position as often as it likes, but for the output to be sensible, it is smoothed over a long time, perhaps a second or more.
For example the maximum acceleration might be limited to 2 g, which could make its step response to a sudden stop slower than 1 second anyway. Add a comment. Active Oldest Votes. I assumed that the signal from the satellites was at 1Hz and that was the restriction.
What is the rate coming from the various satellites? I would guess that the military GPS offer much higher update rates and also much better accuracy. But it does not sound like you need to control fast moving objects like rockets in your application. The satellites simply transmit orbital ephemeris data and the time of day at bits per second and a CDMA chip rate of 1.
The GPS receiver maintains a lock on the CDMA spreading code and uses that to determine the time of arrival differences between the satellites. Getting a lock in the first place takes a while, but after that the position can be updated at a rather high frequency. I'm not sure what the upper limit on that is. So the GPS receiver has to lock on to the chip edges very precisely so it can get a fix accurate to a couple of meters.
Rendeverance Rendeverance 3 3 silver badges 13 13 bronze badges. Sign up or log in Sign up using Google. Each satellite circles the Earth twice a day. The satellites in the GPS constellation are arranged into six equally-spaced orbital planes surrounding the Earth. Each plane contains four "slots" occupied by baseline satellites.
This slot arrangement ensures users can view at least four satellites from virtually any point on the planet. The Space Force normally flies more than 24 GPS satellites to maintain coverage whenever the baseline satellites are serviced or decommissioned. The extra satellites may increase GPS performance but are not considered part of the core constellation. Three of the 24 slots were expanded, and six satellites were repositioned, so that three of the extra satellites became part of the constellation baseline.
As a result, GPS now effectively operates as a slot constellation with improved coverage in most parts of the world.
Learn more at spaceforce.
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