We have GPS that's the USA system. L1 L2
What about more signals from them? ie L5?
Then, there is GLONASS.
There is the European system Galileo
The Chinese system. Beidou, or Compass,
And, when are more supposed to be turned on?
Thanks!
Nate
PS there is apparently also a Japanese system too:
Quasi-Zenith Satellite System (QZSS)
Why Would You Want To Know?
Unless you have plenty of money to buy the most expensive new GPS, you already have what you need.
First though I'll answer your question.
Currently 31 GPS satellites are active. Of those the following GPS IIR-M are L2C capable, listed by SVN (Space Vehicle Number)/PRN (broadcast number = PseudoRandom Noise)
48/7
50/5
52/29
53/17
55/15
57/29
58/12
49/30 was modified to broadcast a test L5 signal but antenna cross connections make it uselss for L1/L2, so it is up ther ebure unuasable.
The following GPS IIF are L2c and L5 capable and up there.
62/27
63/1
65/24
66/27 just turned on last week.
The Air Force just finished a week of L2C/L5 testing, but it is doubtful that they will be available and useful for several years.
GLONASS has been keeping a full constellation and should continue to do so.
The other systems are years from being useful in the US.
If you want to get the most improvement you currently can get receivers that are GPS/GLONASS capable and can do ranging calculations from SBAS satellites (WAAS, EGNOS etc.) That would be he Ashtech BLADE technology, soon available from others.
In new things India is preparing a highly elliptical geosynchronous SBAS system to work with GLONASS. That is a supplementary system like WASS, EGNOS and the Japanese system.
Paul in PA
Why Would You Want To Know?
OK, Paul, I have an opportunity to buy a 4 yr old set of Triumph-1 GPS receivers. Or I can buy a new set, that can track the newer sats. I want to look at the cost diff.
Nate
If You Buy A New Set...
...it well be well used by the time those satellites are useful.
So what is this newer used set going to give you that you do not already have? I understood you to hve Topcon L1/L2 GLONASS.
Paul in PA
Why Would You Want To Know?
We operate with only Trimble equipment, so I can only offer an opinion based on their gear. That being said, the new Trimble R10's are a moderate improvement over the last generation of GPS (R8 model 3). At the firm I work at we have Trimble R8 model 1, R8 model 3's and now a couple of new R10's. We operate both base and rover and network RTK. I had the opportunity in the last couple of weeks to really put the R10's through the paces; working in the woods of the Pacific Northwest, dense canopoy, etc. The step up from R8 model 1 to R8-3 is significant...really "light years" better. The jump from R8-3 to R10 is less so, but the R10 are definitely more robust (i.e. keep a fix longer, cook down to better accuracy, etc.) There were a couple of shots that the R10 unit took that I was surprised that it resolved and stored. Here's one almost directly underneath a 100" maple tree with significant canopy.
Afterwards I pulled out the total station, set control in a nearby field and tied this location with the robot to double check the GPS shot and it was less the a tenth in horizontal and vertical, which was well within our tolerances for this project.
Why Would You Want To Know?
It does seem that there have been improvements in the last few yrs, in all GPS systems.
IF you had moved over 3'-10' and shot another RTK shot, and compass and dist between them, you could have a check on bad init. I do this, for hard to reach places, in the boonies.
N
