Prove it: rover in RTK solution are using GPS L5?

[Zove]

Hello dear professionals,

My studies about compare state VRS ref. network and own base transmitting corrections throe NTRIP (sorry we don't using UHF or any other radios) rise a question:
- What in reality are transmitting from Base receiver / network, what rover receiving and what signals rover are using in RTK solution?

Reading GREIS page 67-68 Satellite Navigation Status Value can be "7x", for example "79 - C/A L1, L2C, and L5 slots are used in RTK processing".

Q1: Who of you can show me confirmation that your rover get Status with number "7x"?
Q2: How you configure your base and rover, NTRIP caster to get one of Status wit "7x", it mean with GPS L5?

By the way I can use only old Triumph-1 which alone are tracking GPS L5 or event newest L1C.

Than you in advance and good luck to You!.

 

[Javad]

Please click the RTK status button and see the details of each RTK engine. It will show you which signals are used for each RTK engine and how many of each signal. Did you update to the latest release version?

 

[Nistorescu Sorin]

From (TRIUMPH-1 G3T) Knowledge Base: starting from 3.7.7 firmware, RTK doesn't use C/A L1, L2C, and L5 (SS=79), in triple-frequency combination ;
CA/L1 and L5 (SS=72) could be used in double-frequency combination, only when P2/L2C are disabled.

In my understanding, the acquisition of the multiple/modern signals (L5 included) is most of the time more complex than the older L1/L2, because the receiver's Digital Signal Processing module (DSP) must "deliver" enough sampling "speed" with a smaller "step" (that means faster processors), in order to preserve all the signal(s) information and to correctly aproximate/represent in a digital version all the satellites analog data received from antenna, for a complete multi-signal/constellation RTK solution.



I think using L1/L2/L5 signals in RTK solution could be difficult to prove for the old Triumph-1 receiver..

 

[Zove]

@Nistorescu Sorin thank You for explanation, Your answer 100% shot what I wanted to find out. I think I read everything, where I can read T1 KB?

With SNIP I check state ref. stations NTRIP streams and only one mountingpoint has GPS L5 (CMRx is closed for me), then on T1 rover ca,off & p1,off and T1 show me Status=77.

T1 is old and maybe I don't expect as RTK rover L1+L2+L5 solution, at his age, I expect, that T1 can be normal receiver for NTRIP ref. base station.

Today I try to find answer: T1 > NetHub NTRIP work as base and T1 track and I hope transmitting all these signals GPS (C/A L1, P L1, P L2, L2C, L5, L1C ) + GLN (C/A L1, P L1, P L2, C/A L2 ) + GAL (GAL E1, Е5А), how Javad and other vendors rovers are working, will it be L1+L2+L5 or L1+L2 solution on rover side?

 

[Nistorescu Sorin]

@Zove
Knowledge Base (must sign-in): https://www.javad.com/dynamic/KnowledgeBase/Home
Look for "RTK in firmware, V 3.7.7" and also "C/A code for L1C/L2C/L5 positioning" could help.

Note that on a daily basis, there are fewer satellites with L2C/L5 than those with CA/L1, P/L1, P/L2; watch your engines behaviour with L2C and L5 (SS=77) configuration; take a look at your RTN capabilities and in particular at the receiver installed at your closest mountpoint;

I think that someone from Javad should post any useful information for a GPS (CA/L1, P/L1, P/L2, L2C, L5, L1C) + GLN (C/A L1, P L1, P L2, C/A L2 ) + GAL E1/Е5А base-rover behaviour or a maximum signal configuration supported for the old TRIUMPH-1 receiver (with consideration to many T1 users worldwide), if possible.

Last but not least, the rover will use as much signals as the base transmits and I will be happy if "officials" will prove the above capabilities for the old TRIUMPH-1 receiver.

 

[Zove]

@Nistorescu Sorin thanks, I will read KB.

Sometime our T1 show 12 GPS (10 used) and 6 SV with L5. Frankly, I have always considered that L5 is used as a priority in RTK solution, but I was wrong.

About RTN, I know that all ref. stations antennas and receivers can tracking everything, but on server side is old SW with many NTRIP VRS mountingpoints and only one carries L5.