Testing Triumph-LS GPS+GLO+GAL+BDU in Canopy

Shawn Billings

Shawn Billings
5PLS
I received my Triumph-3 a couple of days ago and finally had the chance to set up a test. As a word of encouragement, the Triumph-LS can easily be setup for automatic testing, so that any user can test a profile setting to see what results to expect in a particular environment. I strongly encourage this as a way to build confidence in your settings and to develop some sense of normal operation in that environment.

Today's test is here:
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Shawn Billings

Shawn Billings
5PLS
This is setup on one of my back property corners:

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This is straight overhead:

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Over the years I've tried to get a verified point on this corner and never been able to do so using GPS and Glonass alone. Today, within just a few minutes I had my first point and a few minutes more I had a second. So far, I've been running for about 2 hours and I have 7 points collected. That averages out to about 18 minutes per point, which in this environment is incredible. All seven points are within a few hundredths of each other with no bad points collected (so far) but the test continues, so we'll see if this holds up.

As you can see from the pictures, the challenge for this point isn't just the trees, but the type of trees: mostly pine. For whatever reason, as many of you have experienced, pine canopy is difficult for GNSS work. It has been possible for several years to work around a few scattered pine trees but a pine forest, such as this, is usually a dead end.

I'll keep working with different profile settings, but for this one, I've setup up with verify with V6 resets on, a confidence of 1, minimum engines 1, a minimum phase 1 duration of 180 seconds, minimum epochs 1, minimum duration 0, no validation. What does this mean in practice?

When the start button is initiated (either by the user or in this case, by auto start), phase 1 is started, waiting for a fix, logging that fixed epoch, then resetting the engine(s) that provided it and repeating. The minimum number of fixes in the group is 2 in order to satisfy the confidence of 1 (one fix gives a confidence of 0, a matching fix gives a confidence of 1). However, by setting the phase 1 duration to 180 seconds, the software remains in phase 1 even after achieving a confidence of 1 or more. Until the group has a duration of 180 seconds, the software will not move to phase 2. Once the software passes phase 1 (with 2 or more fixes and more than 180 seconds between those fixes) then it proceeds to phase 2 to get 1 epoch (the minimum required epochs). So, in theory, the point could store with only 3 epochs. While possible, it is unlikely this will happen very often. There will probably be several fixes in phase 1 that will fit in the group before the 180 seconds is acquired, so it could have several more epochs in the solution, but this test is less about building precision (which would happen with more epochs) and more about generating accuracy, i.e. reliable fixes, which from my experience only occurs with time - specifically the 180 second rule.

We'll check in on the test more and provide some detailed statistical analysis later on. But for now, I'm really pleased with what I'm seeing.
 

Sdrake14

Active Member
Do you think the Triumph-3 will lend itself well as a secondary backup rover? If so what configuration might work best ie: controler, software, etc.....?
 

Nate The Surveyor

Well-Known Member
What are your thoughts? I realize that the t3 has some differences when compared to a TLS. But, aside from those differences, would there be ANY performance difference between the new T3, and a second LS, on base?
If I got another LS, and had a job that was in the wide open, (no need for the additional sats), then I could run t2 on base, same radio, and run 2 rovers.
But, if I buy a T3, then I essentially have 2 bases, t2, and t3. And, I can't occasionally run 2 rovers, on the SAME job.
So, all things considered, would a second TLS be able to be my base, most of the time, and would it have the same performance, as a t3, sans the fact it can't broadcast 1 watt, like a t3, and a few other mechanical differences?
Thank you.
N
 

Shawn Billings

Shawn Billings
5PLS
Do you think the Triumph-3 will lend itself well as a secondary backup rover? If so what configuration might work best ie: controler, software, etc.....?

I don't have a good answer for you at the moment. It's on my list to play with options available. But I'd like to keep this thread focused on the Triumph-LS using multi-constellation corrections (which the Triumph-3 is providing in this case).
 

Shawn Billings

Shawn Billings
5PLS
At 4 hours and 18 minutes, I have 16 points stored. All are good fixes with a spread of about 0.2 foot (radius 0.10 foot). That's an average of 16 minutes per point. I think that is phenomenal in this environment.
 

Shawn Billings

Shawn Billings
5PLS
What are your thoughts? I realize that the t3 has some differences when compared to a TLS. But, aside from those differences, would there be ANY performance difference between the new T3, and a second LS, on base?
If I got another LS, and had a job that was in the wide open, (no need for the additional sats), then I could run t2 on base, same radio, and run 2 rovers.
But, if I buy a T3, then I essentially have 2 bases, t2, and t3. And, I can't occasionally run 2 rovers, on the SAME job.
So, all things considered, would a second TLS be able to be my base, most of the time, and would it have the same performance, as a t3, sans the fact it can't broadcast 1 watt, like a t3, and a few other mechanical differences?
Thank you.
N

There are several things to consider with that question. The Triumph-3 does track some signals that even the Triumph-LS does not tract (as I understand the situation). This means that the current Triumph-LS would not see a difference between T-3 or TLS base corrections, but the Triumph-LS Plus, which has the Triumph-3 chip would be able to use more signals (if those signals are in the correction stream) from the Triumph-3 than it would from the Triumph-LS. The other issue is that currently there is no way to use a Triumph-LS with an external base, such as the HPT435BT radio, not by Bluetooth, not by repeater. Furthermore, currently there is no way to use multi-signal messages (MSM) with our repeaters. It's too much bandwidth to squeeze into half a second. If you can get away with 1-watt output for your projects or using as static IP over cellular, I think the LS is compelling as a base for the reasons you mentioned (use it as a base or as a rover and it comes with multi-constellation already active).

I've never used two LS rovers on a single project working solo. I know Adam has. For stakeout, I can imagine it is compelling. But seeing the performance so far in my little test, I don't think I would want to use two rovers GPS+GLO only instead of one rover with GPS+GLO+GAL+BDU. But the guys who have that capability can speak to that question from experience instead of speculation, like me.
 

Nate The Surveyor

Well-Known Member
I was of the impression that we also send our current TLS in for an upgrade. (At a cost of around 5500$) would this make it a "Triumph-LS Plus"? Or not?
Thanks,
N
 

Shawn Billings

Shawn Billings
5PLS
And again, let's try to keep this thread focused on this test. We may need to refer back to it in the future and we won't want to wade through information that is not relevant. These are great questions, just better asked in a different thread.
 

Shawn Billings

Shawn Billings
5PLS
This test is with the Triumph-LS (not Plus version). The Plus upgrade adds more capability because of better processors and signal tracking, and yes, sending it in for the upgrade would make it a Triumph-LS Plus.
 

Shawn Billings

Shawn Billings
5PLS
I just shut the test down for the day. Run time was 6 hours with 22 points collected at an average of 1 point per 16 minutes. Very pleased. All were good, no outliers. Now to see how DPOS processes the data...
 

Shawn Billings

Shawn Billings
5PLS
Average of 22 Points:
Spread:
N: 0.114 ft
E: 0.135 ft
U: 0.434 ft

Given the location, DPOS gave pretty good results. Without digging too deep at the moment, the average occupation time was only 16 minutes, with 12 of 22 points giving results that matched the RTK (remember all RTK was in agreement). For such short observations in such a bad location, this seems to be an improvement in general performance with DPOS using GPS+Glonass only with similarly short observations and bad environments.

All in all, I'm very encouraged by today's test.

If possible, tomorrow, I'll set up the base and rover in the same places and run it again at generally the same time of day. This time I'll be testing Adam's observation that with two engines fixed in the 2 Engine GPS+GLO+GAL+BDU firmware always gives a correct fix, I'll see if I can get the same reliability as was seen today (100%) with a shorter average time per point (16min/point). To do this, I'll set verification off and validation off, with minimum required engines at 2 with 1 epoch. It seems like this would fly circles around today's settings, but getting two engines fixed simultaneously may prove to be a challenge.
 

Adam

Well-Known Member
5PLS
Average of 22 Points:
Spread:
N: 0.114 ft
E: 0.135 ft
U: 0.434 ft

Given the location, DPOS gave pretty good results. Without digging too deep at the moment, the average occupation time was only 16 minutes, with 12 of 22 points giving results that matched the RTK (remember all RTK was in agreement). For such short observations in such a bad location, this seems to be an improvement in general performance with DPOS using GPS+Glonass only with similarly short observations and bad environments.

All in all, I'm very encouraged by today's test.

If possible, tomorrow, I'll set up the base and rover in the same places and run it again at generally the same time of day. This time I'll be testing Adam's observation that with two engines fixed in the 2 Engine GPS+GLO+GAL+BDU firmware always gives a correct fix, I'll see if I can get the same reliability as was seen today (100%) with a shorter average time per point (16min/point). To do this, I'll set verification off and validation off, with minimum required engines at 2 with 1 epoch. It seems like this would fly circles around today's settings, but getting two engines fixed simultaneously may prove to be a challenge.
Shawn, I looked at Micheals receiver which is running the new gnss firmware 3.7.7.200306. It had 5 bad fixes out of 1000 get thru using the 2 engine fix settings. this is 99.5% correct shots. Please report what you get when you test it. 99.5% is really good but I have been seeing 100% and haven't been able to get it to lie. I have not tested with this brand new gnss firmware though. I plan on setting up and running the same test all day tomorrow unless something comes up.
 
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