Why would you not recomend sessions over 7 minutes?

[Nate The Surveyor]

Here is my logic:
Its a real bad place to get a shot. After sitting on it for 1 minute, I get one click. One epoch. I stay there for another 30 minutes. It's got 12 buckets. And, finally it gets one click that agrees with that click at one minute. Now, that's pretty confident that it's right. At 35 minutes, and at one more click, and 18 buckets. So, we now have 3 in agreement, over 35 minutes. Now, I save it. Point 120. Start second observation. In 3 minutes, it has 3 clicks, and dist to last is 0.05'.
So, I now know that 120, and 121 are fundamentally in agreement. I let it sit for 15 more minutes. Where it finally get to phase 2, and then gets to 120 clicks, at the 20 minute mark. I save it, skipping phase 3, because point 120 tells us it's the right point. 3rd observation, and in 10 minutes, it's all the way to 120 epochs. Now I've got 3 observations, all within a tenth, and I've got it.
Anyway, I'm ALWAYS going to be pushing this equipment. As far as it will go. Another thing, is RTPK. At a certain point, it takes it a whole minute to process. You never know if it is in agreement, because it immediately begins next RTPK. It needs a delay between RTPK, with a way to tell how many RTPK observations it's made, and how many were in agreement with each other. Like if RTPK 1, RTPK 3, and RTPK 10 are all 3 in agreement, (by some tolerance amount) I'd like to store that point. The average of those 3. And to know their shot spread.
I know I'm rambling. But my t3 is not here yet....
Nate

 

[Nate The Surveyor]

More concise:
When a place is so bad, it can only get a good click with reset, every 5 minutes, I want to stay on it a long time.
And, I want RTPK to cooperate, as well.
Nate

 

[Matt Johnson]

In areas where RTK does not produce solutions RTPK sessions in agreement with time separation are needed. My current recommendation to verify a solution with RTPK is to have 6 minutes of time separation between sessions that agree. For the standard LS I recommended 90 second sessions. To get the time separation you will a RTPK Verification Level of 6 (4 x 90s = 6 minutes).

To stop surveying the point when this is met you should check "Stop Survey When RTPK Solution is Verified".

You can press the "Stop RTPK" white box button to stop the processing and see the current status if you want to but sometimes this does not work if gets very backed up. Be sure to select and prefer the RTPK solution and not the RTK solution once verified through RPTK.

For the LS+ I currently recommend 30 second session so to get 6 minutes of time separation with it you will need a RTPK Verification Level of 14.

These recommendations are the result of a test I have been running in a very bad location near the Javad Headquarters in San Jose with the building acting as a large reflecting surface and a tree directly above the antenna.

This tree now has leaves on it since this photo was taken.

 

[nusouthsc]

Where is the option to set the verification level? And I am assuming some of these settings are pre-release?

 

[Matt Johnson]

Yes this option is in the PreRelease version.

 

[Nate The Surveyor]

Thank you.
I still think we need a way to take shots in really really bad places. I can see wanting to leave it out for several hours.
In fact, I was doing this with locus 8 channel gps L-1 only. Long ago. I think 36 hours is my longest observation to date, using Locus. And, I got that shot. I later verified it with total station, and 2 nails in the clear. They matched within 0.01'
I'm confident that we either need wide open spots to work, or enough TIME.
Nate

 

[Nate The Surveyor]

areas where RTK does not produce solutions RTPK sessions in agreement with time separation are needed. My current recommendation to verify a solution with RTPK is to have 6 minutes of time separation between sessions that agree

And, what I'm saying is automate this process, for the sheer value of this.
I'm for it.
N

 

[Matt Johnson]

I still think we need a way to take shots in really really bad places.

This is exactly what I described. In the location shown above most points do not have more than 10 RTK epochs before it is verified with RTPK. With this method you can expect 95% of the points to be horizontally within 0.15' of the average. To get better precision you can occupy the point longer and average many points together. There is a 100mb file size limit in RTPK so no longer than 4 hours per point when using 4 constellations.

And, what I'm saying is automate this process, for the sheer value of this.

It already is automated. You press start and wait for it to display Accept/Reject or you can turn on Auto Accept and Auto Re-Start and automatically collect many points to average.

 

[Nate The Surveyor]

I'm champing at the bit, to get my T3, and LS plus.
It's absolutely fact that we often drive an ATV into some far and forsaken place, then park and walk for 1/2 hr, and take some shots in impossible places. We want, need, and depend on equipment that can do it. We are surveyors. I'm one of the slower persons, intellectualy. So, I'll be excited to try it.
But, I'll be running T3 and old LS for a few months first.
Thank you,
Nate

 

[Nate The Surveyor]

I guess what I'm thinking about is on the one hand you are saying: don't go over 6 minutes, and on the other hand, it's designed to get these impossible shots, that may take longer than that. Trying to get my mind wrapped around it.
Nate

 

[Matt Johnson]

I said there needs to be a minimum of 6 minutes of time separation between the first and last session that agree. With these settings in that location points are averaging 24 minute observations before being accepted.

 

[Nate The Surveyor]

I'll be eager to try it, when it arrives!
Nate

 

[Matt Johnson]

You can try it now with the T2 base and standard LS. Having a T3 with more signals and constellations will definitely help but for RTPK there isn’t much difference between the LS and LS+.

 

[Nate The Surveyor]

Ok, so you are saying that this version of RTPK is good for, say a 30 minute observation, if need be?
Remember. My whole original question was about time. Time over 7 minutes.
Could I set it up with RTPK, auto store, and auto restart, and perhaps get 3-4 shots per hour, and collect points that generally agree with each other by some 0.15'?
Is this designed for potential 1 hour observations? Thank you

 

[Matt Johnson]

It can process files up to 100mb in size which is about 4.5 hours of data with 4 constellations.

The 0.15’ value I mentioned was the difference from the averaged coordinate of many points so for 2 points there could potentially be a spread between them of double that amount.

 

[Nate The Surveyor]

Ok, another question.
When you do a shot, that must be interrupted, and you press STOP, walk off the road, then put it back, and press RESUME, what happens in the LS?
I conjecture that it either has to stop, and start a new file, or that it simply flags part of the file not to use.
But, what does it really do, and what kind of affect does it have?
Thank you.
Nate

 

[Shawn Billings]

Still one file but no data during the pause is recorded.

 

[Nate The Surveyor]

So, let's get back to the original question. And the answer:
It appears that RTPK is designed for up to 4-1/2 hrs per session. I go some pretty wooly places. Last year, I spent 1-1/2 hrs on one point, in some pines. I then came back, and spent another 1-1/2 hrs. On it. I was doing my own study of the "outer limits". I think this is the worst place I've been to date.
I feel I've gotten it +- a tenth of a foot. It's got several outliers. I'm one of these guys who wants to know.
Fact in retrospect about that point above, the satellite geometry was poor during both 1-1/2 HR sessions. Mission planning would have solved it in much less time. I'd like to see mission planning in the LS. I'd like to see it where we can look at it, at any time, and decide to "get this point between 1:00 and 1:30". Or go to the wide open during this time.
Understanding our equipment, and all the potential factors is one of our jobs.
Thank you,
Nate

 

[Matt Johnson]

Mission planning would have solved it in much less time. I'd like to see mission planning in the LS.

I don’t think mission planning has much benefit and use now that there are four mature constellations that we can use. The total number of satellites does not vary a lot throughout the day. If you want this there are a number of free apps that provide mission planning.

 

[Nate The Surveyor]

Ok, I'll go along with that..... Unless you have ONLY 2 CONSTELLATIONS. And, I can get an app for that.
Got it. Thanks
N