RTPK

I am using an LS with T2 and RTPK.

Most of the work I am doing is topo.
stop after 10 epochs
only fixed
Verify 2 with/out reset

RTPK hor resid 0.131
Vert 0.23
Min rtpk verification level 3

It's routine for my PPK column to -18 N, -2 E, +19 U
Of course I get my share of sub 1 ft differentials. What is consistent about this is that there consistently isn't anything that I recognize as consistent.

Please tell me something is set incorrectly

As always, your help is greatly appreciated.

Well, Jim, is the project in the wide open? Or in the woods?
N

Mostly open

The settings you listed, would NOT be good, under a tree, or obstruction.
An extra little time per shot, gives strong certainty.
N

Thanks Nate, so you are saying the settings are correct except time per point? Since my work is primarily topographic in nature, I want the lowest time per point that will provide accurate, repeatable results.

Any idea on min time when NOT in the open?

In the open, for quick topo, I ignore or turn off rtpk. rtpk doesn't do well with less than 30 seconds and even a bit of cover need 60 seconds or more. I would turn off rtpk, change rtk to verify with reset, name the profile open topo. create a different profile some canopy topo and another full canopy. It's easy to switch between profiles rather than settings in a particular profile. Have to experiment a bit in your area, but for instance in wide open if clicking away fixed on 2 engines for 5 seconds I would want a reset verify 1 or 2 and move on, 10 second shot or less and rtpk might or might not get a solution or one that will agree. Get toward edge of field where start to see only one fixed engine, then switch to a more careful/longer duration profile with maybe a rtpk in the mix.

Duane Frymire said:

rtpk doesn't do well with less than 30 seconds

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Why do you say this? My tests show that the post processed solutions are always better than RTK. Here are the statistics for post processed solutions averaging 11.42 seconds per point in the open.

Matt Johnson said:

Why do you say this? My tests show that the post processed solutions are always better than RTK. Here are the statistics for post processed solutions averaging 11.42 seconds per point in the open.

View attachment 13075

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How far away was your base?

This was with the base 3’ away from the LS, obviously you should expect the precision and accuracy to decrease as the baseline increases.

Matt:

Where do you access your "Survey Statistics" report? Is it somewhere on the LS?

I think the difference is what we consider wide open, mostly open, etc. The differences Jim is getting are what lead to my answer. In my experience the rtpk needs longer than rtk to get a reliable position if open is not really, really wide open.

Matt Johnson said:

you should expect the precision and accuracy to decrease as the baseline increases.

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I was just informed that there was an RTPK test done and it didn't show a decrease of accuracy in a range of 0-10 km. The test had 1 rover and 2 bases. The 1st base was stationary at 30 meters from rover. The 2nd base jumps every hour to baseline lengths of 1,2,3,5,8,10 km away. The rover was in heavy canopy. The time was aligned for the intervals for both bases and the data was processed RTPKa. Statistics of solutions were exactly the same for both.

Glen Yasharian said:

Matt:

Where do you access your "Survey Statistics" report? Is it somewhere on the LS?

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This is from the "Statistics" option found in the menu of the points screen. To use it the Distance Filter must be enabled and it will compute the statistics from the point in the distance filter. In tests or repeated observations you would need to create an averaged point and then select it in the distance filter.

So RTPK relies on a steady data link with the base, if that link is lost are you still able to collect the data at the rover end and post process later with the same accuracy? Would this be done on the LS+ after the base is downloaded or would you need additional software?

RTPK stores the RTCM cotrections and then statically post processes the data. If there aren't corrections then the data could be post processed with DPOS after the base data is downloaded.

It seems the base should be able to store the RTCM corrections or can they be recreated from the rinex file

The base can store the data. It is stored as a jps file when this option is enabled and then the base/rover vectors can be processed with DPOS.

Matt Johnson said:

Why do you say this? My tests show that the post processed solutions are always better than RTK. Here are the statistics for post processed solutions averaging 11.42 seconds per point in the open.

View attachment 13075

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Matt,
in addition to rtk/rtpk giant delta, I ran into a situation on a site Friday where the base could not generate an auto position. So I was dead in the water, thinking that a setting was off.

unfortunately, before I realized the base was in a bad area I had made a number of changes all over the system, trying frantically to get the survey started. I don’t even want to set up tomorrow knowing the hassle it’s going to be unwinding my changes.

where can I find the basic settings for each category in set up, so I can verify all is set properly.
please tell me this information exists.

secondly, 10 seconds is not getting proper solutions. What I would like to have is a profile for precise topo in open, moderate cover and extreme cover.

i am using the ls and t2 and would like to set up the max constellations on the T2. There was a forum post on this a while back but it wasn’t easy to follow all the necessary changes.

I know this is a tremendous request. I am thinking the info must be avail somewhere so that we can easily recover from a screwup and/or set up our equip for optimal use without having to meet with support individually.

anyone else, please feel free to comment.
thanks for any help you can provide.

Jim Campi said:

where the base could not generate an auto position.

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Really? I'd like a pic of that base site.
For base site selection, pick places that have 100% open sky. I like a bald man's head. Up high, no obstructions.
I only use 80% to 100% open sky for a base site.
The more obstruction, the less performance.
N

Jim Campi said:

where can I find the basic settings for each category in set up, so I can verify all is set properly.
please tell me this information exists.

Click to expand...

You can reset the setting to the factory defaults in the System > Restore menu.

Jim Campi said:

i am using the ls and t2 and would like to set up the max constellations on the T2.

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The instrctutions to enable Galileo E1 and BeiDou B1 are in https://support.javad.com/index.php?threads/good-news.4294/#post-39769