PreRelease 4.0

giulio

Member
how do the AFCL 90 95 99.5% values affect the possibility of fixing and its reliability? What value is best set for the various engines? Another thing I do not understand because I have epochs with fixes, in the various groups, even 5 and more meters away, I was used to the old instrument which was either fix (and in case it really was) or it was float.
fix.JPG
 

Nate The Surveyor

Well-Known Member
@Guilio
The key element to understand is: the GPS engine thinks they are BOTH good, that is, it cannot figure out what's bad. So, by sheer horsepower, it re-does it, and re-does it (various groups), until one group statisticly stands out, then runs with that group. This in a central way is what sets the javad system apart from the crowd. It can solve its own riddles.
Think in terms of a jig saw puzzle. It just keeps re-doing it, until the RIGHT piece falls in place.
I don't know of any other company addressing this factor.
In high multipath environment, with any other brand, you have to redo shots manually, until you get the consistency needed, whereas javad does this for you.
Nate
 

giulio

Member
Yes I understand that it is a totally different approach than the other brands., let's say that all are collected (verie false fixings) and then statistically these are discarded keeping the most probable one. But how are these fixings differentiated from floats?
Another question: how do acfl settings affect solutions and what values are recommended to set in canopy
 

Shawn Billings - Javad

Active Member
JAVAD GNSS
For a standard LS use Medium (99.5%), for an LS Plus use Extra Low (90%).
These settings determine the required statistical likelihood of a "fixed" solution from the contrast ratio. The contrast ratio is represented by the bar in each engine on the engine screen and is basically how much statistical information is pointing to a particular cycle (whole integers of the signal). For example is the number of cycles 100, 101, or 102. The contrast ratio shows the prevalence of one of those potential number of cycles.

For some reason, I don't understand, the Triumph-LS and the Triumph-LS Plus perform with similar numbers of good/bad fixes in canopy when configured at 99.5% for the standard and 90% for the plus.
 

Nate The Surveyor

Well-Known Member
how do acfl settings affect solutions and what values are recommended to set in canopy
I'm dummer than I look, especially if I accidentally look smart. I don't know what acfl means.
In the wide open, it's going to be pretty good, all the time. (Unless something is wrong)
In the woods, you must let it chew through all the extraneous data, to get enough good data, to statisticaly call it good. Within some tolerance.
N
 

Larry Alba

New Member
If Localization is available as a hard button I see no need for it on the Home screen. I'm with Jim.
Hi John,
Do you know how to do multipoint localization?
The youtube movie done by Shawn Billings is outdated.

I work on 30-Acre blocks that are 2700 feet x 484 feet.
Each lot is 180 feet x 242 feet.
There are four water pipes to designate the NW, SW, NE, SE corners of the block.
There are buried wood hubs on the lots that I must trace down, so I can put in fence posts.

Did you figure how to do this procedure in 4.0 software?
 

John Thompson

Well-Known Member
Hi, Larry.
I just watched Shawn's video again and I didn't see much that was outdated. Some of the buttons have been moved, but the concept is the same. The localization button is now inside Coordinate Systems.

The main difference between how I use localization and how Shawn shows it in the video is that I usually import my design points as a dxf file and then I add them to the localization by picking them from the map instead of from a list. In your case, the dxf file would look something like this.
30 acre block.png


When you import the dxf, J-Field creates points at each of the lot and block corners. Go find the pipes at the block corners, associate the corner points of the dxf file to the pipe shots, check the residuals and localization parameters, save the localization, stake out the lot corners, and start digging for wood hubs.

Does that answer your question?
 

Larry Alba

New Member
This sounds good. Since I am a beginner with the Triumph LS, will you please walk me through your lesson, with screen shots.
Here is a tiny block sample with 48 points starting with # 1 5000-5000.
larryalba@yahoo.com
Hi, Larry.
I just watched Shawn's video again and I didn't see much that was outdated. Some of the buttons have been moved, but the concept is the same. The localization button is now inside Coordinate Systems.

The main difference between how I use localization and how Shawn shows it in the video is that I usually import my design points as a dxf file and then I add them to the localization by picking them from the map instead of from a list. In your case, the dxf file would look something like this. View attachment 12951

When you import the dxf, J-Field creates points at each of the lot and block corners. Go find the pipes at the block corners, associate the corner points of the dxf file to the pipe shots, check the residuals and localization parameters, save the localization, stake out the lot corners, and start digging for wood hubs.

Does that answer your question?
I am a beginner with the LS.
 

Attachments

  • 20220913_063718.jpg
    20220913_063718.jpg
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For a standard LS use Medium (99.5%), for an LS Plus use Extra Low (90%).
These settings determine the required statistical likelihood of a "fixed" solution from the contrast ratio. The contrast ratio is represented by the bar in each engine on the engine screen and is basically how much statistical information is pointing to a particular cycle (whole integers of the signal). For example is the number of cycles 100, 101, or 102. The contrast ratio shows the prevalence of one of those potential number of cycles.

For some reason, I don't understand, the Triumph-LS and the Triumph-LS Plus perform with similar numbers of good/bad fixes in canopy when configured at 99.5% for the standard and 90% for the plus.
Shawn, I came across your post about setting AFCL to Extra Low (90%) if using a LS+. Does this advice still apply? Both of our LS+ units are set to AFCL Medium (99.5%). Will changing them to Extra Low result in better/quicker fixes without noticeable degradation of accuracy? Thanks.
 

Shawn Billings

Shawn Billings
5PLS
Shawn, I came across your post about setting AFCL to Extra Low (90%) if using a LS+. Does this advice still apply? Both of our LS+ units are set to AFCL Medium (99.5%). Will changing them to Extra Low result in better/quicker fixes without noticeable degradation of accuracy? Thanks.
Yes, provided that you use the variety counter to prove your fixes are good.
 
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