Grid layout

David Staveley

New Member
Hi there,

As I'm a geophysicist rather than a land surveyor, I hope you don't mind me posting what is probably a really easy question. When doing a geophysics survey, I set out a number of 40x40m square grids, aligned to a sraight edge of a field to make the geophysics survey easier. What I used to do with the total station was put it on the baseline at the edge of the field, tell it that it was at 500E,500N, point it along the baseline, set the angle to something like 270 (west) and then go and find 460E,500N for the next point and so on.

I'm trying to do something similar with the Triumph-LS. The plan I came up with was to collect the point I would have occupied with the TS, stake out on the point I had just collected and then walk 120m away along the baseline, then do a Multiple Point Localization (Unknown) with one point as 500E,500N and the other as 380E,500N, then go and find the rest of the points.

The problem I came up against was with the 120m stakeout part, as the DTT was given in whole metres (0dp), which isn't good enough for the localization. I got out the TS to measure 120m and then did the localization, and all was well. Is there a simple way to show to 2dp how far away from a point you are, or is there a way to do the whole thing more simply, like with the TS?

Cheers
 

Shawn Billings

Shawn Billings
5PLS
I would likely use stake alignment for this task. Stations and offsets could be used to navigate to grid points. Also, a hidden feature in J-Field, you can press the action button (middle hardware button on the left side of the screen) and the white boxes expand giving constant three decimal place precision. Press the action button again to condense the white boxes.
 

Kelly Bellis

ME PLS 2099
5PLS
Have a look at JField's extensive CoGo options. You can achieve your goal in the field and on the fly in more than one way using CoGo including Offsets and Stake, Divide Line. You might also want to consider having a generic drawing file of x number of rows and columns with your whatever-meter matrix, import it into a project and then rotate it into alignment with that project's edge-of-field orientation.

I'm sure others will have some ideas to add to your list of options afforded through JField.
 

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Matt Johnson

Well-Known Member
5PLS
Stake Line would best be suited for easily creating grid points; however, it does need modified some as it currently does not create offset points for the line endpoints:

Cogo_20150525-10.28.47.png


I will request this feature be added.
 
Last edited:

David Staveley

New Member
Thankyou for all your replies!
The action button trick is excellent, that will get me going at least.
As a non-surveyor, all the cogo stuff is a bit beyond me at the moment. I definitely have to read up on that more.
Ideally, I would like something like Single Point Localization (Unknown), but a second point can be surveyed and assigned a direction from the original point, rather than having to work out what angle to manually change it to, so for example, the point may be 250 degrees from geodetic north in relation to the original point, but you are telling it that it is actually 270, so the grid would be rotated 20 degrees around the original point.
 

Matt Johnson

Well-Known Member
5PLS
Hi David, the Stake Line Cogo function has been improved and bugs have been fixed with it. It has also been renamed to Line Offsets. In the next update of J-Field you should see the improvements. Here is an example of how it can be used to create a 40x40m grid to the right of a line between points 1 and 2:

COGO-STAKEOUT-LINE_20150530-17.12.47.png


To preview the points that will be created tap the diagram:

Cogo_20150530-17.12.26.png


If you want to create the grid on the left side of the line between P1 and P2 you would simply change the offset from 40m to -40m.
 
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