LS and trajectory...

Hi Guys,

How many of you use 'trajectory' a lot for topographical surveys? I have had a little play with it but haven't had a job yet large or flat enough (hills in NZ are crazy!) to put it on the 4x4 and drive. What are you guys doing with finding out where you have already surveyed?

External antenna on the car and just keeping an eye on the screen in cab?

LS mounted close to the drivers window to keep an eye on it?

Javad mobile tools, on your phone or tablet?

Would like to know everyone is doing it and what the best way froward for us would be?

Thanks!

Blake
 

Adam

Well-Known Member
5PLS
Hi Blake, here are a couple of threads with some info about that. https://support.javad.com/index.php...y-settings-for-use-on-a-quad.1491/#post-12684
and https://support.javad.com/index.php?threads/topo-setup.1479/#post-12535. I have used the LS on top my utv for large topo's. I like to have a receiver on both sides
of the vehicle. This is to catch bad shots because in trajectory there is no verification or check, plus you are driving around sometimes next to treelines. The receiver on the
passenger I side I set to collect and never touch or even really look at it until i am finished. The receiver on the driver side is used to pick up detail like breaklines and such. I
use a data collector and the T2 on this side so I can have the collector mounted in front of me. The same can be done with RAMS and a tablet and the LS.
 
I'm assuming RAMS requires an internet connection over a cellular network, a lot of the places I work have patchy on no cellular network :(
 

Shawn Billings

Shawn Billings
5PLS
I'm pretty sure that the RAMS app will connect directly from cell phone to LS without the need for Internet or cell service. No need for a mobile router.
 

Matt Johnson

Well-Known Member
5PLS
I'm pretty sure that the RAMS app will connect directly from cell phone to LS without the need for Internet or cell service. No need for a mobile router.

The device and LS must be connected to the same network. Creating a mobile hotspot is an option but I don't think this is possible when mobile service isn't available, at least on iOS devices. Can an Android device create a hotspot/network without service?

Capture.PNG

https://play.google.com/store/apps/details?id=com.javad.ramsviewer&hl=en
 

Shawn Billings

Shawn Billings
5PLS
I'm not sure. I just know that the connection is (as the screen shot says) peer to peer, not requiring an internet connection for the data flow. I don't think you have to have a signal for the hotspot to be turned on with an Android device, but I could be wrong.
 

Darren Clemons

Well-Known Member
Hi Guys,

How many of you use 'trajectory' a lot for topographical surveys? I have had a little play with it but haven't had a job yet large or flat enough (hills in NZ are crazy!) to put it on the 4x4 and drive. What are you guys doing with finding out where you have already surveyed?

External antenna on the car and just keeping an eye on the screen in cab?

LS mounted close to the drivers window to keep an eye on it?

Javad mobile tools, on your phone or tablet?

Would like to know everyone is doing it and what the best way froward for us would be?

Thanks!

Blake
Blake,
I have done 3 or 4 good sized topo's with the LS. I'll have to admit it was quite a challenge for me to work with trajectories. The first one I did, I made a mess out of but it has gotten easier as I've gotten used to it.
I use RAMS and an Ipad so I can see the screen on it. While there are no points collected the trajectory lines do show up on the collect screen to help with keeping up with where you've been.

Depending on what's around you it may be difficult to hear the points store and more importantly when they stop storing on your specified distance you've set. I have a set of Bluetooth ear buds that I use to hear the LS while driving my 4 wheeler.
Also, I think there's a setting now that will cause the lower flashlight to flash every time a point is stored.

Adam's idea is very good, if you have two receivers, as you will undoubtedly collect some "bad" shots because, as he mentioned, there is no verify or validate while using trajectory. The last site I did, I collected almost 2500 points and had about 12-15 "bad fixes" in that entire collection so the percentage is very low but there will be some. I started off setting minimum engines to 4, but upped it to 5 after a while to eliminate most of them.

Shawn gave me some good tips on finding these errors such as, if you can, walk a few cross grid lines with the monopod after you drive the original grid to pick up several "check" points. Then, when doing the original topo in the office, draw it at about 0.1' or 0.2' intervals, that will magnify any/all points that are off and you can locate them and delete them
 

John Thompson

Well-Known Member
walk a few cross grid lines with the monopod after you drive the original grid to pick up several "check" points.

Is it possible to stake out individual trajectory points when doing check shots like this?

I had the wrong antenna height when I collected the trajectory. I would like to stake out a few points and correct the antenna height. Is there a way to do this?
 

John Thompson

Well-Known Member
I figured out how to show Trajectory Marks, and I collected a few shots with the monopole close to my ATV trajectory shots.

I would like to be able to inverse between them and adjust the antenna height of the trajectory. Is that possible?
 

Shawn Billings

Shawn Billings
5PLS
Not at present. The trajectory can be exported as an ascii text file, but currently you can not use the trajectory data in the field. It's a need.
 

Adam

Well-Known Member
5PLS
I figured out how to show Trajectory Marks, and I collected a few shots with the monopole close to my ATV trajectory shots.

I would like to be able to inverse between them and adjust the antenna height of the trajectory. Is that possible?

Hi John, I realize this is hindsight for you but I calibrate the height of the LS mounted to my UTV on a flat concrete surface with me setting in the seat. It's a little overkill but at least I know the height is correct. My height never changes for trajectory.
 

Darren Clemons

Well-Known Member
Not at present. The trajectory can be exported as an ascii text file, but currently you can not use the trajectory data in the field. It's a need.
Yes it most definitely is Shawn. I've done three or four with the LS and to put it nicely its "sticky". You can get it done, but on the fly collecting one epoch topo shots is not really what this LS is designed for. It goes against every other grain the software is built on not using any verify/validate.
Then having to export and renumber all the trajectories into cad points is not a joy either, but like I said it will get it done and I wouldn't trade this LS back for anything :)
I don't do many topo's anymore anyway as all of the county and city I live in, as well as many close by, have lidar flown 2' data that we most times just buy and use for design purposes.
 

Shawn Billings

Shawn Billings
5PLS
I don't worry with renumbering. If your cad package can handle alphanumeric point number, there isn't much reason, especially for trajectory points which probably won't be used outside of CAD for anything.
 

Darren Clemons

Well-Known Member
I don't worry with renumbering. If your cad package can handle alphanumeric point number, there isn't much reason, especially for trajectory points which probably won't be used outside of CAD for anything.
Very true Shawn. I'll try that next time. I'm just so used to and stuck on having point 1 through whatever in a nice neat order but you're right. As long as the node and elev is on screen it's all I need.
 

Adam

Well-Known Member
5PLS
Hi Blake, here is one i did a while back if you would like to get an idea of what you can do. I did 40 acres per day. I use two receivers, you can see the points about 4 feet spaced 10 or 20ft.
 

Attachments

  • TOPRAK SURFACE.zip
    15.5 MB · Views: 269

John Thompson

Well-Known Member
I recently did my first topo with the LS and my ATV. Actually, I did a short test topo of my yard first to make sure I had things set right, then did a real one on a job. Here are a few observations about how it went.

I mounted the LS on the front rack of my ATV. I can see it and reach it from the seat. The shot counter has nice big numbers so I can see when it takes a shot.

In the past when I've done this with my old system (SurvCE - Auto by Interval), I don't change the antenna height when I put the receiver on the ATV. I just keep track of which points are from the ATV and which are from the pole. Then when I'm done with the ATV, I put the receiver back on the pole and stake out several ATV shots, save them, and in the office, calculate the average elevation difference between ATV and pole, and adjust the ATV elevations. I get a double check on a few points that way, and I don't have to remember to change the antenna height and change it back. I don't always have a flat surface and an assistant available to measure like Adam mentioned, and I also figure that the ATV antenna height changes some with load, tire pressure, soil, etc., so that's the method I've chosen.

Hence my question above about staking individual trajectory points. I was able to use the map to get really close to several trajectory points using Collect instead of Stake, so that works fine. It might be nice to be able to inverse to individual trajectory points by selecting them from the map.

I like that the trajectory doesn't clutter the map with points.

I like it that the LS has memories for different antenna heights. It would sure be nice if I could attach a name or description to the antenna height, and if it would remember whether it is a slant or vertical height.

It would be nice to be able to adjust the antenna height of a trajectory in J-Field. The LS does a great job of shifting coordinates around every which way.

I also found out that M-Local does not move a trajectory. I had to apply the shift from my auto base to M-Local myself.

When I export points from a trajectory, it names them DefTag-1, DefTag-2, etc. Carlson Survey apparently has a 9-character limit to point names, so when I try to import DefTag-100, Carlson Survey chokes on it. So the first thing I tried was to change the name of the trajectory and re-export from J-Field. That didn't help, since the points aren't named the name of the trajectory. They're named the ShapeTag of the trajectory and I don't see how to change the ShapeTag of an existing trajectory.

Overall, I'm quite pleased with how it works. The more I use this machine, the more I like it. It keeps improving.
 

Mikhail Drakin

Developer
John, you can use "Seq.No" (sequence number) field to create any kind of name you want in CSV export: add either description or code, set secondary separator as None and use it to concatenate description or code with seq.no. Or use just sequence number alone.
 
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