What is the cheapest option to create elevation maps of the entire farm? I haven't kept up with the Agopen GPS /opengrade/RTK etc. Is that now a capability at a reasonable price, then just drive a grid with a quad?

I can find bits and pieces of accurate Lidar or similar data for free for some areas, but never have found any for my area. Buying it would add up in a hurry. Has anyone found a source that covers this area(Clearwater County in Central AB)

What about drones, how cost effective would it be to buy the drone and the hardware and programs to do it that way?

Any other options?

I guess the next logical question is what will you be using the maps for and in what data format? Compatibility with other software?

 

At this point, I just want maps I can look at to establish slopes and low points to make future plans. Ideally be able to draw a path such as google earth allows and follow the contours. I don't currently have any equipment set up to use the info. I check elevations with rotary level, then I work freehand then verify with rotary laser level.

 

there isn't anything that will give you 'useful' data, and is super cheap ..
you really need rtk to make it useful, because vertical heights are poor with waas, and that does cost ..
lidar is an option, but rtk and doing a grid with your quad, or tractor while you are doing some seeding, or whatever, is a much better choice ...
especially if you are thinking of using it for drainage ..

 

The data you seek is here:
https://www.altalis.com

 

The data you seek is here:
https://www.altalis.com

A 25m Dem isn't gonna cut it for drainage, unless i missed where accurate maps are on the site.

 

I guessed you missed all the Lidar data then.

 

Still only 15 m. They don't specify the grid for Lidar, but probably pretty poor for grade work.

 

This probably doesn't do you any good seeing as you're asking the question, but, I know my Ag Leader stuff plots elevation automatically as I travel a field. Kinda interesting sometimes to overlay a yield map on a elevation map. I only bring this up thinking you may already have some elevation data logged without knowing it.

 

I think the problem is as Warren (@wvca) is saying accuracy from WAAS isn’t good enough for drainage design etc. ie it’ll give you an indication, but not suitable for surveying and planning.

 

Don’t know if you have any Trimble GPS stuff but the Trimble i use in the red headers records data for elevation maps. Looks Good enough for general ideas and farm planning. Iam sure if someone played with the settings it could be more accurate. I don’t know. I just saw the option in layers once while I was snooping around on The AFS programme. The contour map looked pretty good to me when I briefly converted it.

 

I have experimented with the non RTK data that regular GPS is providing, and it isn't accurate enough to be useful for anything. Just sitting still, it will vary many feet in elevation. We have very little grade to work with, so need data to be quite accurate.

I suppose the better question should have been, is how affordable is it to get AgopenGPS set up for RTK, and how functional is the resulting data?

I hadn't checked Altalis for quite a while. I can't see a 15m grid being good for anything except very crude planning. I'll try downloading the sample data for the $440 per sq km LIDAR data and see what the resolution is.

 

I hadn't checked Altalis for quite a while. I can't see a 15m grid being good for anything except very crude planning. I'll try downloading the sample data for the $440 per sq km LIDAR data and see what the resolution is.

Roughly the price of a cm accurate RTK from Ublox.

 

Print a high res sat map of the quarter then head out with your rotary laser setup in the middle then jump on the quad and take some measurements and write them on the printed map. That’s going to give you a good idea where water will go and if it will for nothing.

 

We mapped a couple of fields this spring with Green Aerotech. I'm not totally sure what the X/Y resolution is, but they measured some pretty small features (ditches) that a previous mapping by a ground-based rig didn't even register. They have a fixed-wing UAV that they fly in a grid pattern, and then use multiple images to create parallax which they can determine ground elevation with. It's pretty remarkable how well it works with a single camera.

They have an online tool for identifying drainage channels and showing you what your cuts would be like. They claim their elevations are accurate to within a few cm. I think they can export data to a shapefile, so drainage software packages should be able to work with it.

One of the problems with trying to get elevation data from your sprayer, tractor, or combine--even with RTK--is that you really only get data every so often depending on your width. But could give you some baseline measurements.

Another challenge is combine data from different sources. Even with RTK, it's best to think of your data as relative. Unless all the RTK systems are calibrated with known survey markers, they may disagree with each other (but in consistent ways). Just something to consider if you ever import data from different sources into a GIS editing program.

I want to set up a mobile RTK unit using a ZED-F9P that can talk to my phone over bluetooth. Battery to run the ZED and the radio receiver, plus a bluetooth serial adapter to get the NMEA feed to my phone. Then I could use a logging program (something like Mobile Topographer Pro) to collect data. In many cases I know where the drainage needs to go, but I don't know exactly how much needs to be cut in different places. With the mobile gear i could drive a quad through the bottom of the area and get some very specific data to play with that way.

 

Trimble centerpoint was $1200/year/device a few years ago. horizontal is capable of inch accuracy. Not sure vertical. If there is RTK service in your area it may be worth it. I doubt anything cheap would close enough. Sounds like you need within a few inches or less? Never done drainage. Do drainage rippers have RTK type service on them to keep grade?

 

I doubt anything cheap would close enough. Sounds like you need within a few inches or less?

Price isn't the qualifier for accuracy. Few hundred bucks today gets you full RTK cm precision, no unlocks, no fees, no subscriptions.

 

While RTK has made some significant advances in both higher precision and lower cost , the standard is still a dual slope laser with laser controlled machinery .. It just works with much higher accuracy on the vertical, which is where you need it ..
It's why I bought the laser head I do have, if it matters, it's a Spectra....

 

Good god. I wouldn't go back to laser for no money. Might have been the standard in the 90's.

 

Still is, higher accuracy on the vertical...

 

It's not even a comparison. Used to do do leveling with a laser and your stuck in 2D and single planes or if you actually adjusting for planes your spending so much time fooling around and not actually working. GPS Multiplane and curvature of the earth cuts have saved me thousands in earth moving costs vs doing the same work with a laser.

Sure it's more accurate but the difference is pointless.

 

How about the grade control or software design solution? Seen in another thread you were working on it. A fancy map is nice but nothing like the full meal deal doing steering and guidance following a design while your sipping your coffee catching up on combine forum.

 

On my long list of projects is to build a simple arduino (or more likely MicroPython) program to do simple grading. Basically you set a start point and a slope, and then as you move along, the receiver mounted to the blade will trigger a hydraulic block to move the blade up or down to hold that slope. It could be as simple or as fancy as one desired. For most applications a simple princess auto solenoid valve block with the hydraulics turned way down (no PWM) would work well enough. Could be adapted to trenchers as well to hold a slope.

 

Open Grade is still on github. Works well, a few catskinners have been using it. Once you're made your grade pass, the rest of the sides are very easy to do. RTK mounted right on the blade.



https://github.com/farmerbriantee/OpenGrade

 

digital elevation model

Do not use gps data : it won' t make it

i did it : no way
Solution is sar interferometry
free and available all over the world

 

Do not use gps data : it won' t make it

i did it : no way
Solution is sar interferometry
free and available all over the world

I know nothing about that ... how do i get it here in sask, and will it do sub cm elevation, on say a 3 meter grid ??

 

Noticed Open Grade was mentioned here. Just wanted to say it works great with swiftnav piksi RTK GPS. We have it running in a D8L and D5H. Used mostly for building terraces would work great for building pads. Its hard to believe that a simple hydraulic valve would take it to fully automatic.

 

I tried purchasing the Lidar15 DEM data for a township. All but 2 of my quarters land in that township, so it is cheap enough to try.

Not knowing which format was what, I choose the .xyz format, as opposed to the ESRI. With the poor logic that xyz would give me 3d coordinates that would be easy to overlay on a map.
Now I haven't found a free way to open the .xyz Did I choose the wrong type? Anyone know an easy way to make that file type useful? Waiting for a call back from AltaLIS.

 

Apparently QGIS can import those files and convert them to other things. There are some google hits on this topic anyway.

 

I can put them on a map for you if you like, it only takes about 2 minutes.

Marg at AltaLIS is usually super helpful if you email them. Just tell her you got the wrong format and she'll usually send you the right one.

 

I did download the QGIS this morning, took a while, just came back and got it installed, have a very nice map now, but don't see any way to read the elevations off of it. Can even see the boundaries of most properties thanks to roads and ridges around fields, so don't even need to overlay a map. I attached a snip of the program, what option am I missing to get elevations to show up numerically?