Topography using UTV

Just my thoughts.

There is a suspension on an atv. There is your weight. Lots going on. Mount the antenna about head high, and roll on. Your Height of Rod will vary as you run. Braking, Accelerating. The whole 9 yards. If you need more accuracy, you can walk. Or, get an atv without suspension. It's something you will have to live with.

Or, if the slope is excessive, then you probably could walk it.

You get the idea.

N

The tilt isn't going to make much difference unless you are on extreme slopes.

We recently did a 75 acre topo with the GPS rover mounted to a 4-wheeler. We went back with the rod and checked a few shots. All were within 0.15'.

Thanks, Do you use the same rod height or somehow compensate. I am thinking I should mount the prism or gps directly above a tire to reduce rod height variations. Is there something similiar to a depth finder but for use on land and compatible with Carlson Surv CE?

Theoretically, mounting it in the MIDDLE of the ATV, will reduce all the bumps, or average them, to the collective bounce of the whole machine. So, I mounted mine just right of the headlight. So I could see if I was going to hit a branch, etc. Don't forget to get a fiberglass antenna, to catch cob webs!

NOTHING like a face full of fresh spider web, at 8:00 in the morning, with a spider RUNNING for his (her) life. And looking for a dark place to hide! (Sorry, I digress!)

N

I've used ATV's and had good luck. I also mount the unit toward the middle of the ATV. On farm ground or pasture, its always worked well. The only special care I take it to make sure I'm on the ATV to measure the rod height while I'm on the ATV and make sure I'm not to far forward or towards the back of the seat, in other words sitting in the location I would be when driving it. Its also best not to go to fast, maybe jogging type speed.

Here is how I have mine mounted on my Ranger. I keep mine on the driver side so its easier to drive along the edge of a breakline. For an HI, I measure while I am sitting in the seat. I will also locate a point on flat ground with my normal pole, then move the receiver to the ranger and drive over the point and stake it out. This is a good check of your HI, the cut/fill should be 0.00. I have topo'd a lot of pastures and cultivated fields with this method. You need to drive slow, I normally stay around 3-5 mph depending on terrain. Afterwards stake a few points out and see how close they are matching.

I've done lots of topo surveys with both my GPS and my robot prism. Works like a champ. As pointed out, the HR is variable so never expect anything closer than a few tenths. But if that's all you need, then that is golden.

It works really good for linear features. I have my receiver directly over my right front tire, and as I recall the HR is set to 4.3 after I set my sturdy torso on it. If it tips, then so be it. Swerving to avoid a chuck hole, dead possum, jogger, or other things will throw things off, but you can get around that with the push of a button.

Open field topo is a bit more scope related. Two ft contours, I wouldn't hesitate. One ft I'd be inclined to do some hard field checks by removing said receiver and taking a shot with a firm HR. Then continue as before.

One thing to remember is that it is a one time time stamp of your shot. If you want a 75 ft grid, set your distance interval to 65 and you may get 75. DRIVE SLOW, the slower the better. My ATV never leaves 1st gear in fields, but will hit 2nd on linear features.

I would love to work in an area that this would be a possibility.

Too many dern trees up here.

Yes, atv mount and truck mount, do a simple 40 acre field in about an hour. No problems with the hi. Get it mounted, measure it and do some testing, you will probably be surprised how accurate it is.

You can lose some accuracy per shot, but usually the increase of overall shots makes for a prettier topo - and can show undulations and detail that "increase" the overall accuracy. Similar to aerial photogrammetry...

The best thing, also, is to go over everything twice - that will show if anything goes outside of allowable accuracy. or dual grid pattern...

Thanks folks, for the helpful info. I will be trying my rig out soon.:-)