A while back, I reported about using the MM CE to mark some lines for clearing purposes - using an external antenae.

Over the weekend, I went out and set stakes on centerline of the proposed roadway. As I was going, I would find a piece of the clearing flagging periodically still on a tree.

So far, the worst one out has been 6 feet. So, you would not want to mark a property line with it. However, it can be very beneficial for times when less accuracy may be acceptable.

Jon

We just staked a couple thousand feet of clearing and grubbing area with our PM3, with external antenna. Lots of curves, and really nice area with mild canopy conditions. We're expecting it to be really good for the purpose.

We have another project for the same developer that should have been ordered "two weeks ago", that we will do the same way.

No reason to run conventional stuff that will be blown out by the track hoe anyway

cool stuff :-)

jd

Can a Promark 3 be used for this purpose, or would it be too difficult a task for it?

quote myself:

"We just staked a couple thousand feet of clearing and grubbing area with our PM3, with external antenna."

Oops! I skimmed right over that. Thanks. Chris

I think that the PM3 would work admirably, especially if you had a begining point with good coordinates and "adjusted" the point to match the PM3 for that time & place.

I used the PM3 "autonomusly(or . . . psuedo-autonomously) for "pre-setting" points for setting pins.

Half a dozen points in a big field and each point missed my SE 11 feet. I think that had I compared it to the control point(on site) and adjusted for the difference, I would've been with a foot or so with instantaneous(almost) readings. That is, I didn't spend more than a minute on point.

The area I worked in today had less tree cover when marked initially than the area from my earlier post. Todays results were within a couple of feet.

Just to clarify the procedures I used in case anyone tries it and says I misrepresented the capabilities -

The project was established based on much control that was developed by a static network tied to a HARN monument and reduced in Solutions to state plane. The entire file thus far is in state plane. I uploaded all the data and the state plane projection file into the mobile mapper. The marking was accomplished by zooming in to a scale of 1"=5' to 1"=15'. Looking at the location pointer and its relation to the uploaded cad lines, flagging was tied on trees with the expectation of being +/-15' of line. So far, the results have far surpassed my expectations.

Not quite as good results with my MMCE.
First thing is you cant stake a line with it, it "goes to" midpoint of line. In ACAD I set nodes on the line then exported a shp file into arcpad (oh that word again). Staked(or went to) the points. In open areas it was within a couple of feet. Along a line with heavy canopy to the west it was 6'-10' off. In woods that I wouldn't have considered heavy canopy(oaks, poplars w/o leaves) forget it. Tried to "go to" a point , moved the approx dist and dir. and was 12'-15' back towards where I just left. Never could get anything I felt comfortable with. All this was checked with total station. I did not have an external antenae which I am sure would have helped but don't know how much.

Jon If I tried the scale work around like you did the thing would have constantly regenerated the view so as not to show the line at all.
I guess even in the woods I probally would have been able to get within 10'-15' of the line but I was really hoping for better than that.
Try setting points on the line. The MMCE will tell you dist & dir to the point.
Hopefully Carlson will have their software ready for the MMCE soon and I wont have to work with arc-anything.

While reconning for a corner in very similar canopy conditions as what I have discussed marking the line in, I happened upon an existing iron pin. I grabbed a fairly straight stick and used it as a plumbing pole. Using the internal antenae and a five minute observation, the coordinates where 17' from a static observation, with the PM2s, ran at a later date. Just from that one observation, I would guess that the external antenae adds a lot to what kind of accuracy you could expect.

When I get a chance, I will occupy a few of the points I have already posted comparisons using the internal antenae to static data. Maybe that will give a better idea of the benefits of an external antenae.
Modified By Jon Payne on 3/2/2006 at 10:08 PM

I think I notice some difference in procedures when it comes to using shape files for recon or rough stake out.

When we staked the roads for clearing and grubbing recently, we used 50 foot stations on our designed stations as tagged points on the designed center line. We staked to each and every 50 foot station as well as P.C.'s and P.T.'s of the curves. We had enough points in the clear areas that were very near the 1-2 meter range (if not sub-meter) to easily visually correct those that may have been a bit more problematic. After running through the center line and making adjustments, we pulled 40 feet each way and set stakes for the machine operators. The individual station points work as any other pre-set way point for doing a "go-to". Really slick tool.

(again, we are using the PM3, and not the MMCE, but I believe this routine and precision of use would be much the same)

jd