Point of Beginning

The Lawton Blog (pictures)

May 15, 2009

Posted By Deral at Home on 5/14/2009 at 6:06 PM

Ho hum. Another cloudy day in Lawton with a ton of GIS work to be done. I was getting into the zone on the computer while Michael was busy doing some research on several sections corners east of town that will be part of our Nine Mile Sewer project.

I think Michael knew that I was restless as he said "You know. I think I've about done all I can on research. I think it's time to go find these and shoot them into our database of cadastral information"..

Well, about five minutes later I had changed to field boots and we were in the van traveling east. Guess it doesn't take much to get me out of the office. Rain or not.

Michael's plan was to set up on one of our aerial target markers (5/8" x 30" with cap) to use for our base point. We found this pin missing the cap and it looked like it was bent out of shape.

So much for plans so we opted for plan two and another point just a bit farther away. Luckily we have a pretty dense network of control monuments.

I set up the base while Michael, fending off mosqito's started up the base and rover.

A nice place to also have lunch with a babbling (actually roaring today) brook that was nearby. We've had 7 or so inches of rain in a very short period so most things low are flooded and everything that can turn green is flourishing. The downside of the wetlands and warm temps are that we are having what seems to be a bumper crop of mosqito's.

I will not say that ours are bigger than others but I have heard many of them are required to file flight plans with the FAA. :)

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Found three out of four corners without any trouble and had lot's of evidence that verifide that they were the same points used over the years.

CCR's, ODOT Form 11's, highway plans, City Engineers notes, deeds and such. Standard research fare for a survey.

We can switch from static to RTK without any trouble so we like to shoot in the references with RTK where possible as a check on our swing ties. Here Michael is shooting in a ODOT cap on a headwall that has no markings to add as an extra reference. Our CCR's will have the three required (usually more) plus often ties to the four nearby other PLSS corners with grid bearings, grid distance and ground distance.

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I said three of four went smooth. Actually the fourth was smooth but it did have a perplexing complication.

I had seen this point about 10 years ago but at the time it was not needed in the project so we did not shoot it then. It was a simple pk (Parker-Kaylon) nail with shiner in the east bound lanes of Lee Boulevard.

So today we pulled some rough ties and spent a bit of time running back and forth as this was a divided four lane and posted 75mph. That is why we painted the circle. Not graffiti but when you have a short time in traffic then you want to be able to find the point very quickly.

Side Note-The traffic counts and traffic GIS layer are pretty handy at finding the slow times for these sorts of points.

Well, lordy, lordy, what do we find but two points on this go around.

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ODOT does a wonderful job on their Form 11's. They usually, in our area, set three references on a straight line away from their corners and their distances are meticulous measured.

We found these and taped along the line of pins and hit spot on to the PK nail called in their plans, on their Form 11 and in several deeds of the area.

The mag nail had no pedigree that we could find and there had been no updated CCR (Certified Corner Record) filed on this point.

I really have no explanation how someone could come this close to an existing point and fail to find it or fail to honor it based on the legacy of data to the PK nail.

It really seems silly when you consider that we have no evidence of when the original stone was destroyed and we have gaps in the research.

The PK dates to around 1960. Not all that old but it was set over a 1/2" iron pin when they rebuilt the road. The pin was destroyed and this surface marker set in it's position.

Things that just make you go . Hmmm.

Deral



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