UTM Question

Why in blue thunder would UTM coordinates be used at all? Not illegal, but highly irregular.?ÿ I'm going to guess that whoever did that wasn't real well versed in the world of grid projections. You should be doing the happy dance about being within 10 feet.

Anytime I see GPS derived coordinates out to 4 decimal places, it starts the alarm bells ringing. I've got some coordinates on other points that this record ties to and not sure how useful these UTM coordinates are going to be. Hopefully their reference ties are useable.

It the rare OCCR that has coordinates on it of any kind. And reference dimensions, particularly on the older ones, are often rag taped and compassed.?ÿ The thinking being to use the references to help you find the corner, but not to restore it from references ties.

I have a few clients who use UTM exclusively. The system is great for tracking resources globally. I'm not sure why it would appear on a corner record, or why the record would not include metadata.

As for the 4 decimal places, that's probably a lack of experience or care. Hopefully the former..?ÿ

UTM zones are large so there is distortion to deal with. That being said many companies use it and want the surveyor to also use it. Meshing in with their data is the only reason I've ever found myself using UTM. I have one company that wants all data UTM meters sent to their GIS department, but all the plans and drawings have to be in USft.?ÿThey don't want?ÿto build a?ÿfacility in meters. That would be a nightmare.

I supply UTM (and SPC if needed, some do not need or use SPC) on all control jobs. The Pittsburgh district of the USACE for example covers 7 SPC zones, but a single UTM zone. So I setup a database for them with all of the navigation projects deformation surveys (23 separate dams) and everything is in UTM meters. But, they have at times requested UTM feet for GIS purposes. A lot of photo control work I do is for military bases, they usually (but not always) want UTM meters.

?ÿ

I can be anywhere in the world and know just from the coordinates which zone I am in. All of the zones are the same (repeating every 6?ø) And it is directly convertible to a USNG coordinate.?ÿ

I think the problem in the past with using UTM was that the SF is usually MUCH larger than SPC, but with modern data collectors and computers that should not even be much of an issue.?ÿ

I saw a deed in Mexico for a large forest tract that was all in UTM (and only UTM). All distances were UTM grid, all bearings were UTM. And it referenced the datum used as well.?ÿ

I have been "dealing" with UTM Coordinates (NAD27 & NAD83) for decades. I don't see any problems in the PROPER use of UTM, or State Plane for that matter. Unfortunately, it appears that a large percentage of surveyors, and a huge majority of "other users," don't have a fricking clue HOW to "properly" use?ÿUTM coordinates (or State Plane?ÿcoordinates for that matter).

I see?ÿUTM coordinates in FEET from time to time, and it's just one of those things that we all have to deal with when evaluating data supplied by clients.

?ÿIt all comes back to metadata, or more precisely the?ÿABSENCE thereof. I see a LOT of UTM data (NAD27 & NAD83) that was derived from "Garmin" handheld receivers. There is NO/zero mention of this in the data, but it doesn't take too long to see the handwriting on the outhouse wall.

Fun and games,

Loyal

I've had UTM requested by an engineering firm I do some work for.

I do everything in TBC and keep on proper Lat/Long.?ÿ Conversion is easy with the software, just need to keep all the units and such correct.?ÿ Switching projections no problem.?ÿ UTM is just another projection.?ÿ If your lat/long is correct converts easily.

BLM in the Gulf of Mexico uses UTM in US survey feet. The EPSG registry ended up adding more USft-based zones to cover the rest of the US a few years ago.

Down this way, the local grid for title and property survey work is TM WGS72 based with false N,E CM scale factor, zone width 6, etc. We use it for our surveys for engineering purposes. Last week we were doing a topo of two sites on one of the outer islands. At the first site, fired up the RTK-GNSS gear, set SurvCE job to local grid. Coordinates, big negative numbers - WTF. Restarted everything, same result, sweat running southwards, vultures circling. I'd done a survey on this same island 3 years ago, maybe 20km south west of where we were this day, and the local grid worked, so again WTF. Fired up the Garmin and realised we were on the other side of the 0-180, but couldn't begin to think about how that had "fouled" up the local grid, so switched the job to UTM WGS84 and did the surveys.

UTM are in fairly common usage in large aerial mapping projects that cover multiple SPC zones, we currently are working on mapping for the?ÿStewardship Lands Imagery (SLI) program and UTM is the delivery coordinate system. Just another grid system, we have SPC, a GIS geared Oregon Single Zone Lambert and about 40 Oregon Coordinate Reference System or OCRS (LDP's) plus the continued use of scaled SPC and probably some I am missing all in common use in Oregon. MetaData is the key to knowing what you have and are passing on to the next person in the loop.

SHG

here in Northern Baja all property deeds I run into are tied to a local UTM monument, in meters.
I assume it is the same for all of Mexico.

My surveyor of choice records and publishes Lan/Lon as well as UTM on his plats, with adequate metadata.