I'm looking at a couple of NGS horizontal monuments in Reeves County and notice some of them include "ET" in their name. In particular a few around Orla are "RED ET" and "CHAPMAN ET". Both were set in 1969 as well as the station "ORLA". I can't find RED ET or CHAPMAN ET on the NGS GIS Map but ORLA is there. Anybody know what the ET stands for other than the obvious extra-terrestrial joke?
Howdy,
As you know, the NGS Data Base includes monuments established by other agencies. I expect this was set by the USGS. The designation indicates "Electronic Traverse." Other designations include "TT" for "Transit Traverse."
Perhaps someone from USGS might have additional information. I recollect some large discrepancies between sequential monuments on a project in Wyoming. This led to my first experience with GPS where we tied th USGS point to the NGS triangulation network.
Cheers,
DMM
Yeah, I googled a little before I posted the question and probably didn't word my inquiry good enough to get that answer but I see it now. Thanks.
I'm not sure how the crew found the marker unless they stumbled across it since it's not on the GIS Map. I'd rather they tied into existing control but I think they collected plenty of data to run it through OPUS.
You must be correct. I have stumbled across USGS TT markers here and learned that the "TT" was for transit traverse
I just pulled both datasheets and they are both USGS and both ET. In fact, the tablet is stamped ET but for some reason in the online database the ET is missing, unless you look at the station mark description.
That's what was confusing me.
As Mike said ET = Electronic Traverse. This was used by USGS. In addition to TT they also used PTS = Primary Traverse Station. Some (just a few) USGS horizontal projects were submitted by them to NGS for inclusion in the original NAD 83 adjustment, most of them in the western U.S. In addition, sometimes USC&GS/NGS would tie these stations in during their routine triangulation projects if they were located at convenient sites.
Be careful at Chapman ET, there is a USGS BM about 5' away, Chapman is "outside" the Hwy ROW fnc, the BM is inside the fnc. Excellent station to occupy.
Red ET is also just outside the fence, best access is from an abd well just west of Red.
The crews are no longer allowed to occupy stations in the vicinity of public roads due to repeated vandalism and theft of base stations. The monuments were originally tied when we set up our secondary control and anymore my preference is to use OPUS processed points when we add new control. Orla ET was an exception.