Thanks, Mark. I will check that out.

No, they are wider than 3 feet, maybe 6 feet, although the open ends are 8 feet by 8 feet.

Jim...that is a 4 m rod folded in half so that we could get it on the points (inverted).Today's tunnel was smaller (I believe it is 8 foot high by 3 f...

I guess Radar's picture is of the station itself, mine was of the azimuth mark. Probably some feminist beat on the station mark so that it was unreada...

we want them rounded so that we can level to them easier. We were in a different tunnel from the one pictured today, and these huge channel catfish k...

there is no force on these other than gravity, and they are small carriage bolts with a rounded head. We are going to reset the loose ones, using a wi...

I have actually been to that point, right next to an FAA radar/communications station.www.terrasurv.com/images/poontang.jpgI was up there when we were...

It MIGHT be that certain servers at NGS behave differently. Not all data is processed on a single server, maybe they have slightly different versions ...

That has been an issue, I though they would not process at all if they were present. Not sure why they can't just ignore them. I always strip out the ...

I submitted two 24 hour files for that station to Trimble Centerpoint, one before the change and one after the change. Both had sigmas of 2/5/6 mm (N/...

I missed the original post that it was a 360?ø prism. There can definitely be some error introduced by not having a prism pointed directly back at the...

D+R will take care of vertical discrepancies due to cross hairs, vertical circle, etc. But not refraction. Reciprocal observations (near-simultaneous)...

That is a possibility, Gene. The log has been updated, but maybe they have not updated their processing script. I did look at photos, but I don't know...

Is it autolock (i.e. robotic)?If not, the vertical error depends on where you point and how accurate the HI is. It may be that at a longer distance yo...

This must be the worst performing CORS on the stable part of North America...look at the estimated accuracies...1 National Geodetic Survey, R...

Yea, that is a good question as well.

Here is another one...On August 2, 2017 they changed the receiver from a LEICA GRX1200GGPRO to a LEICA GR25, and the antenna from LEIAX1202GG to LEIAR...

I believe it is SOPAC that publishes daily positions for all of the stations in their database. I think NGS should give us the same, rather than just ...