The speed of light in the atmosphere depends on the density of the air, which is affected by temperature, pressure, and, to a lesser extent, humidity....

I just spent a few days in the North Woods of Maine, fascinating area. I drove through there extensively, and never saw a single power line, gas line,...

Jim: the problem I had was many years ago, early 90's. i would hope they came up with a better design. I noticed it first when we ran up a 400' high h...

Yes, that is the same device in the picture. I could not get close to the white panel to see exactly what it said, but I could see that there were dat...

We use a Dini 12. It works great most of the time, but does have issues with sunlight/shadows as many other levels do as well. Since it is basically t...

I do not understand the desire for anonymity. I would not want to work for someone who made me fell I cannot speak my mind.

I shipped equipment by fedex on my first overseas trip-bad idea. It was to USVI, and it got held up in customs (US). Finally got it released because w...

NAD83(2011)-CLARIFICATIONA clarification is in order. I misspoke. What I meant to say was that the shifts from NAD27 to NAD83(86) had a range of 1+ me...

You are right, they are fine for most mapping. Just not for surveying. Although, since NADCON is "approved" (in the Federal register) as the official ...

I should add that I am more accustomed to seeing an accuracy of 0.15 m in the NADCON transformation here in the east (western PA). I started doing GPS...

As Dave said, the transformations in NADCON are the best available, but not good enough for survey. If I want good NAD27, I tie in NAD27 stations and ...

then you will have a WGS84 position ± a few meters. Since the transformation is 0,0,0 that is what you will have. Not worth the trouble to transform n...

NAD83(CONUS) Molodensky has transformation parameters of 0,0,0. You do not need any other file as long as you put a NAD83(2011) coordinate in for your...

Add A Tie Check At MinimumWell, I don't actually enter azimuths, I enter angles (or directions). What I mean is that anytime I need to deal with an az...

Add A Tie Check At MinimumI do my comps using azimuths and grads. No dms, no quadrants. Makes the math easier.

Before the days of CORS/HARN stations, we would have to recover old triangulation monuments for control. If the surface mark was missing, but the desc...

I am not a Topcon user but I would guess that "NAD83" is applying transformation parameters to a supposedly WGS84 (ITRF) position. However, if the ori...

well, that (0.13) would really only apply if you were shooting hilltop to hilltop, with plenty of ground clearance in between. For critical shots I do...