Dr. Dennis has noted the lack of publicly-available documentation for state plane development and the process he's overseeing aims at improving that s...

So you're saying that NGS got the eccentricity squared wrong? I can see how that could happen given the complexity of Moritz's iterative solution. I'l...

John, I have an old pencil note that I made at some time in the past that shows those digits to be ...2711243. I have no idea how I came up with that,...

So, pdf page 36 of this publication ?ÿsays that the SAF for Bexar County is 1.00017, which squares with the AY1896 and DG5157 combined factors. It's ...

Always a fascinating topic. Look at 3 points (I know, not an adequate sample) near San Antonio: AY1896, AY1924, and DG5157. For each of these points, ...

Yeah, it's April, not March. There are two papers, one for Policies and another for Procedures, both dated April. You really have to read them both, b...

Every time I read the March 23 documents, I end up confused, but I think that the 62 separate ones would not be designed by NGS. Their design would be...

The NAD 83 state plane for Long Island looks like a pretty good LDP itself. Distortion at the central parallel is only -5.1 parts per million, with ma...

Here are the solutions to problem 4. This modified .prj puts the grid origin at KJ0524 and uses a different false Easting and false Northing to make c...

Thanks for the comments, John. The easy one to address is the degree-radian factor, which, according to the calculator in my Pixel 2, is truncated at ...

The answers to Problem 3 are: Limon CBL LDP Coordinates in meters: KJ0231: 26,639.255N, 90,083.433EKJ0524: 17,242.721N, 97,242.883E Grid distance = 11...

The solutions to Problem 2 are: Runway 16 coordinates (meters): 26,413.260N, 99,715.680ERunway 34 coordinates (meters):25,004.277N, 99,974.346EGrid di...

This one started as an Iowa Regional Coordinate System .prj, which is an Esri file that uses the word "spheroid." I don't remember which one I used, b...

Thanks, John. My old rheumy eyes are getting older and rheumier. We see one of the objections to LDPs in problem 4, where we create a second, overlap...

As long as odometers are in miles, the highway people will need feet ????.