A Google search on "yolo base line" will bring up lots of links to photos and some text information.?ÿ There's even a Facebook group, though it's not very active.
The 1882 USC&GS annual report to the Superintendent contains a lot of descriptive material about the Yolo Base Line.?ÿ I've attached the relevant appendix.
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@jim-frame?ÿ ?ÿSo Jim did you ever GPS the Yolo base line? NGS Appendix #8 for 1882 does not give that much information.
I would like to know all about the final distance, the reduction to sea level, etc. The only way you can get this information is through NGS; by a " station report ". It seems that no one at NGS knows how to do this. In the old days Ed Mckay did this for me for the Michelson base line in Southern CA. The Yolo base line distance that Chuck Fronczek reports in a paper he wrote?ÿ
is 17486.595 meters (Mech.?ÿ Apparatus Distance) and a Geodimeter distance measurement of 17486.574 meters?ÿ (year and type of geodimeter was not listed). Thats 21mm difference or 1/833000 (please note that C.F. rounded up to 1/833000). I was always taught to round down to the nearest 100 meters.
JOHN NOLTON
That's one of those projects that just hadn't made it to the top of the to-do list, I'm afraid.?ÿ I did get as far as building a custom short tripod that will sit securely on top of the granite obelisk. (I already had another short tripod that will work on the other obelisk.)
One of these days...
@jim-frame?ÿ Jim several questions.?ÿ
1. What type of GPS equipment do you have.
2. If you can fine the other end of the base line, HOW long would you observe it with your Units?
JOHN NOLTON
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1.?ÿ I'd be using Trimble 4000SSi receivers and Trimble Zephyr Geodetic antennas.
2.?ÿ ?ÿThe other end has already been found.?ÿ I'd observe for at least 2 hours so I could get the data into OPUS Projects, but I'd also process in Trimble Business Center just to get a closer look at the data.
How come I'm not seeing any of the photos?
They may have been loaded in my webspace when disk was at a premium, causing me to unload them after a few months.?ÿ When I'm back in the office at the end of next week I'll take a look.
OK, thanks. I lived for years in Rumsey, CA and still explore the region on travels. I also have students in that region with whom I connect. I would love to know more about the Yolo base line and how to find the markers.