AE5D Posted October 7, 2003 Share Posted October 7, 2003 Today I found benchmark #128 (AB7758), which turned out to be a ''Topographic Station'', with a circle on the disk instead of a triangle or an arrow or some other symbol. This is the first mark of its kind that I have found. Is this a rare item? Quote Link to comment
DaveD Posted October 7, 2003 Share Posted October 7, 2003 Topographic disks were not very rare. They were typically set as part of either the early Coast & Geodetic Survey airport survey or nautical charting programs. These were generally set as lower order control points for very specific mapping control. Hundreds, maybe even thousands of these marks were set that were never surveyed to the standards of the national geodetic network. In this specific case the mark was set with a very low positional accuracy, but a very good local accuracy for the airport survey and later positioned with GPS and entered into the national reference frame Quote Link to comment
+synergicity Posted October 7, 2003 Share Posted October 7, 2003 I just have to say... DaveD - You rock! Thanks for contributing here. We appreciate it. Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.