RHJensen Posted October 30, 2002 Share Posted October 30, 2002 I'm using OziExplorer with some 1:24K DRGs of my area and notice that there are notations: "BM 30" by a small X on the map. On the USGS site I found that this means a Third Order or better vertical control (i.e., benchmark) with tablet. Some of these are, in fact, close to the coordinates of area benchmarks I've downloaded with EasyGPS. If I didn't get something close with EasyGPS is it likely that the mark has been 'Destroyed' or 'Not Found'? I'd also like some feedback about HT2744. I see EIGHT monumented entries! And it seems to keep washing away! Should I even try to recover this mark? How do other people use the descriptions to guide going after a benchmark? Richard. Quote Link to comment
+Udink Posted October 31, 2002 Share Posted October 31, 2002 As to your first question, if I understand it correctly, the answer is, "Not necessarily." I've physically found benchmarks that don't exist in the NGS database, but exist on a topo map. I've also found benchmarks that exist in the NGS database, but aren't included on a topo map. The former case is the worst, as there's no way to log the benchmark on this site. The only real way to be sure is to look at the physical location for the benchmark (I know, I'm not much help). =) Quote Link to comment
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