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USGS Benchmarks


Nakedbamboo

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I found a benchmark in Colorado that was not located in the Groundspeak database, so I went and searched the NOAA database and it was not there either. I emailed support and asked them what it could be and received the response that it might be owned by the USGS or a state agency. Benchmarks only show up in the NOAA database if they have ever "leveled" to them.

 

I went to the USGS website and cannot seem to find anything like a benchmark database there. Would anyone know how to find a database on USGS benchmarks or Colorado owned benchmarks?

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Counties often have their own databases as well. Sometimes they include NGS (NOAA) benchmarks, but there seem to be many more in the several I have looked at that are county only. I don't remember the county ones having any USGS, but I guess it is possible.

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Nakedbamboo -

 

The question is, which agency placed the mark you found? Generally, the way to determine that is to read the disk and it will tell you. It might be a USGS mark, or it might be a state of Colorado mark, or it might be some county mark, or it might be a department of interior mark, etc. Check BuckBrooke's benchmark agencies site for examples of reading the agency from the disk.

 

There are some states and counties that have put their benchmark location data online. Check out Zhanna's local control database collection for examples.

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FYI

 

The U.S. Geological Survey (USGS), an agency in the Dept. of the Interior has the responsibility for producing our national topographic maps. They completed the monumental task of complete national mapping of the 1:24,000 scale map series (about 55,000 maps) in the early 1990's. USGS would often set survey monuments to help "control" the map. Maps are produced from aeronautical photos mosaiced together. In order to provide accurate location, orientation, scale and elevation to a flat map of a curved surface, it is required to have numerous points that can be identified on the photographs for which the coordinates/elevations are well known. The marks set by USGS were a vital part of this operation. In the days when mapping surveys were conducted primarily by line-of-site methods, these marks helped save money by helping to ensure a network that cartographers could rely on for mapping update procedures. With the rapid developments in surveying and mapping technology, especially GPS, USGS sees little need to setting new marks or maintaining the old networks. Unfortunately the data for tens of thousands of these marks set by USGS were never submitted to NGS for inclusion in the National Spatial Reference System. Due to major reductions in staff and the changing nature of mapping requirements, it is highly unlikely that USGS will ever automate these data.
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FYI

 

The U.S. Geological Survey (USGS), an agency in the Dept. of the Interior has the responsibility for producing our national topographic maps. They completed the monumental task of complete national mapping of the 1:24,000 scale map series (about 55,000 maps) in the early 1990's. USGS would often set survey monuments to help "control" the map. Maps are produced from aeronautical photos mosaiced together. In order to provide accurate location, orientation, scale and elevation to a flat map of a curved surface, it is required to have numerous points that can be identified on the photographs for which the coordinates/elevations are well known. The marks set by USGS were a vital part of this operation. In the days when mapping surveys were conducted primarily by line-of-site methods, these marks helped save money by helping to ensure a network that cartographers could rely on for mapping update procedures. With the rapid developments in surveying and mapping technology, especially GPS, USGS sees little need to setting new marks or maintaining the old networks. Unfortunately the data for tens of thousands of these marks set by USGS were never submitted to NGS for inclusion in the National Spatial Reference System. Due to major reductions in staff and the changing nature of mapping requirements, it is highly unlikely that USGS will ever automate these data.

 

Sigh...they are my favorites. Just found one up in Racine County, WI but have not gotten a chance to log it on Waymarking.com yet

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