BMs listed on USGS maps

[MOCKBA]

I came across U.S. Geological Survey map designations for controls and monuments (http://mac.usgs.gov/isb/pubs/booklets/symbols/elevation.html) and apparently the quad maps show quite a bit of detailed info on the benchmarks. Wouldn't you think that they at USGS should have some database with these data? I.e. perhaps not for *all* USGS BMs, but at least for the ones explicitly used on the quads? Anybody knows?

Now if I'm wrong and the USGS quad BM data are scattered all over their files, rather than centralized or consolidated in any meaningful way, then perhaps gc.com should provide an option of enetering them in the local database. We can use coordinates from the quads or empirically observed GPS coords for these. Again, the BM must be on a map before one can add it to the local db. And if, in the future, the USGS data are made available through the NGS database, then both records should be fused upon next importation of NGS data in gc.com database.

[Z15]

Yes, they have a database of sorts. But its in paper form. Nothing on line, if you inquire about a point, they have to manually dig thru records to find it.

 

The BM's you find noted on the USGS maps are there beause their field partys located them in the field at the time of the field check. They no longer have the money or the people to carry on mapping to the extent it was done it the past. Everything you find on the maps was noted there when in the field or from aerial photographs.

 

 

Here is an example of USGS control info.

 

 

Mike

Survey Tech (Retired)

[DaveD]

If you look in the bottom left hand corner of each USGS 7.5 minute topographic map it will tell you whos' control was used by USGS to produce the map. Typically you will find USGS, USC&GS and sometimes USACE (Army Corps of Engineers). The USGS "data base" is as noted, nothing more than file cabinets full of paper data. USGS has NO intention of ever automating or digitizing these data. Especially with the developments in GPS technology this is a non-issue to them any more. The only USGS marks not already in the NGS data base that will ever get into the NGS data base are those that are repositioned by some future GPS survey -- which means not very many

[MOCKBA]

quote:

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Originally posted by DaveD:

The USGS "data base" is as noted, nothing more than file cabinets full of paper data. USGS has NO intention of ever automating or digitizing these data. Especially with the developments in GPS technology this is a non-issue to them any more

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Makes sense. The value of these markers is mostly historical ... and that's exactly what makes a lot of us excited.

Which returns us to my earlier point. It would make perfect sense to enter these prominent BMs into GC.com database, irrespectively of their absense from the NGS list. Fun locations and survey history -> exactly what our hobby is about.

[Z15]

I can't find it at the moment but the title page 1 from the quad I listed above says something to the effect.

 

quote:

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OBSOLETE CONTROL

DUE TO THE METHODS EMPLOYED AND THE IMPROBABILITY OF RECOVERY, NO FURTHER TIES ARE WARRANTED.

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Some time (yrs) ago I was watching an old episode of "Mission Impossible". One of the IM team cover was that he was an USGS Engineer there to do the Polyconic projection for local maps.

 

Mike

Survey Tech (Retired)