+pgrig Posted January 11, 2008 Share Posted January 11, 2008 I'm new at this (and this is my first post), so I need help. I am working with an older quad map near Boston (LEXINGTON, 1971). I thought I'd find the "BM" symbols shown on the map in the USGS benchmark database. But after taking the UTM coodinates of a nearby one of these from the map (pretty sure I did that right, since some other benchmarks within 1 mi. of my target were returned to me by the USGS BM locator database), the "BM" indicated on the map was not among those returned. Are the "BM"s shown on my quad map somehow different from those in the USGS database? The mapped "BM" I was trying to find in the database was what I think you call a vertical control point (105 ft.) shown on my map at approx. UTM coordinates: 0324054 4700190. Thanks, PGrig Quote Link to comment
+GEO*Trailblazer 1 Posted January 11, 2008 Share Posted January 11, 2008 USGS BENCHMARKS DISCUSSION You may find some of your answers here it is quite long but we hashed through some of the reasons. You need to get the physical go to for most of them. But some of us get lucky and find a few now and then. Read through and ask again if you have more questions. Quote Link to comment
+Black Dog Trackers Posted January 11, 2008 Share Posted January 11, 2008 pgrig - It is not at all rare to find USGS marks that are not in the database we use, which is not a USGS database. This is explained a bit more here in the Benchmark Hunting FAQ. Quote Link to comment
+Holtie22 Posted January 11, 2008 Share Posted January 11, 2008 pgrig Is this the area where you found the mark? It is from the current version of the USGS quad at TopoZone. (The elevations on the map are metric.) If so, and you would like more info about the mark, you will need to contact the USGS directly for a copy of the vertical and/or horizontal control data for that area. The link in geo's post will tell you how to do that. If you want to log your find, you can do so at Waymarking.com You can access the NGS database overlaid on a variety of map backgrounds by using monkeykat's Benchmark Viewer. Quote Link to comment
+pgrig Posted January 11, 2008 Author Share Posted January 11, 2008 Thanks to all three of you, and boy, was that fast! I now get it that NGS is different from USGS, and am beginning to understand USGS BMs as a subset of the copy of the NGS database that we use. I will go through Dale's very helpful Q&A a couple of more times. Then (gasp!), I will go out and look for the USGS benchmark I saw on my paper map and see what's up. I may also try asking USGS for more info on its BMs near me. I will say that the variety of mapping and BM cross-referencing aids available ( and that you guys have linked to for me) seems vast to the newcomer (MEGO--my eyes glaze over!). More homework needed! Thanks again, -PGrig PS Holtie22: Yes this is the general area, but "my" USGS BM does not show on the map you linked to. I believe "mine" is about 500m south of the 27.5m BM indicated in the NE part of the area you linked to. Quote Link to comment
Wintertime Posted January 11, 2008 Share Posted January 11, 2008 I now get it that NGS is different from USGS, and am beginning to understand USGS BMs as a subset of the copy of the NGS database that we use. More like a different set. Although some USGS marks are in the NGS database, and thus form a subset of that DB, many other USGS marks have not been filed with the NGS. So they're two overlapping sets. (Insert Venn diagram here. ) Patty Quote Link to comment
+frex3wv Posted January 11, 2008 Share Posted January 11, 2008 pgrig - welcome to the hunt - it looks like you will catch on fast and you have come into this part of the GPS hobby (or whatever) at a great time as the USGS part was just pretty recently hashed out on here (as mentioned above). The folks on here (me excluded at this stage) are an awesome resource and are super smart and experienced and VERY nice (i'll include myslef on the last one! ha) - so don't hesitate to ask more questions - you will see that I have asked many! By the way - in some ways - for me - the USGS ones are alot funner to find because very few know of, and are looking for them Good luck - enjoy, and again - welcome! Quote Link to comment
+Black Dog Trackers Posted January 11, 2008 Share Posted January 11, 2008 By the way, the number of USGS monumented marks that happen to be included in the NGS database is 41,483. (I looked for "MONUMENTED USGS" in the datasheets.) I guess there could be 2 or 3 times that many USGS marks that are not included in the NGS database. The breakdown by monumentation date is: 1835 1 1871 2 1876 1 1877 1 1878 1 1879 1 1880 1 1881 2 1882 1 1884 2 1885 1 1886 1 1889 3 1891 1 1892 2 1893 1 1894 3 1895 1 1896 30 1897 19 1898 45 1899 137 1900 105 1901 75 1902 156 1903 560 1904 134 1905 207 1906 134 1907 185 1908 246 1909 128 1910 108 1911 137 1912 135 1913 117 1914 70 1915 213 1916 166 1917 204 1918 190 1919 174 1920 213 1921 145 1922 185 1923 306 1924 244 1925 338 1926 317 1927 248 1928 496 1929 438 1930 409 1931 568 1932 368 1933 658 1934 1278 1935 420 1936 219 1937 151 1938 371 1939 238 1940 246 1941 403 1942 322 1943 180 1944 164 1945 229 1946 520 1947 915 1948 1292 1949 755 1950 883 1951 688 1952 748 1953 601 1954 538 1955 595 1956 577 1957 531 1958 605 1959 672 1960 369 1961 296 1962 596 1963 672 1964 616 1965 510 1966 801 1967 914 1968 814 1969 510 1970 867 1971 593 1972 639 1973 595 1974 293 1975 156 1976 229 1977 91 1978 113 1979 166 1980 33 1981 25 1982 19 1983 190 1984 112 1985 30 1986 34 1987 10 1988 14 1989 3 1991 2 1992 3 1993 9 1994 1 1996 2 1999 4 2000 2 2001 2 2003 3 2004 11 2005 8 UNK 8351 Quote Link to comment
+pgrig Posted January 11, 2008 Author Share Posted January 11, 2008 By the way, the number of USGS monumented marks that happen to be included in the NGS database is 41,483. (I looked for "MONUMENTED USGS" in the datasheets.) I guess there could be 2 or 3 times that many USGS marks that are not included in the NGS database. The breakdown by monumentation date is: 1835 1 1871 2 1876 1 1877 1 1878 1 1879 1 1880 1 1881 2 1882 1 1884 2 1885 1 1886 1 1889 3 1891 1 1892 2 1893 1 1894 3 1895 1 1896 30 1897 19 1898 45 1899 137 1900 105 1901 75 1902 156 1903 560 1904 134 1905 207 1906 134 1907 185 1908 246 1909 128 1910 108 1911 137 1912 135 1913 117 1914 70 1915 213 1916 166 1917 204 1918 190 1919 174 1920 213 1921 145 1922 185 1923 306 1924 244 1925 338 1926 317 1927 248 1928 496 1929 438 1930 409 1931 568 1932 368 1933 658 1934 1278 1935 420 1936 219 1937 151 1938 371 1939 238 1940 246 1941 403 1942 322 1943 180 1944 164 1945 229 1946 520 1947 915 1948 1292 1949 755 1950 883 1951 688 1952 748 1953 601 1954 538 1955 595 1956 577 1957 531 1958 605 1959 672 1960 369 1961 296 1962 596 1963 672 1964 616 1965 510 1966 801 1967 914 1968 814 1969 510 1970 867 1971 593 1972 639 1973 595 1974 293 1975 156 1976 229 1977 91 1978 113 1979 166 1980 33 1981 25 1982 19 1983 190 1984 112 1985 30 1986 34 1987 10 1988 14 1989 3 1991 2 1992 3 1993 9 1994 1 1996 2 1999 4 2000 2 2001 2 2003 3 2004 11 2005 8 UNK 8351 So basically what you're telling me is that level of USGS monumentation activity is inversely related to the health of the American economy (with a couple of "outlier" years)...very interesting. Looks like we're heading into another period of "monumental growth" right now, huh? Quote Link to comment
Z15 Posted January 11, 2008 Share Posted January 11, 2008 (edited) Most of the USGS marks are in the NGS database because in the course of NGS's field surveys they found and used the marks. Yes there are those that USGS submitted for inclusion but the number is small in comparison to what NGS found and used or as they say in the profession, Tied in. read this post .. 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. Edited January 11, 2008 by Z15 Quote Link to comment
square nail Posted January 12, 2008 Share Posted January 12, 2008 pgrig, I like to pick the x's off of quad maps just for the challenge to see if I can find them. Most of the time they are within 50 feet of the coordinates. I have attached a link that I think you would enjoy and likley learn a bunch. http://www.cachingnow.com/BenchmarkHunting...07/Default.aspx Keep looking. square nail Quote Link to comment
+Holtie22 Posted January 12, 2008 Share Posted January 12, 2008 Yet another source of info for older USGS marks are the historic maps found in various collections. It looks like "your" BM is on Winthrop Street near the town line between Winchester and Medford. Quote Link to comment
DaveD Posted January 13, 2008 Share Posted January 13, 2008 Black Dog - Do you have the PIDs for the 1835 - 1878 USGS marks. The organization was created until 1879 so those have to be typos and I'll try to have them corrected. Quote Link to comment
+pgrig Posted January 13, 2008 Author Share Posted January 13, 2008 Holtie22-- Your helpful response started me looking for even older quad maps. I found this one in a collection that Harvard apparently maintains. It says it was surveyed in 1898 (!), and is a little hard to read, but apparently doesn't show any BM symbols at all. When did BMs start being shown by USGS? Quote Link to comment
+Black Dog Trackers Posted January 13, 2008 Share Posted January 13, 2008 DavdD - Certainly, here they are: ON0039 1835 GQ0288 1871 GQ0323 1871 JT2787 1876 MS0615 1877 PF0922 1878 I also have found lists of such things as NGS monumentations in the 1800s PD0792 and recoveries by NGS in the HISTORY section in the early 1900s (DH1409), etc. if you want those too. I was doing some interesting graphs when I found these. Quote Link to comment
Papa-Bear-NYC Posted January 13, 2008 Share Posted January 13, 2008 (edited) Holtie22-- Your helpful response started me looking for even older quad maps. I found this one in a collection that Harvard apparently maintains. It says it was surveyed in 1898 (!), and is a little hard to read, but apparently doesn't show any BM symbols at all. When did BMs start being shown by USGS? Here's an easier to read version of that map from the University of New Hampshire collection. It's the same 1903 version but reprinted in 1942: http://docs.unh.edu/nhtopos/Boston.htm It's digitized in 4 overlapping pieces. The northwest piece is an earlier version of Holtie's map. One difference is that the 2 Mystic Lakes were just one lake then. It's true I don't see any BMs on that map, but I've seen plenty on maps of that vintage (like the one of the Orono Maine quad which shows a circa 1900 BM I found (PE0518) on the U of Maine Campus: Orono Map Edited January 13, 2008 by Papa-Bear-NYC Quote Link to comment
ArtMan Posted January 14, 2008 Share Posted January 14, 2008 Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine). Quote Link to comment
Papa-Bear-NYC Posted January 14, 2008 Share Posted January 14, 2008 Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine). Hi ArtMAnI keep getting "Currently Not Available" when I drill down for for any of the MapTech maps. Am I doing something wrong? Quote Link to comment
ArtMan Posted January 14, 2008 Share Posted January 14, 2008 Another source of historical topo maps is Maptech, which has nice quality scans from 14 northeastern states (Ohio, West Virginia, and Virginia, up through Maine). Hi ArtMAnI keep getting "Currently Not Available" when I drill down for for any of the MapTech maps. Am I doing something wrong? I'm seeing the same problem still on Monday morning. I just sent a note to the person listed as their tech contact in whois (the website didn't seem to have a useful email contact listed) and we'll see what happens. -ArtMan- Quote Link to comment
ArtMan Posted January 14, 2008 Share Posted January 14, 2008 Maptech historical maps are back online now. -ArtMan- Quote Link to comment
Astrak_1001 Posted January 15, 2008 Share Posted January 15, 2008 Some USGS monuments(mind you they are monuments not benchmarks, benchmarks are used for vertical and may or may not have an exact horizontal location associated with them) that were surveyed in the early days have a magnetic north location, not a true north or grid north horizontal location and have not been tied down to a GPS grid even though they have a lat and long in the USGS database...these were just a guess based on surveys of other monuments that were tied down. Even then some may be off due to the fact they were tied down before the advent of RTK surveying and are static locations. Quote Link to comment
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