+Black Dog Trackers Posted August 30, 2007 Share Posted August 30, 2007 In another topic, DaveD suggested I contact the USGS with some questions I had. I did so and here are my questions and the answers from the USGS. I wrote an email, got a response, wrote followup questions and got the answer to those; both series are here, separated by === lines. (My questions are in black, Dale's answers are in red bold.) The most important part is the answer to question 5, and the additional information pertaining to it at the end of this post. =========================================== I am embedding my replies in bold, red type within your email below. Dale Benson Hello, I am a participant in an effort to find bench marks and other survey marks and provide updating recovery reports on them. There are many of us who are associated with the Geocaching website (http://www.geocaching.com/mark/) and we log our finds there and also at the NGS website (http://www.ngs.noaa.gov/ngs-cgi-bin/recvy_entry_www.prl). (Since 2002, as a group, we have submitted over 25,000 mark recovery reports to the NGS.) Also, there is a website associated with the Geocaching website called the US Benchmarks category (http://www.Waymarking.com/cat/details.aspx?f=1&guid=424f2581-a02d-4914-9bc8-8f4cafe02680) for logging survey disks that are not included in the NGS database. Some of these are USGS disks, of course. Associated with the Geocaching site is a discussion forum on benchmark hunting (http://forums.Groundspeak.com/GC/index.php?showforum=10). I should make it clear that, although a few of our group are professional surveyors, in general we are simply hobbyists that enjoy finding survey marks and reporting our finds on the Geocaching and NGS websites, usually with photographs. Quite often in the benchmark hunting forum mentioned above, questions come up about USGS bench mark disks. I'm hoping that you could answer a few of these questions via email: 1. How many survey disks (bench mark, triangulation, etc. but not counting reference marks and azimuth marks) were set by the USGS? There is no precise record on the number of USGS survey monuments set by our agency since its inception in 1879. Rough numbers would be in the tens of thousands. The vast majority of the marks were set in support of the various scales of topographic mapping of the nation over the years. Additionally, some marks were set by Mapping or other USGS Divisions in support of earthquake monitoring studies, crustal deformation studies, and water resources subsurface water and subsidence studies. The National Geospatial Technical Operation Center (NGTOC) offices in Denver, CO, and Rolla, MO, only have records on marks set by the former Topographic and National Mapping Divisions. Marks set by Geologic and Water Resources Divisions are maintained by those respective offices. 2. How many "BM" surveyed mark locations are indicated on U.S. topographic maps? Again, there is no absolute number of "BM" surveyed marks shown on our topographic maps. Marks shown with the label "BM" are those that have accurate elevations, but not necessarily surveyed horizontal positions. They were positioned on the maps through photoidentification on aerial photos during the field mapping phase, or, for maps older than roughly the mid-1960's, plotted on fieldboards with a planetable and alidade. USGS quadrangles show USGS marks, National Geodetic Survey (NGS) (formerly U.S. Coast and Geodetic Survey--USC&GS) marks, and some other official agency marks that were surveyed to third-order or better standards and approved by the USGS at the time of the mapping. Editorial policies during mapping operations specified showing benchmarks at no closer than one-half mile spacing. In most cases this was not a problem because monumented benchmarks and supplemental benchmarks (recoverable marks that were not tablets/disks) were set at approximately one mile spacing (one kilometer spacing in more recent years). The only time that the spacing requirement would come into play would be when both a USGS and NGS mark might be located in close proximity, or when marks were set close together in support of scientific studies. Then editorial thinning would take place. Horizontal stations are also shown on the topographic maps and indicated by triangles. These marks will have accurate horizontal positions, but most likely will not have accurately surveyed elevations. 3. How many of the USGS survey disks are included in the NGS database? Again, there is no definitive number. Many USGS horizontal stations are found in the NGS database, because either the NGS also occupied the marks, or the USGS surveyed observation records (angles and distances) were submitted to the NGS at the time the NAD83 national readjustment was undertaken in the early-to-mid 1980's. Very few USGS benchmarks are in the NGS database. Only those that NGS occupied, or those surveyed to second-order-or-better standards and submitted to NGS were placed in the database. There had been a plan for USGS to submit all their benchmark data to NGS for inclusion in the NAVD88 adjustment, but this never materialized because of resource limitations in both agencies. It is truly unfortunate that this did not occur. 4. Is there a way to request location information from USGS offices? Yes, for Montana, Wyoming, Colorado, New Mexico, Texas, and all states west of these you can contact the Geodetic Control number in Denver at 303-202-4400. For all remaining states contact the Earth Science Information Center in Rolla, MO, at 573-308-3500. If email would be the preferred method of correspondence, then it should be sent to firstname.lastname@example.org This address is not specific to any one office, and the requests may take longer to answer because they will have to be redirected to the correct location. USGS data is, as you stated, in paper format stored in file cabinets by 15-minute blocks corresponding to the old 15-minute map series. Ideally if requests can be made by USGS quad name or lat-lon positions it will be easy to track down the requested information. If the mark has been found, then the stamping on the mark will expedite the research even further. If only the elevation adjacent to the BM label on a Quad is available (along with the quad name), that is OK too. The desired information can be faxed or mailed back to the requestor. We can also provide the information by phone if a contact number is provided with the request. If BM information for a few quads is desired, we can handle that without difficulty. There is no charge for providing this information on a small scale. We don't encourage requests for large blocks of data, as filling these requests is a subordinate function for the few people handling the control information. There used to be a charge for providing the information, but it was so minimal that the time and effort to handle the charges were not worth the effort. I seem to recall someone saying in the forum that sending some particular amount of money to USGS office(s) would get copies of location information for all the USGS marks on a particular topographic quad. We have heard that the USGS survey mark location information is in paper form; not computerized. Oddly tnough, people usually ask in the forum for information about a particular USGS disk after they have already found that disk and noticed that it is not included in the NGS database. Perhaps they just want to know more about how its location was givenin paperwork. Is there some standard source(s) of copies of survey mark location information and its price? See above. 5. What is the USGS interest in receiving (via email, letter, etc.) 'find reports' (like the NGS recovery reports) on USGS disks? Yes, we would like to receive information on the condition of any USGS marks you find, as well as lat-lon coordinates and digital photo(s). I have received these in the past and placed them in the control folders. A few have been sent from geocachers, although most have been obtained from surveyors who wanted to provide an update on the status of marks they have used. The USGS descriptions are always old, and mostly out-of-date. In nearly all cases, the only recovery notes on record were submitted by USGS personnel during topographic field mapping operations, which hasn't occurred in decades. The method by which the recovery information can be forwarded to the USGS can be left open to the individual geocacher. We have received some information in emails, along with attached photos; letter with printed copies of the photos; or CDs mailed with spreadsheets and photos for marks on multiple quads. I suggest that any recovery information should be sent to the individual from whom the descriptive data was obtained. that way they can update our records. Again, it is unfortunate that the USGS does not have an on-line mechanism to report mark recoveries similar to NGS, but we do not. Thank you for your interest, Dale Benson Thank you very much for your patience, - Tom Kaye =========================================== I had some followup questions: =========================================== Dale - Thank you very much for your response to my email! I am certain that our folks will find your answers extremely interesting and even a bit surprising (the part about the USGS being interested in receiving mark condition reports). I do have a couple of followup questions. 1. You said that the USGS is interested in receiving information about USGS marks. Which of the following would be appropriate for this: a. Only those USGS marks that are not included in the NGS online database. b. All USGS marks. 1b. We would like to know about all USGS marks. 2. I believe that most of the time (maybe 80%) that people would be intending to send a condition report, they will not be needing to contact the USGS initially to be able to find the mark because they have *already* found it, either by searching at a "BM" mark on a topographic map, or by accident, or by seeing a witness indicator, or because the mark's position is given on the NGS database. They will just want to go ahead and send their report (and digital photos) via email to the USGS. Should they: a. Email their report to email@example.com b. Email their report to you (firstname.lastname@example.org) c. Call the 573-308-3500 number for Eastern-states or the Denver number for Western-states, being ready with the mark's designation, quad name, and state, or lat-lon data, and ask for an appropriate email address for sending the report d. Email to: email@example.com with the mark's designation, quad name, and state, or lat-lon data, and ask for an appropriate email address for sending the report e. Any of the above, whichever they feel like doing (I suggest, for sending mark condition reports, that it would be more efficient for us (and the USGS !) if we could skip the contact-asking phase (involving either calling the phone numbers or sending a question to firstname.lastname@example.org) and instead just go ahead and email to a standard Eastern-states email address, or a standard Western-states email address, as appropriate, but I don't know what those email addresses would be. Even if there are 50 email addresses for the 50 states, or maybe some regions, we could list that information in the forum and people could then refer to that list. We could use a standard email subject; something like "Mark recovery report".) Thank you ! - tom kaye 2. After consulting with the Information Services folks in both Denver and Rolla, the following decision was made: We prefer to receive recovery reports via email rather than phone. For Montana, Wyoming, Colorado, New Mexico, Texas, and all states west of these, use the WESTERN USA email account: email@example.com For all remaining states, use the EASTERN USA email account: firstname.lastname@example.org The pertinent information that should be provided includes: Stamping on mark: (e.g., 16 DOR 1976) 7.5-minute Quadrangle and State (if known) Latitude/Longitude position Condition of Mark: (e.g., Good, Disturbed, Not Found, Destroyed) Digital photo(s) if possible: (one close-up showing stamping and one showing immediate surroundings) Thank you for your inquiries and interest in updating the status of USGS control stations! Dale ( Dale Benson, email@example.com at the USGS ) =========================================== Quote Link to comment
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