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BuckBrooke

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Everything posted by BuckBrooke

  1. turbo, what evidence do you have for surveying with this object?
  2. Although they most likely won't be NGS disks, you might also consider contacting your county, state and DOT survey offices to see if they have disks in your area.
  3. I was just emailed by a Tribal cultural officer in Oregon, who sent me disk and monument pictures for a USC&GS State Survey disk. Luckily, the disk PC0182 was in the NGS database, and he confirmed that that was the correct station. The interesting thing, particularly for anyone in that area who wants to log this for the contest, is that it's a Double Not-Found. There are 2 USGS Not-Found reports in 1984 and a USPSQD Not-Found report in 1990. Double not founds might be worth more (a point or two) for the contest?
  4. Is that the first double find for Waymarking benchmarks?
  5. Greetings, Mike&Melanie, and welcome to the benchmarking community. You've stated you're a surveyor by profession, and we hope that you will contribute to the discussions we have in this forum. Please take the time to look at the FAQ for the Benchmarking group; many members of this community who are surveyors or have recovered a number of benchmarks (for the NGS or not) have contributed to that document. A growing site of information for benchmarkers is holograph's benchmarking wiki, which contains quite a collection of resources for those following this hobby. In regards to the benchmarks that we search for on www.geocaching.com/mark, this is a copy of the NGS database. As such, only a minute fraction of the disks are corner markers, quarter corners, etc. Most were put down by the NGS, USC&GS, state or city agencies. For example, most of the stations in my area in Albuquerque are New Mexico State Highway Commission disks. There is also a National Geodetic Survey discussion forum, to which Dave Doyle and others at the NGS regularly contribute. As an introduction, I'm a physics graduate student, measuring parallax to find the distance to a particular type of evolved star for my dissertation, and thus have some understanding, if not quite hands-on experience, with the techniques used in surveying. Again, greetings.
  6. I can redo my spreadsheets for specific states, including format that would be useful.
  7. I would guess in some cases that if it's a pavement/road issue that the disk you've found recessed is the main surface disk. If the roads are built up enough, it might have buried the station 6 inches (or more?).
  8. How about different disks? This is Klemmer's idea, but basic. Has to be PID, but you get a point for every other agency disk you run across. Of course, that's tough for folks that have cleaned out their areas. Age from last recovery is interesting.
  9. Relic Hunter, you can start off quick and dirty and just print off the Geocaching.com page for each benchmark, especially if it's been found on geocaching before. I still do that, but I check the real NGS page for each mark before I go out, to see if there's been an update and if there's additional info. Everyone develops their own technique after a while.
  10. Sorry to hijack your topic a little, holograph. As always, your work is cool. ArtMan, I recall a little bit of discussion about this in regards to predicting when geocaching.com would reach 100k "recovered" marks, which I think is marks that are logged as Found. In regards to the error rate of the number of PIDs that have Geocaching.com Found logs: I might have overstated the issue a little, but I bet that the error rate is something like 3-4%. This isn't the error rate in overall Found logging, which includes duplicate logs on the same stations, it's the error rate in overall stations described as Found. In going through the photo gallery and scanning around the database for the Agency benchmark list, I've run acros a lot of incorrectly logged stations, mainly ones logged by caching muggles who don't know what they're looking for. These are the usual problems (a wrong disk on a highly trafficked mountain, an RM recovered as the main station, and disks found while camping, that haven't been checked up on by a benchmarker). The error rate in the photo gallery, etc. is lower than 3-4%, but that's only the disks that have a photo I can compare to the person's log. In the photoless logs, there's often hints that they didn't get the right station, and then you can guess as to what fraction of the "Found the station" bare logs should be added in as erroneous. This ties into the "quality logs" discussion held a little while ago. By comparison, I would guess that there's probably a 1.5-2% +/- error in the overall number of logs submitted to the NGS over the same period of time as the Geocaching.com logs cover, mainly due to errors by the USPSQD and to a certain extent GEOCAC. I've sent in 2 or three erroneous reports that I know of (later corrected, and mainly NF, so...) in 870 NGS logs, so I've probably sent in a few that I'm not aware of. Also, I've had several duplicate logs/misnumbered logs that I've straightened out, from incorrectly submitting on the website. Not all of these are corrected. Stupid snow!!! This is usually the time of year that I can get out and recover while ya'll are stuck in the house, and we've had 18 inches here in Albuquerque, and it's still in the ground in the places where I want to benchmark.
  11. Paul, in regards to time of day, the two things that might affect the signal are constellation geometry (as you said) and ionospheric turbulence/interference. 1) For geometry you want the satellites to be well spaced, not tightly clustered. The more tightly clustered the satellites in the sky, the more redundant the physical solutions, because the circles created by the solutions nearly overlap; thus, your positional accuracy is worse. 2) With a little bit of a guess regarding the ionospheric interference issue, we know that the GPS signal is around 1.2 and 1.6 GHz (24 and 18 cm wavelength), in L band (thus the L1/L2 and so on designations). These frequencies go through the ionosphere, but there's turbulence, interference and reflection (radio skip transmitting bounces off the ionosphere) The ionosphere expands and is more disturbed as it's heated by the Sun during the day, and cools off/contracts rapidly in the evening. So, I would guess that the best time to observe during a day is midnight to 8 AM or so. Even though as mentioned much of the ionospheric problems can be corrected by dual frequency comparison, I bet accuracy does degrade during the day. Also, the winter's probably better than the summer, because there's less solar heating of the atmosphere during the winter. Steve Randall talked about making GPS observations in the middle of the night, though it was probably more for satellite geometries.
  12. As a quick, slightly related note, geocaching.com just broke 90,000 PIDs found. Actual PIDs found (I would guess) is more like 85,000. Congrats to all.
  13. A lot of the unknown disks that people post here in the forums are USGS disks. There are chains of them in New Mexico that aren't in the NGS database; I've copies of a few quads around Albuquerque. Most of the disks do not have associated Xs. I would echo DaveDs comments.
  14. I use Excel spreadsheets, of which I am very fond, because they readily import .csv files, the output of various programs that mess with datasheet text files.
  15. The horrors of not having Internet access...*cough*...oh, I'm sorry, that was the armchair warrior in me speaking out through the keyboard.
  16. Cheryl's retiring pretty soon; I'm not sure who's replacing her, or when.
  17. I have "unofficially" received my copy. The wife got it for me for Christmas; thus, having had it pass through my hands from the post-lady, she has received a package from Berntsen that suspiciously looks like (obviously is) the book. Waiting for Christmas... *twiddling thumbs*
  18. I've reported all (or nearly all) of the stations between Albuquerque and Socorro, NM. Now that I'm regularly driving the interstate, I noticed survey crews at a lot of the stations in September, and now all of the stations are flagged w/ pink ribbon. Kind of made me want to get a spool of pink ribbon with www.geocaching.com GEOCAC printed on it and flag stations myself.
  19. An alternative hypothesis is that it is the 49th disk in the series, and the dot is the point of measure.
  20. Looking back at the last 6 months, I haven't been getting much benchmarking done, due to changes with my dissertation. However, I've noticed that I'm going out for longer runs on fewer days. I think this is due to the fact that I've hit the nearby population centers (need to head up to Santa Fe, an hour away), and so the benchmarks are now strung out along highways. I used to print out 10-20 marks in a quadrant of Albuquerque, and cover those in a morning. Now, I drive 45 minutes to an hour to the start of the run, hit marks for 2-4 hours and then drive back. I have the occasional hot spot when I travel, such as St. Louis, SE Minnesota, Boston, Miami and Dallas/Fort Worth, but those are separate from "day to day" benchmarking. Has anyone else noticed their benchmarking patterns change over the course of time/years?
  21. Hmm, I may not have been phrasing it right. The current radial searches require coordinate inputs. I would like to input the PID of a station, say FO0734, and the web page would use the station's coordinates.
  22. Will (seventhings) has kindly provided information and pictures for the following Lewis & Clark markers: #21 Milk River, MT #26 Fort Clatsop, OR #27 Lewiston, ID #28 Pompey's Pillars, Billings, MT #29 New Town, ND #30 Captain's Return, St. Louis, MO There are apparently a a good number more disks out there (the small ones). Stephen Randall should be sending me info.
  23. I would like to do radial and box searches based from a central PID. The page might read: Search 25 miles from PID # AA1234.
  24. 2happy, Well, I have good news and bad news for you. There is no easy accessible site like Geocaching.com for Canadian Benchmarks. On the other hand, Canada does have a national geodetic organization, the Canadian Spatial Reference System website, under the Department of Natural Resources. This is the Great White North version of the NGS in the US, and you can log with them and find marks, just like in the US. You can look up marks near you, or wherever you're going.
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