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Black Dog Trackers

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  1. pgrig - We, as hunters, think of the marks as scaled because it has implications about searching with a GPS. However, to the people who wanted these marks established, they are thought of as vertical control. Vertical control is used in construction of roads, railroads, buildings, dams, water and sewer systems, etc. Railroads, for example, need to assure that they have (and maintain) minimal loss of energy. The NGS has some articles on this. Here are their introductory articles on leveling. This one speaks of the HtMod project - using GPS to increase height accuracy.
  2. The "rounded to the nearest second of lat/lon (+- 100 ft)" is the issue.Not only is it +-100 ft. even for adjusted marks, it appears to be simply truncated, not rounded. It looks like it might be good if NGS did a re-look at their perl script. Testing truncation versus rounding, I plotted the rounded (to the nearest second) values for the Disco Dan station: N 38 40 46 W 077 14 59 puts a mark 47 ft. NW of Disco Dan's white marker, nearer the woods. That is closer than where the NGS .prl script's values put it (apparently) at: N 38 40 45 W 077 14 58 which is 86 feet SE of the white marker on the ground. That one certainly does use the whole adjusted values. It puts its green dot right on Disco Dan's white marker! (Apparently Google Earth (and Google Maps) is pretty accurate around there.)
  3. billwallace - The reference-mark-with-a-PID thing is a different situation. The RMs' PIDs almost always have SCALED coordinates - they might be OK, and they might not. I've seen cases in which all RMs have the same (wrong) coordinates. Some programs look into the box score to rectify this problem since the box score information plus the coordinates of the parent tri-station together provide more accuracy. I know that both NGSREAD and NGS>GPX programs do this. (See the March 10 message for their URLs.) I don't know about other programs. As far as the DSWORLD apparent cut-off of decimal points, station SANTA F happens to not have large decimal portions.
  4. MRAS - Did you see the last paragraph of my March 9 message above? Did anyone else notice the issue? You can see the white triangle where the marker is very well by putting this N 38 40 45.75680 W 077 14 58.50337 in the Google Maps search box. DSWORLD puts its icon for the station here: N 38 40 45. W 077 14 58. (decimal parts cut off)
  5. I see that. It's the same with Virginia. HOWEVER !!! The statewide dat files have been updated this week!!!
  6. Hi SidewaysSam - You can read about that here. Hopefully that will at least answer your main questions. There are thousands of benchmark disks that are not included in the database, so it isn't surprising to find one that isn't. It's always an interesting thing to find, though.
  7. rtreit - Yes, I think that would be good. In my opinion, the best approach might be to start doing that in holograph's Benchmark Hunting Wiki, and get the authors to do some feature lists, pros, cons, and descriptions of the programs there first, then get it in the FAQ here in the next revision (whenever that is). Besides dsworld, bmgpx, and ngsread, there is monkeykat's Benchmark Viewer and foxtrot_xray's NGS>GPX program, and perhaps others. I would suggest broadening the scope from just Google Earth to all mapping resources for which benchmark software has been developed. For instance, Google Earth and Google Maps are sufficiently different that people use them for benchmark maps in completely different ways.
  8. It works just fine here. It's a good program! The links of course point to realtime datasheets. I saw a couple of 2007 recovery notes in a quick look in Fairfax County, Virginia, but I don't know the date of the PID list that it uses. I presume it is also realtime, but I'm not sure. rtreit, if you like Google Earth, you could try ngsread. It makes a .kml file for Google Earth from NGS county or state archives. The popups include all the recovery notes. I compared DSWORLD and ngsread with Fairfax County and noticed that DSWORLD included a whole new series of marks like this one. The mark was monumented in 2005 but wasn't in the 2006 county archive. Not particularly surprising, but it was interesting that it was part of a whole group of marks. The comparison was also interesting because it showed how this station had moved, I guess as part of the GPS adjustment. Yikes; waitaminute! I think something's wrong with the plotting of DSWORLD. Station Disco Dan with ngsread puts the pin icon directly on one of those plastic Y-shapes, clearly visible on the ground, but DSWORLD's icon is about 86.5 feet off (using the GE ruler). It's true that the adjusted coordinates are different, but only in the 0.001 second position. It looks to me like DSWORLD is plotting with values rounded to the nearest second. Well, that should't be very hard to fix.
  9. The hour-long averagings are interesting and your results look surprisingly good to me also. However, in looking for a horizontal control mark, hour averaging isn't what will be done, except possibly in the case where digging a lot is going to be required, and even then, the digging area, as per your graph, is going to be about the size of a king bed. Instead, a person will be holding the GPS receiver in hand and looking at its readings while walking around. This is why, in my experiment, I wrote down every change in readings while the unit was stationary (I also calcualated the average of the data). The readings wandered around a 4 foot square area. Unfortunately, as I was saying in the previous post, it was not the best place for the 4 foot square area. Does your unit have WAAS? Mine doesn't.
  10. I did a somewhat different experiment, testing the idea of using a GPS receiver for measuring a distance to a reference mark by calculating the coordinates of the reference mark. In my experiment, I used a long wall at the top of a parking lot with no roof. I didn't calculate coordinates, but instead I took lots of individual measurements, not averages, at several different distances along the wall that were measured with a tape measure. The results were pretty awful, sufficiently awful that I never published the results here. The GPS receiver, as I recall, wasn't all that bad at measuring the distance, but it was pretty terrible at measuring along a straight line. Some of the points it indicated were a few feet off the line. I still have the data written on some 3x5 cards.
  11. I was first going to say that Found Poor would be OK, but the more I look a the measurements, the less I think it's a find. It does look like a disk 'scar'. The metal in it is square not round, but that's OK, someone may have pounded a square rod in there. Lincoln Avenue doesn't look like a street that has changed in a long time, so the distance of what was found being 31.25 feet instead of 28.9 feet from the center of Lincoln Avenue is not a good sign. A very different difference from a metal enclosure isn't as bad since an enclosure can change. 17 feet versus 21 feet for the distance from the railis not a good sign either. The distance is too large, and tracks don't change that often, and when they do, it's likely that it would be more than 4 feet. The signal box has a sort of look of just sitting there. Maybe it was moved?
  12. There is also this reference on Holograph's site. It includes a beginners' section.
  13. Here is an older topic on the same subject (except with the Google Maps aspect).
  14. I wouldn't go so far as to say that. The GC database is a copy (not any kind of summary) of the NGS database in early 2000 (I think there are a few recoveries in there dated 2000). For some reason, perhaps on the NGS side, the copy didn't include any offshore parts of the U.S. except for Hawaii (no PR, Guam, etc.). There are some issues with how GC parsed in the database (mainly no box score), but if you click on "original datasheet", you'll see it's there in the GC copy that way. Since the 2000 copy, obviously there has been activity in the NGS database. There are some new stations, but not many. There are a lot of new recoveries, of course. There are also some maintenance (correction) actions that have taken place; duplicate stations resolved, cross-bred recovery notes fixed, and stations put into the destroyed category (you will see them in GC, but not in NGS regular data). The NGS site also includes the Ocean Survey disks, as I recall some of them are not in the regular NGS database. However, all that said, the basic number of datasheets is not all that different between 2000 and 2009. The main issue is the recovery reports between those years not being on the GC site.
  15. shotgunpr - Although they are all run by the same company, Groundspeak, geocaching, benchmark hunting, and Waymarking have independent 'counts' that do not interact. Geocaches' and benchmarks' counts are shown on the same website, but they don't add to each other's find count. Waymarking and all of its kinds of counts are on a different website. As far as benchmarks are concerned, the geocaching benchmark site has coordinates, descriptions, finding directions, and reports for over 700,000 marks already done for you. All you need to do is find them and report whether or not you found them, and make any updates. It's a bit more challenging in a psychological way than geocaches because many benchmarks are no longer there and have been gone for decades, yet you don't know it. Geocaches are very likely there since they were placed within the last few years by someone using a GPSr. The Waymarking benchmark site has no coordinates, no descriptions, no directions for finding. There's no measuring to find the marks, no figuring stuff out, no following your GPSr to find a goal, and little or no historical interest (unless you have a project to find a series really old survey marks that are not in the NGS site). It is mostly just plain finding, and reporting what you found and where, and you provide the coordinates. Again, the psychology is different; this time there's no assurance at all for you at all that any benchmark ever existed where you might be looking, with three exceptions; USGS benchmarks symbols on topo maps, section corners on topo maps, and state and local benchmarks sites that have coordinates and sometimes finding instructions similar to the NGS site. Geocaching, benchmark hunting in the geocaching benchmaks site, and benchmark finding on the waymarks site are 3 different hobbies, and their psychologies are not the same, so you might like just one, or two, or even all three. Different people like different things.
  16. Well that would rob us of all the recoveries done by those who do not report to the NGS and that includes some good recovery people
  17. I believe the amount of effort would be near zero - just a template change.
  18. For those of us that were here from the start of benchmarking here, we got used to using that 'original data' link because geocaching.com didn't parse in the box score, so clicking on the link would show the box score, if any. Of course now that more than 8 years have gone by, it's just too old to use since there's a significant chance that there are later recovery notes. So instead of just looking for a box score for horizontal control marks, we need to see the NGS format for all the kinds of marks. It would be nice if geocaching would add a new link to the benchmark pages - current NGS datasheet.
  19. I wouldn't bet on that either.Jeremy emailed me a bit over a year ago and said (as an aside to another topic) that they were again considering updating the regular benchmarks site with the latest NGS information. That was long after Waymarking started. I suppose by now this thought there has dissipated long ago again. Waymarking certainly wasn't invented because of benchmarks. Dozens of Waymarking categories existed before the benchmarks one did. I think Waymarking was invented because locationless geocaches were popular but that web platform concept wasn't big enough for what it could be. There's hundreds of theories of why Waymarking was started, though.
  20. Hi Mike, I'm unclear on what you mean exactly by "leaving some marks" and may be misinterpreting it, but I think it's an important issue. If you meant letting them physically stay where they are, then yes, leave them right where they are. (Here is geocaching.com's rule on that.) This is true partly because it's difficult for any of us to say whether or not the NGS would classify them as destroyed, since we don't work in their office. Also, the NGS owns the database, not all the marks. Hundreds of thousands of marks in the NGS database are not actually NGS or CGS marks; they are marks of the USGS and other federal and local agencies. An NGS classification of a mark as destroyed does not in itself mean go ahead and take them, even if it's to a historical society or something. Again, you can't be sure of what the NGS will say before you report to them. The nearby newer marks may be another type of control, the marks of other agencies, etc. You must leave these old stones exactly where they are.By the way, ten feet difference with a handheld GPS is not sufficient to say that it's in the wrong position. We can't tell the NGS to classify a mark as destroyed; we can only suggest that to them based on evidence we provide. They make the decision, not us. Whether or not you wish to log/report any of these marks to the NGS or this benchmark site is up to you.
  21. This is tricky stuff and it's easy to misinterpret these forum posts, perhaps mine particularly. On just the part about whether or not to say to the NGS that a station should be considered destroyed is quite different between intersection stations and all other stations. (Just for a quick review, an intersection station is a radio tower, church steeple, rocky mountain peak, water tower top, and other such things. Any disk, rivet, rod, etc. is not an intersection station.) For an intersection station, report destroyed if you don't find it when you are personally at its adjusted coordinates. For non-intersection stations (disks, etc.), report destroyed if you find it, AND it is out of it's proper position, like dug up and found lying on its side on the ground, fallen over a cliff and found at the bottom, etc. For non-intersection stations that you don't find, don't suggest to the NGS that they are destroyed no matter what proof it seems you have. Instead report NotFound and tell all of your proof in your report.
  22. Since the NGS has a way for recovery persons to indicate to it that a station is destroyed, then the NGS means for it to be used - with experienced judgement. Otherwise they would not have provided that means. Although Found and MarkNotFound and FoundPoor can be chosen in a recovery entry, there is no way to do that for Destroyed. There is no way for a recovery person to 'classify' a mark to the NGS as destroyed. Instead, it's a like advice or a suggestion to the NGS. The NGS must agree on the destroyed status and only they can classify a station as destroyed. If they don't agree with you, they can either ignore your input or put in a NotFound. The NGS has made it clear that they are ultra-conservative about their classifying stations as destroyed. If a station might be buried under 20 feet of dirt, that's not destroyed. If a mark is on an old bridge and there's now a new bridge nearby, the mark may be on some buried part of the old bridge abutment, so that's not destroyed either. A mark might be covered by a layer of asphalt, or a house, or any other thing, and that mark is not destroyed either. Oddly enough, only if you have actually found the mark, could you say to the NGS that it is destroyed. Marks that are both found and out of their proper monumented location are the only ones that the NGS allows a suggestion from a recovery person that they classify them as destroyed. This is a resonable position for the NGS to take with their database because data space is cheap. Intersection stations are a major exception. If the tower doesn't exist, the station is destroyed. That's it. If it's been replaced by a new tower and the old tower is gone, then the station is destroyed. Since we can't directly classify these as destroyed, and can only suggest to the NGS that they consider them destroyed based on our photographic evidence and experience known to them, I see no reason not to suggest 'destroyed' to them. There is really no such thing as NotFound for an intersection station. Found and Destroyed are logically the only options. If the description of the intersection station has useful information about surrounding stations, then it's the NGS's decision of what to do about that. I think we shouldn't avoid showing the NGS that an intersection station is destroyed if we can send in photograpic evidence.
  23. LSUFan - Here is a topic that discusses cadastral marks. There are a lot of excellent responses here by the professionals. In particular this one by jwahl is very interesting and informative.
  24. Yep, so some marks can be waymarked in more than one category. That's the way Waymarking works. It's up to you how many you'd like to use, if any.
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