+SuperMadCachers Posted February 5, 2003 Share Posted February 5, 2003 the other day I ventured out into our bustelling city to find a few benchmarks. I have to say that I felt a bit strange walking through parking lots looking for these things. I never did find any as I'm convinced that the given coordinates are way off. I think I'll only shoot for benchmarks out in the middle of nowhere from now on so as to not appear as a car thief. www.larsenfamily.com family@larsenfamily.com Quote Link to comment
Cholo Posted February 5, 2003 Share Posted February 5, 2003 quote:Originally posted by SuperMadCachers:the other day I ventured out into our bustelling city to find a few benchmarks. I have to say that I felt a bit strange walking through parking lots looking for these things. I never did find any as I'm convinced that the given coordinates are way off. I think I'll only shoot for benchmarks out in the middle of nowhere from now on so as to not appear as a car thief. Does this have anything to do with your proximity to Roswell? Making a mountain out of a watermelon. Quote Link to comment
+OzzieSan Posted February 6, 2003 Share Posted February 6, 2003 quote:Originally posted by SuperMadCachers:. I never did find any as I'm convinced that the given coordinates are way off. You are correct. Depending on the type of BM you were in search of the coordinates may be of little use. If they were vert controls then I have found it is almost always best to use the data sheet. If they were horizontal controls and have had coordinates updated in the past few years chances are good the coordinates will be very accurate. Quote Link to comment
+Webfoot Posted February 6, 2003 Share Posted February 6, 2003 quote:I think I'll only shoot for benchmarks out in the middle of nowhere from now on so as to not appear as a car thief. I know where a couple of benchmarks are right near where I live - one's embedded in the curb near a local church - I haven't even logged that one as I haven't had the time to go and take the picture and get the notations from it. For whatever reason, my initial response is to leave benchmarks alone and not go out and find them unless I happen upon them in my travels. I figure if I'm hiking somewhere and come across one, I'll note it, take a picture of it and then log it when I get home, but I don't think I'm going to actively going to go out and look for them - probably for the same reason you've noted above. Webfoot One of my hobbes? Tromping through the underbrush looking for Tupperware containers. Quote Link to comment
+embra Posted February 6, 2003 Share Posted February 6, 2003 We each have personalized ideas of what is fun and what is not...but if you haven't tried it, I'd suggest plotting out a series of a half-dozen or so benchmarks and spend a few hours in pursuit. I have found the activity surprisingly rewarding...so much so that I prefer it to cache hunting. The fact that they aren't always there is one of the things that brings an extra measure of satisfaction when they turn up. I'll also allow that the easy finds are not nearly as satisfying as locating something that you are thinking for a spell just ain't gonna be there no more...sometimes the satisfaction comes in figuring out an error or inconsistency in the data sheet description. I have discovered there's more than meets the eye to this enterprise. Max Often wrong but seldom in doubt Quote Link to comment
SURVEY0R Posted February 6, 2003 Share Posted February 6, 2003 Just a few notes about coordinates and datums... The NGS data sheets give 3 types of coordinates: - LAT/LON in D/M/S - State Plane Coordinates - UTM (Universal Transverse Mercator) It should be noted that these coordinates are adjusted to the NAD83 datum. If you are scaling coordinates off of USGS Quadrangle maps or off a website such as TOPOZONE.com, these coordinates will be on the NAD29 datum. If you are using Lat/Long in D/M/S, the difference between NAD83 and NAD29 (in my area) is a grid shift of approx. -750' in the Northing and +10' in the Easting. (This could be why you are not finding anything) Set your datum in your GPS unit accordingly. Another thing, locating coordinates using D/M/S is not very accurate. One second of Latitude = 109'. Puts you in the ballpark, but you have a large search area. (Another reason why you may not be finding anything) I find that using UTM is a more accurate system. UTM is in meters. 1 meter = 3.281 feet. Most GPS receivers w/ WAAS enabling say that the positional tolerances of their units is <3 meters. I can verify this as I have been averaging about 1.7 meters [or approx. 6') to known NGS monuments. Again, if you use USGS Quad maps or TOPOZONE, and you want to convert the coordinates from NAD29 to NAD83 - here is a link to CORPSCON, the Army Corps of Engineers computerized toolbox to convert datums and coordinate systems. http://crunch.tec.army.mil/software/corpscon/corpscon.html Don't sweat it. It took me a couple days to figure out the datum shift myself. Good luck, and let me know how it goes. [This message was edited by SURVEY0R on February 06, 2003 at 07:27 PM.] Quote Link to comment
+Webfoot Posted February 7, 2003 Share Posted February 7, 2003 quote:Originally posted by embra:We each have personalized ideas of what is fun and what is not...but if you haven't tried it, I'd suggest plotting out a series of a half-dozen or so benchmarks and spend a few hours in pursuit. I have found the activity surprisingly rewarding...so much so that I prefer it to cache hunting. When I can squeeze a couple of free hours into my day, I may take you up on it and try to find some of them. Webfoot One of my hobbes? Tromping through the underbrush looking for Tupperware containers. Quote Link to comment
+EMTJeepers Posted February 7, 2003 Share Posted February 7, 2003 I was searching for two at night, and a cop pulled up right behind me. I had my camera out & GPS, and was cleaning out the hole where the benchmark was. Stood up, snapped the pic, thats when I saw the officer in his car, he just turned the corner and kept going. I figure between the gps & camera, he figured I was a surveyer looking for markings?? Quote Link to comment
+Webfoot Posted February 7, 2003 Share Posted February 7, 2003 quote:Originally posted by embra:We each have personalized ideas of what is fun and what is not...but if you haven't tried it, I'd suggest plotting out a series of a half-dozen or so benchmarks and spend a few hours in pursuit. I have found the activity surprisingly rewarding...so much so that I prefer it to cache hunting. After reading some of the descriptions of the markers around me, I'm now finding this kind of interesting. There's one very near a virtual cache that I helped a guy in Missouri set up. Nice thing about them is they are so abundant, you don't have to wait for others to hide them like a geocache, just step out your door and you might find one on the curb near your house. Thanks for the encouragement. I'm taking my boy out shopping tomorrow and we might do a couple of these while out running around. Now I'm really glad I got my digital camera this Christmas. Webfoot Tromping through the underbrush looking for Ammo cans & Tupperware containers. Quote Link to comment
+Poindexter Posted February 7, 2003 Share Posted February 7, 2003 quote:Originally posted by SURVEY0R:Just a few notes about coordinates and datums... It should be noted that these coordinates are adjusted to the NAD83 datum. If you are scaling coordinates off of USGS Quadrangle maps or off a website such as TOPOZONE.com, these coordinates will be on the NAD29 datum. Most USGS quadrangle maps are in NAD27. Some are in NAD83. Maybe your just making a typo but I thought I'd correct you for those who may be looking for NAD29 on their receivers. Quote Link to comment
SURVEY0R Posted February 7, 2003 Share Posted February 7, 2003 Thanks for catching that Poindexter. Seems I created a new datum there.... Quote Link to comment
+Webfoot Posted February 8, 2003 Share Posted February 8, 2003 quote:Originally posted by Webfoot:After reading some of the descriptions of the markers around me, I'm now finding this kind of interesting. There's one very near a virtual cache that I helped a guy in Missouri set up. Nice thing about them is they are so abundant, you don't have to wait for others to hide them like a geocache, just step out your door and you might find one on the curb near your house. Well, we went out looking for a couple of them today. I thought I knew about one that I had seen on a curb awhile back. Turned out it was a city benchmark. The other two were failures mainly because we didn't print out the official histories of the benchmarks. GPSr had us looking in places where it couldn't be and then after getting home and re-reading them, I realized my mistake. Selective memory as one ages is a pain sometimes. I'm thinking about going back and looking for these again as it's interesting. Once again, thanks for the encouragement. Here's our log for one of them. Wasn't thinking very clearly on this one and had I been, I would have found this one.Not found - for now Webfoot Tromping through the underbrush looking for Ammo cans & Tupperware containers. Quote Link to comment
+SuperMadCachers Posted February 10, 2003 Author Share Posted February 10, 2003 Does this have anything to do with your proximity to Roswell? perhaps! www.larsenfamily.com family@larsenfamily.com Quote Link to comment
+embra Posted February 10, 2003 Share Posted February 10, 2003 quote:Originally posted by Webfoot:I'm thinking about going back and looking for these again as it's interesting. Once again, thanks for the encouragement. Well, here's some more, Webfoot. I'll tell you right now that the ones that give me the most satisfaction are the ones I couldn't find the first time. The data sheets are a must (as you've discovered). The descriptions are really intended to be the way to find them again; the GPS usually is just handy to get you in the vicinity. You can copy datasheets into a multi-columned Word document with a small font to get several datasheets on a single page. I like to use the Geoclipping applet to get the information into my PDA. And do be sure to have a number of BM's to hunt. Some probably won't be there, but it's less likely you'll strike out on every one. Max Often wrong but seldom in doubt Quote Link to comment
SIMPSON Posted February 23, 2003 Share Posted February 23, 2003 Finaly an explanation- This BM searching has been driving me NUTS! I went out one day to search for several and was 100% dissatisfied. The only ones I have found were by accident and then trying to log the pieces of crap are close to impossible! Any helpful hints??? SIMPSON - Bakersfield, California Quote Link to comment
rusty0101 Posted February 23, 2003 Share Posted February 23, 2003 quote:Originally posted by SIMPSON:Finaly an explanation- This BM searching has been driving me NUTS! I went out one day to search for several and was 100% dissatisfied. The only ones I have found were by accident and then trying to log the pieces of crap are close to impossible! Any helpful hints??? SIMPSON - Bakersfield, California Take a look through the benchmark gallery, and see what some of the benchmarks you are looking for look like. They change from decade to decade, location to location, and depend upon whom places them, and for whom. You are going to be really flumoxed if you think that you are looking for some sort of medalion, and the data sheet actually specifies a nail, or scribed cross. If you use your GPS to get you to within an eighth of a mile of the benchmark, that's about as close as it will get you. Start using the data sheet to figure out what the close reference points are. Recognize that some benchmarks are not where they were placed. For a variety of reasons, some are destroyed, some are just overgrown. Some have been removed for various reasons, some legitimate (road construction for example) some illegal (vandalism). Some local references don't exist any more, or have been altered. If a road has been widened, and the data sheet specifies a distance from the centerline of one lane, the measurement will be off. That is one of the great things about doing this kind of hunting. When you find a mark, if you take good notes, you can provide feedback to the system to make it easier for the next group of people who will use these marks profesionally. Also take note of any special notes in the data sheet with respect to people to contact. If you start looking in rural areas, you may need to contact local farmers, or businesses to gain access to some benchmarks. It is also possible that you will gain some extra knowledge of the benchmark and the surounding area. Most importantly, be safe, and have a good time. -Rusty Quote Link to comment
+Webfoot Posted February 26, 2003 Share Posted February 26, 2003 quote:Originally posted by embra: Well, here's some more, Webfoot. I'll tell you right now that the ones that give me the most satisfaction are the ones I couldn't find the first time. Embra, I have to agree. I've actually found that for something like this, it's more enjoyable to go out with others who share simliar interests in finding, or not finding as the case may be, the benchmark. This is one that we were able to document particularly well. I found the detective work involved in figuring out what happened to the landscape since the last time the benchmarks was noted in the NGS database is most rewarding. Sure it's fun finding the ones that are out there, but noting the unfound ones and figuring out the puzzle as to why it's not there anymore is more fun imo. Webfoot Tromping through the underbrush looking for Ammo cans, Tupperware containers, & little round disks. Quote Link to comment
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