Jump to content

evenfall

Banned
  • Posts

    788
  • Joined

  • Last visited

Posts posted by evenfall

  1. Spoo,

     

    You are correct, the consumer grade technology is becoming more accurate at the consumer level price point. This is a very good thing! But as I said, It is because of the technology you hold in your hand, not that of the network. The network with the right gear can get you to the single millimeter. As Geo pointed out in his original post, before SA was turned off, if you had any accuracy at all you had to verify it up front at a known POB and a sync up with DGPS. You could just acquire DGPS on the fly and all but to be sure, many chose to use a known start point. So no argument there! :-)

     

    WAAS is nice when you can acquire it. Sometimes you get more than one signal, other times none. It will only accurize the Consumer grade so much. With only what you have, you only have so much. But it is enough. I don't see a lawsuit problem though, because it is not the manufacturer that certifies the measurement taken, it is the end user. Further the only people who are legally certify a land measurement are Licensed Professionals such as Surveyors and Engineers. That is a critical distinction. The person holding the license is the only one who can certify anything which will hold up legally. It is a very definite criteria. The Onus is on the professional. The equipment or technology of any kind is simply the professionals tool of choice.

     

    For those who may want to observe this closely, project a few waypoints to local NGS triangulation stations. Use NAD 83 Datum and the Degree Minute and Second format (dddmm.sssss). Also, remember to use the real NGS datasheet. Make sure the data you use is not scaled. Try to enter them to the nearest resolution you can. Most will resolve to two places to the right of the decimal in a consumer grade GPS, though the datasheet will resolve to five places or more. you should round up if 5 and over, down otherwise. This will be close enough. The nice thing is that this way you will have places to go in the field wherever you are should you feel the need to check your accuracy. Either way, the unit should be fine if it is working properly and there are lots of people working 24/7 to make sure the network holds up their end. For the most part, and particularly with the consumer, single channel units with or without WAAS correction, testing against a POB is not all that necessary anymore.

  2. Boundsgoer,

     

    You are correct, The BLM has set a lot of bearing trees. Here in the Puget Sound area, I have found quite a few set by USGS as well. In Western Washington, there is not near as much BLM Survey here as there is in Eastern Washington and other States. This is a Coastal and Mountainous area and the USGS set a lot of survey in this area for their mapping programs and topo work down through the years. A lot of it was Bearing Tree. Lots of trees around here! Due to the Coast and Puget Sound with all it's many Islands, there is literally a ton of NGS work in the ground here locally too. Usually there is more leveling than triangulation almost anywhere you go, but in these parts both are on par or maybe even more triangulation in some areas. When you include landmarks to the list in third order horizontal control alone, you could just about swim in triangulation. Especially about 75 years ago.

     

    I think I did say in my previous post that I didn't think we would find many Bearing Trees in the NGS database as it is primarily involved with a different mission. Geodesy. Trees are not a stable monument for geodesy, They just wont work well for triangulation and leveling work, though they have been suitable for PLSS work forever! :-) I have driven a few railroad spikes in trees over the years for use as a TBM as well, but that was usually the end of the level line I ran for the purpose and it was primarily used as a TBM for Construction Laser calibration...

     

    As Surveyors we both know that we could go on and on about how many types of survey monument could be found in the field, but for the purpose of geocaching there is only one kind that matters. Primarily that of the NGS database and that which has been submitted to it, that passed the stability to be included in it. You would be surprised how many people find monuments of every kind in the field and do not understand why they cannot use it for geocaching, and why it will never qualify for geocaching. That was just a quick explanation, most of the answer is more than most people want to know.

     

    Rob

  3. Hi Geo,

     

    Well, If it well help you to know, these days since SA was turned off, you really could skip the step of going to your P.O.B. and calibrating as well as comparing. That 5 feet you are seeing is pretty standard for consumer grade accuracy. it really is something you should feel you can count on. Besides, these things are pretty self calibrating now as far as the network is concerned, and so is the end user gear. This could save you time, if you like.

     

    Moving at most any speed, the satellite will track up quite nice and exact, but you need more than four birds to do it well. It is important to note that our government has some rather large cylindrical rocket powered objects that count on this as well as some other things that fly high and faast. Did I say faaast? well I meant faaaaaaast. So, no problem there. We are not trying to acquire the location of a Millimeter at that speed anyway.

     

    You are doing fine Geo. Happy Bench Mark Hunting.

     

    Rob

  4. Thumper,

     

    The Geocaching game Of Benchmark Hunting is primarily based on monuments that were placed in the field by the National Geodetic Survey. Early on, This same agency was known as the Coast and Geodetic Survey... Anyhow, they are the developer of the Database that Geocaching uses.

     

    The USGS, US Geological Survey is a different agency all together, yet they too have a lot of survey out there you may find. Some of it was submitted for inclusion to the NGS but most was not. They were the primary user of bearing trees for their data and survey purposes. You will not find too many bearing trees in the geocaching database because they were not in the NGS database. And a good many other monuments in the field will not be in there either. Most of these agencies do not share all their data with one another, as the data is for use in different missions and uses different criteria for the settings.

     

    The best way to hunt a Benchmark is to first, look for what is in the field where you will be hunting by looking at the geocaching.com benchmark page. Just add your zip code or latitude and longitude and it will tell you what is available for you to hunt and file a find for. if it is not in there it is not part of the game.

     

    For a more detailed explination, Have a look

    Here.

     

    Good Luck Hunting!

     

    Rob

  5. Geo,

     

    Most all GPS download ephemeris data from the satellites which is corrected by the USAF at Schriver AFB near Colorado Springs Colorado. They will issue notices if there are Satellites are off the air or outages will affect accuracy but this is rare, maybe a few times a year. We can overcome the outages if we have time to wait and it is usually not enough to matter for most purposes. It may matter if you are trying to do something very accurate at say 600 MPH if you know what I mean... This ephemeris data will tell the GPS where all the birds are which are and are not available in the constellation, What Coordinated Universal time is, all the synchronizing timing etc, all so the radio triangulation can happen...

     

    All timing between the birds is atomically accurate with Atomic clocks on each bird and synchronized from the ground. For dual channel work we can pull more than one signal from the birds and with DGPS from the US Coast Guard in many locations nationally we can correct for Ionospheric distortions, and we can also set up a DGPS Local network for local sitework. With Real Time Kinematic (RTK) GPS we can set up and let it run for hours to get a fix from many birds and this can accurize things even more if need be. But we can see right from the computer on the GPS how accurate we are and if that level of accuracy is acceptable to us. If we want more accuracy, we simply wait longer, if it is that important to do so. In Geodetic work it would be. Setting a construction staking point for a concrete floor would not. So for the most part it is not something we really even think about anymore. The Pro gear will tell us if we are good to go or not.

     

    On consumer grade stuff, the accuracy resolution is really only +/- 5 feet anyway. Close enough for horseshoes and hand grenades. Using it, I figure I could hit my car with a horseshoe if I needed too. :-) As for consumer grade GPS mapping, well, I am not even sure what datum they really use, but that would surely explain all the little tracking errors. I Run NAD 83 in my GPS and I see tracking errors in the mapping all the time. Not bad but who knows... I have WAAS correction then I don't, then I lose track on a bird or 2, and the accuracy goes up and down, all the while I am on one datum, and the onboard map is of another, except for when it is not. See? It is all relative in the consumer end. For the most part they work well enough and we are not lost. All that is due to the lack of accuracy that is not built into the consumer GPS in the first place, not a matter of GPS constellation accuracy. It is still close enough to get you to a Hiding Triangulation Station!

     

    Overall Geo, there is more to all this than I have explained but anyone can easily study up if they like. This is really more of a GPS topic than a Bench mark Hunting topic anyway. These days, it is something the USAF and USCG concern themselves with more than anyone else does anymore. We are post Selective Availability now. The lacking accuracy if any would be too small for most users to ever realize, and in the cases we can reveal it, Most all GPS units will tell you the kind of accuracy they are able to render at any given time. For Pro gear, a reading taken over time will get us where we want to go either way.

     

    Rob

  6. ddnutzy,

     

    My Opinion? It is never safe to assume anything. But here is what we can deduce... :-)

     

    I pulled the NGS Datasheet for MZ1556, PEAKED MOUNTAIN. it is Third Order Triangulation. NAD 83(1996)- 42 02 50.77368(N) 072 20 24.68076(W) That should be accurate to within one inch or less. I would load those coordinates in my GPS by projecting a waypoint and run a Go To, to help find the Station. The problem is, consumer grade GPS with WAAS correction is only good to 5 feet. This Drill Hole could be there, just filled with dirt from rain and weather. It may no longer look like a hole. These Drill Holes were commonly only 1/2 inch in Diameter, and only 2 inches deep, and drilled or chiseled by hand, so it may not be a very deep hole. The NGS Datasheet for MZ1556 says this is a Drill Hole Monumented in 1885, it was not found in 1935. It does not say that a disc was later placed in this Station. It has not been found since. Another Station was referenced in the narrative description of the NGS Datasheet for MZ1556, PEAKED MOUNTAIN 2

     

    MZ1557, PEAKED MT 2 is First order Triangulation. NAD 83(1996)- 42 02 50.77537(N) 072 20 24.68424(W) This should be accurate to within a half inch. You can see the Station Coordinates are different. There are in fact, two stations there, and within 6-10 feet of one another. They are not the same.

     

    Interestingly and of note, The Geodetic Surveyors who described Peaked MT 2 in 1901 mention finding Station Peaked Mountain, but they did not submit an official recovery for it at that time. Station Peaked Mountain has not been officially recovered since 1885.

     

    Ok so here you go. I see you have already done most of this but here is how anyone could do it. Go Find MZ1557, PEAKED MT 2, set your GPS To NAD 83 Datum, Degrees Minutes and Seconds Format, dddmmss.s, Then set it up to do a Go To, to 42 02 50.8 (N) 072 20 24.7(W) rounded up to nearest decimal. When one finds it, please take a photo of this station as it is of a very rare type You will know one when you see it as it has a star of david type star in the center of it instead of the usual triangle: THIS IS AN OCCUPIED FIRST-ORDER STATION MARKED BY A STATE SURVEY STANDARD MAGNETIC STATION DISK STAMPED PEAKED MOUNTAIN 2, 1896 SET IN A ROCK. I have confirmed this from the photos in your recovery last year. This is a station that was at one time used to measure the Earth's Magnetic Field. Those were a pretty rare type of Station. Congrats on that.

     

    Hunters Should find The Station Mark, RM2 and RM3 as brass discs cemented in drill holes. You did find the station RM1 and 3. You should find RM1 as a shank with a pried off disc in a drill hole, still fully functional as an RM in that condition, and RM4 was never monumented as a Brass disc, but it should still be there, it is a drill hole 23.26 Ft or 23 feet 3 inches, bearing due Northwest of the Brass Disc Station Mark called PEAKED MT 2. No one has recovered RM4 since 1977... No Geocacher has submitted a clearly legible photo of RM2, and no photo for RM4 as yet. All four of the reference marks are easily verified with a compass and a 50 foot tape measure, you could get by with a 25 footer if you skip out on doing a direct measurement to RM3. A helpful hint here, if you do find RM4, it could be indicative of what Station Peaked Mountain may really look like.

     

    To find PEAKED MOUNTAIN, PID MZ1556, take your tape measure with you and an Ice Pick or leather Awl, if you have one, a 16d nail if you don't. A stiff putty knife could be helpful, and a compass calibrated for Magnetic declination (Declination = 14° 52' W changing by 0° 0' E/year) will help too. From the Station Disc Peaked Mt 2 pull your tape measure out 10 feet due east (True) of the brass disc and if you have chalk, or something you can lay down at the location there like a small rock, make 2 marks one at 6 feet and one at 11. Then while holding your tape measure on the station disc, sweep the tape measure to the south and stop when you get to the Due Southeast Direction. Again make a mark at 6 feet and 11 feet. Somewhere inside that pie shaped box, based on the differences in the two coordinates I would say ESE of the Station Peaked Mt 2, should be the Station Peaked Mountain, A drill hole.

     

    Now, I know you found a hole to the west of Peaked Mountain 2 that you thought might be the drill hole for Peaked Mountain, but lets compare the station coordinates. Do you see how the numbers are larger on Peaked Mt 2 than they are for Peaked Mountain? Particularly to the right of the decimal point? This means that Peaked Mt 2 is slightly further north and west of station Peaked Mountain because when dealing with North Latitudes, the numbers are larger the further north of the equator, and and with West Longitudes, the numbers are larger as you go west of Greenwich England. Some people may not realize this but comparing the numbers can give clues to direction and distance. Since Peaked Mountain is a smaller number in both axis's I believe it is ESE of, meaning a greater distance east than south of Peaked Mt 2. Even the CGS described Station Peak Mountain as being 10 feet east of Peaked Mt 2 in the 1901 recovery of Peaked Mt 2. That concurs with what the coordinate comparison seems to say. It may sound silly to be described as being on a pinnacle, but it was not described as being on top of the pinnicle. The 1934 recovery seems to indicate that where the station would be is 3-4 feet lower in elevation than Peaked Mt 2. If it is not obvious, take your awl and putty knife and dig and scratch around inside the pie shaped area you laid out, it should be there. You should by rights see the chiseled triangle even if you don't see a drill hole. But like I said, perhaps full of soil or overgrown with lichen. If you find it, and it may not be easy to see it first, you will be the first to do so, officially, since 1885. This is what the Station Coordinates, taken in comparison tell me, and if accurate it should be right, but we find errors all the time. Sometimes numbers become juxtaposed, subtracted instead of added and all sorts of things... I agree with your statement, "a drillhole in granite is hard to destroy I'm sure that it is still there". I think so too. It is possible that it could be not located but it isn't destroyed.

     

    One thing that could be done to help future recoveries of the drill hole is to take distance measurements with bearings from the various brass discs in the area (at least 2, 3 would be better) to the drill hole which is Station Peaked Mountain, and in so doing, recording the results to the description of MZ1556 Peaked Mountain, so it can be improved for future use.

     

    From here I see the need for a good photo recovery of RM2, and a recovery for RM4 on PID MZ1557, and a recovery of any kind needed on MZ1556. Both for Geocaching, and even for the NGS if one likes. If for no other reason than to find it as a find for geocaching, this should help.

     

    Good Luck!

     

    Rob

  7. Edscott,

     

    Here is a link to a post I wrote while back concerning why some survey markers were not on geocaching.com. You can read it Here.

     

    One way you may find it more efficient to hunt Benchmarks is to do a zip code search or a Latitude and Longitude search of the area you intend to be geocaching in, just in case. It will guide you to what is worth hunting and what is not. If it is not listed, it is not worth hunting for geocaching scoring purposes. You can find that page Here.

     

    Enjoy!

     

    Rob

  8. Meters to Feet is taken by dividing the number of Meters by 0.3048 for Feet.

     

    F= M / 0.3048

     

    Feet into Meters is taken by using the same factor 0.3048 as a multiplier of Feet.

     

    M= F x 0.3048

     

    Often confusing, only when you think that a Meter has 3.2808 feet in it, but that number is not used in your formula. It also has 39.37 inches in it as well, but that number is not used in your formula either. Both of those numbers can be derived as a result of the formula.

     

    0.3048 is the only factor you need.

     

    Rob

  9. That is a great example Ted. This Station is a Bench Mark. We can see this from the Datasheet that it is highly accurate Vertically, and it is Scaled Horizontally. Your GPSr fix will be helpful to those in the future seeing to locate this Station. If the Horizontal component is not scaled then the GPSr fix would not be necessary. Your recovery actually improves the description for this Station. It really is that simple.

     

    Thanks Ted. Your recovery shows how easy a recovery can be, and yet if it seems too difficult sometimes on a case by case basis, there is no obligation to submit any recovery at all. In fact one could just claim a find on GC.com if that was all they wanted to do. Plus if they wanted to, they could bring the challenging recovery into the forum and we could all try to help sort it out as we have in the past. There seem to be a lot of people here who would be more than happy to give it a try.

     

    Rob

  10. Hi Dave,

     

    Generally we would not seek to "occupy" the vertically mounted Station with a Theodolite, or a more modern, computerized version which we call a Total Station. There are a number of ways we could use it.

     

    A Bench Mark in the strictest engineering definition is a reference mark for vertical measurement, and are said to be a known elevation. It is not uncommon to see a Bench mounted vertically. I have never come across a Triangulation station mounted vertically myself but I can't rule out that it may have happened. Latitude and longitude do not measure the vertical axis. A survey tech rodman may measure from the crosshatch on the BM to the ground by direct measurement with a tape to determine the elevation on the ground then take the shot to the prism pole and prism from the ground and use the difference measured in the calculation. They could add that length (from BM to ground) to the prism pole to compensate for the ground level, They could hold the tip of the prism pole at the same level as the BM in the air and take the shot, or they could radio the measurement to the survey tech instrument-man or party chief and they can compensate with the measurement entered to the total station. All these methods will get basically the same result.

     

    The distance to the BM Station in the purest sense is not all too important as these Stations are most commonly considered elevation only, but with modern instruments we can take a laser ranging measurement with the Total Station or robotic derivative thereof and it will know and record the distance to the prism pole on any shot we choose.

     

    Rob

  11. Oldfarts, John,

     

    I think you are missing my message, so let me help you understand me better.

     

    I know you and Shirley Like to Crow, show pictures of your finds, that you are accumulating finds, that you enjoy to see this as a somewhat competitive hobby and you love to have fun. I have thought that the way you approach this hobby is wonderful use of the hobby. I share your excitement and enjoy the posts you make. I don't think you should recover any to the NGS if you don't want to. Your choice of use is fine with me. I am also impressed that you want to help others learn how. That is cool. But I see others here who want to take advantage of the alternative ways of finding Benchmarks too. Some are learning about the Colorado State Line, some are discovering the existence of NGS settings deep in Canadian Territory. They do this differently than the way you choose to but that is all good, as there is plenty of room for all the aspects of this hobby here.

     

    >How close does a surveyor have to be to use an intersection station?

     

    As a Surveyor I have to be able to see the Station with my instrument. I as a Surveyor am charged by law to be as accurate as I can be. Do I give close up eyeballs to stations I intend to turn angles on as landmarks before I use them? You bet I do, and then I take my shots and compare my data, It had better match the datasheet. If not, I may have to choose something else or use it and adjust it..

     

    >How about a benchmark disk?

     

    Same deal, I described this to you when we discussed the one you found under a pile of rocks. For the most part, I need an instrument set up over the station, the instrument needs to be able to "see the Station", a stable, safe setup preferably, but we don't always get this, and it needs to be able to be seen from all the angles I need to record.

     

    >If you can see an intersection station from 5 miles away and recognize it there is no problem logging a find! Like the surveyor, with a disk, you need to be close enough to "ID" the mark to claim a find.

     

    I suppose if someone wants to play that way for the game, then that is up to them. I am not policing anyone, but I have already stated how I feel about it. I believe Seventhings did a great job of describing a thorough method for recovering a Landmark earlier in this thread. If we can use any method however, I hereby claim all geocaches in the State of Washington, by virtue of residency here! It doesn't seem like I should be able to do this but since I am able to play by my own rules then what the heck right? I can be like a politician, I can state whatever I want to be true for me and leave it to the rest of the world to spend all their time proving otherwise. To be fair, Just as I would have to recover and find the Disk, I should also recover the landmark. As an NGS recovery there is no way I could recover anything from 5 miles off and make an adequate recovery, and to be honest, I feel that method would lack integrity in gaming too. If all the integrity goes out the window, then eventually there is no game.

     

    >Why does it matter so much if the "recovery log" is only on Grounspeak? Is it really necessary to tell every Newbie that they should log with the NGS when they have made a great find?

     

    If someone wants to just game with this, no problem, I have never ever told anyone that they _should_ log a find with the NGS ever. That is up to them. I am very happy to help them understand how to do this should they want to. Even the NGS likes having these Markers recovered. It is helpful to them and perhaps some recoveries can improve the database. They think it is helpful to them. I advocate that it is great if you want to, but it makes no difference to me if you choose not to. I don't think anyone should make work out of fun if they think that is what it would be. I also think that those who would be opposed, and feel it is work are in error to think that other people may want to and think of it as fun. To each their own. We can walk down both roads here and both roads can lead us home. All good.

     

    >Logging with the NGS sounds like it is something special we should do. But just remember this, We have found benchmarks that were log (on the NGS) as Not found & Destroyed and they showed signs of recent use! It appears as though local surveyors knew where these marks were without using the NGS database. Logging with the NGS seems to lose some of it importance at that point.

     

    That may seem so, but there is more to it than you think. As I said, what you should do is not up to me. There are a lot of bad recoveries in the Database. The USPSQD, Power Squadron visit their website, is just a Volunteer organization that primarily teaches Boating Safety. They recover NGS stations as a public service just as Geocachers can. They are just folks, not pros, and they are obviously not perfect. But make no mistake, you are not dealing with professional anybody when you see their recoveries, they are just volunteers like we are. There is a great reason why you have a lot of not founds and destroyeds, I feel that should be a sufficient reason to do better when I can. As a Surveyor, Yes I know where a number of these are and no I have not recovered them. Many have not needed a recovery, the description and data I have on file for them is still adequate. I have plenty to do in my day, but when I find them to not be adequate or changed, you bet I report them. I also use a number of stations that were set be State DOT, Counties and Cities. I do not use Geodetic markers unless the one I am using is the handiest one to use. I even have used NGS stations and City Stations all in one Survey. They are a resource. They are all important to us, and we do verify that the data is current. On the NGS I get free Data just like you, Updated to NAD 83 or NAVD 88, to the order of accuracy the station has, I use it, you bet. It is cool that a monument that was put in in 1907 can have Data assigned to it that can be that up to date. If a Surveyor is not recovering them, well they may not need a recovery, or may be beyond the scope of the billable work at hand. Sometimes I am the Surveyor using a Station recovered by a Geocacher. One that was once lost too. To those folks who helped make my Job easier, Thanks. To those who just want to play, I think that is great. I play too.

     

    >If you want to log with the NGS please do so, just don't expect everyone else to get excited over all that extra paper-pushing. We're here on Geocaching to get out and "find" things, be it caches or benchmarks and have fun in the process. It really doesn't matter to me if someone else logs a benchmark incorrectly here on Geocaching.

     

    As I said John, You have your way of playing the game, I think that is great the way you choose to, but others play differently than you. That is also a good use of the game. I think it serves everyone well to talk about it all. All the different ways we each choose to Play. I want to make it very clear to you that I have not advocated that anyone should do this my way. I have never really stated My way. I just contribute to the forums as anyone else, I try to help out. I have made comments that will lead some to believe that I feel some methods of recovery lack integrity, and that was what I wanted readers to think. I was hoping to persuade some readers to feel that integrity is important to the game. Just my opinion. I made sure it was an opinion, not a rule or fact. I am quite careful to cite my facts. I think we all have something to add and it is all lifted up and made better through the community in all levels. We all come away as better players on every level. As I said, I do not and never have thought that anyone _should_ push extra paper. I have no expectation and never have, nor should I expect that everyone wants to play the Benchmark game the way you feel is best. But I am more than happy to help when someone wants to take the game to that or any level. _Their Choice_ There are no expectations here beyond what people place upon themselves. I personally choose to try to maintain the NGS data and I try to keep the integrity of their data as high as I can. I feel If I can improve on it, then all the better, but that is just my choice. If others like the same idea as the one I use to guide my actions then they are welcome to use them as they wish. If it does not matter to you, great, then you will not be offended when others do want to carry the recovery further than you personally feel is best for you.

     

    >If you could get 75% of the benchies to log with the NGS, considering all the "mislogged" marks on Geocaching, would Geocaching become another "Power Squadron"?

     

    If 75% would, fine, but it is not realistic to even think it. Even if they did The NGS has Rules for Station Mark recovery. It is incumbent upon all recoveries to NGS to follow their rules. All they ask is for one recovery per station per year. If all you feel you can say is "recovered", then that is considered a competent filing. At least we would know it has or has not been seen lately. If we here in the forum can help the people who care, then those who volunteer to do so will, those who choose not to, wont. Those who don't want to recover anything to the NGS are free to Crow about FTF's and quantities, or the scenic beauty of some of the places this game took them to, and that is great too. What is to say that some of the Geocaching recoveries are no better than those of the Power Squadron? We all get the right and wrong. All I can do is the best I can do, and hope others will too.

     

    I still contend all is well and working just fine. It isn't broken, doesn't need fixed and we are all being served well. There are no Bench Mark Police on GC.com, but there are guidelines. Thanks for raising those points John, you made some good ones.

     

    Rob

  12. Things are really fine here, really they are. Forums are for discussing things and this is what we use it for. There are many topics here, some light and fun, some competitive, some technical, some are dedicated to crowing. Just like the several forums dedicated to Geocaching. I said it so clearly a few posts back, it is serving us all quite well on all levels.

     

    I would like to remind those who may not be aware, many are aware as well as many are not, The National Geodetic Survey has created a special filing for Geocachers who wish to recover benchmarks to them. It is GEOCAC. Yup, you can take credit at the NGS if you like. Your initials will be on record forever. Any geocacher can report recoveries. At the top of the Bench Mark Forum there are several pinned topics that highlight this. The NGS is happy to have the help. These monuments are not toys. They measure the shape of the US, it is important that we realize that if we go this route, we should try to maintain their integrity as we seek to recover them, if we choose to report to the NGS. It would seem a shame to make work for our friends at the NGS cleaning up messes that happen, where is the help to them in that? So in discussing and figuring it out here in the forum is a good thing. We have found errors and collectively helped to sort them out and solve them. It is a very high use of the Forum here. And there is plenty room here for more topics. No Harm, No Foul. If we move this resource of people off to a corner where pros can be pros, then how would that serve the forum? How would that serve the people who have questions? Further, the same pros or accomplished Bench Mark Hunters like hunting in the dark and coming up with song titles for bench mark names they recover. How cool is that? :-) There are no elitists here.

     

    Let me make this distinction. On GC this _is_ a game. If you take it to the next level you can treat it as a game or hobby but the recoveries to the NGS are to their requirements and they do have a different way of seeing "finds" than GC does. This is why some of us here in the forum have volunteered to discuss this and be helpful. It isn't so much about rules and enforcement as it is how to do it properly and how to differentiate between the different systems of recovery. I think most would agree that driving past the Space Needle on an interstate 3/4ths of a mile away is not an appropriate use of the game, let alone taking that any further. I mean if a cacher has to find a cache to sign the log then it seems appropriate to stand on the grounds of Seattle Center and near the needle to recover it. You will read a recovery at the Needles PID here on GC.com that shows some outrageously silly recoveries. Here in the Forum there are Hunters who do not report any recoveries to the NGS and they are still a huge help to all and eager to help any way they can. There is no training officially laying around out there for the Layman to know all this but there are helpful people volunteering. Sometimes we even see several of us who come from Survey backgrounds having different things we add. We all share and learn. What better use of a Forum? A public meeting place for discussion. I see that as something that does not need fixed or changed. There have been some wonderful discussions here on technicality and history, sometimes both. I look forward to reading about Railroads, Airline Towers, State Lines, Radio towers that move and change and Alaskan Highways. we are exposed to things that we get to learn more about and it is a good time. I have a sense others enjoy it too. Those who participated made them great; those who refrained can claim no credit. And if nothing else there are other topics to click on.

     

    Like I said before there are many levels within any hobby, you can have the toy train or a scale model scenic railroad, and all in one hobby. This is no different here. Further I have not read where the Bench Mark hobbyists are over in the geocaching forum posting messages that seem to say that they take their hobby a bit too seriously. :-) Of course I am sure all is harmony there like here. Forums are like TV programming; we don't have to subscribe if we don't like the topic.

     

    Bottom line, I see a ton of helpful people having a great time. This forum actually works better and smoother than most I have ever seen. There are some really great folks here. I think nothing is broken. No need to move or modify a thing. One Forum, Many Topics. Let's not fix it shall we? I would not change a thing. I am with GEO, This one is working fine for me. :-)

     

    Rob

  13. Leprechauns,

     

    Over time I have seen you post in here with the premise of reminding us that you feel anyone who would subject themselves to scrutiny or such rules must be nuts... Well, To each their own, I guess all I can say to you is that I have taken note of your feelings. Message recieved, but it isn't how I feel. It does not persuade me to change my feelings towards the way I follow my hobbies. There are people in the world who are Super Nascar Fans, Super Football Fans, Super Baseball Fans. People who can't stop riding their bicycle, or shopping, or collecting. Folks who have collected every beanie baby or barbie known to civilization. There are people out there who have to have TV shows come reorganize their lives and homes. Then there are those who take a more relaxed approach as well. Even here in the benchmark forum there are people who use the latitude they have to follow the hobby in the way that makes them happiest. I think that is great. I think everyone follows the path they like the best and that is how it works best. Some like competition, some like hunting, some like that they can publicly volunteer to contribute to a civic purpose while they find these and report their current status to the government. I know of several people here in this forum who work in the Survey field who hunt them, and I also know of Surveyors who strictly Geocache and never recover one Bench Mark. Different strokes, and it is all fine.

     

    That said, Happy Benchmarking, if you like, that is. I will still be happy to talk technical with anyone who has a question and wants to follow this craft to the level of recovering stations as accurately as the NGS standards are for so doing. But hey, if you just want to find a few and not log them that's all good too. I certainly would never advocate that anyone do anything they wouldn't enjoy doing. The deal really comes down to having fun at whatever level and I sense that most people are. Thats all :-) Happy geocaching!

     

    Rob

  14. Gonzo,

     

    I like the idea of what you want to do. I enjoy the history of these things and since the Stations in your area were set by the CGS as a part of a project by the US Army, through Canada for the ALCAN Highway during World War II, and it is a history we share. I have read and seen movies of the history, and I have met a few men who worked on the ALCAN. It was as frontier as you can imagine. When you think about how difficult the terrain was and what the tools were like in that era it is a simply amazing feat of engineering given the challenging timeline they had. It was War, and the War was near Alaska in many ways.

     

    You have done a good bit of foot work. There may be more to these monuments in Canada along the Highway than is easy to know using the tools we generally have available. I do not have the right to volunteer services that are not mine to offer but I have an idea. There is a member of the forum here who posts from time to time. He has access to data that is not generally available to most as he is the Chief Geodetic Surveyor of the National Geodetic Survey. His name is DaveD here on the forum.

     

    It is an odd request and not really in the current NGS mission, but perhaps Dave may know if there is any way of accessing the old obsolete datasheets to these Stations so that perhaps you could recover them for historical purposes. We are making a big event here in the states over the 200 year anniversary of Lewis and Clark. The ALCAN has historic importance too. It is possible that the NGS may still have the files archived. Dave? if your are listening, Can you shed a little light on these CGS Stations in the Yukon Territories along the Alaskan Highway? Thanks in advance Dave,

     

    Good Luck in the YT,

     

    Rob

  15. Leprechauns,

     

    It is not that we seek to dissect a find, But Bench Mark hunting can be taken a step farther than simple gaming. The NGS will accept a recovery from a Geocacher. These Survey markers are very important items and they each are linked to data that surveyors and other agencies of all types. They are not Tupperware or a logbook, and I do not say that to belittle anything. It is a good thing to find them, but in finding them, sometimes problems are found along with them. Sometimes we as the finder can improve what we find. That is the hope the National Geodetic Survey hopes from our work as well. They are interested in our finds. We game, and at the same time we can update and improve a National Database. The important thing is that the benchmarks as geocaching refers to them were set by an agency of the US Government and they have a methodology for how they would like to treat them. In the same interest a Geocacher would want to play by the rules of a cache, many of us feel that the nature of the engineering and surveying fields should be honored and observed in respect to the recovery of these objects, as in their essence, they are the basis for all infrastructure and mapping in the US. These objects are the spatial references. They are why airplanes find airports in the dark and why we know where we are on a map, and they are so many other things as well.

     

    All this can be very challenging. I suspect the people who are dedicated to hunting these like challenges like this. Different strokes for different folks. I sense most of us in this forum also see it as a great opportunity as well. But it is science, and we try to pay attention to what improves it. Carelessness in finding and reporting can only introduce error to a database and that would never be a desired effect.

     

    To be honest I don't know if it would be fair to claim that I found a geocache without leaving my desk here, and I am not sure it would be fair for me to claim I recovered the Washington Monument just because I plan to fly to DC next week. (and I am not planning) Certainly shooting photos of the Space Needle in Seattle from a .7 of a mile east on I-5 counts as a find yes? Therefore since since I live in Seattle I can claim all geocaches within the city proper found by me simply because i live here. Or gosh I could have been meaning to go to Portland Oregon soon so what the heck, I claim some of Portland's Caches too. No, that is no way to play. I think we can and should take more care than that. and many of us do.

     

    More than calling anyone out, we are a helpful bunch, we are willing to help anyone figure out a poser, and if you spend a little time reading here I am sure you will find a pretty cool and fair minded group who will roll up their sleeves and research hard to bring the facts out on anything. In my mind it makes for dadgum good reading too!

     

    I would like to invite you to hunt a Bench Mark, if you have a problem, bring it on in and you might be surprised how much and how many you may have helping you and having fun. If it really isn't for you then that is fine too. There is no hunter in this forum that I have ever seen that is harder on anyone than they are on themselves. It is just the kind of integrity they have, and for my money, I enjoy that side of them a lot.

  16. Geo,

     

    I'll bite that the elevation is off, typo wise as that is somewhat rocky mountain high, but it is a Bench Mark and therefore is horizontally scaled. It was never surveyed to be horizontally accurate, so your GPSR reading in the recovery notes should suffice to help future searchers find that. Congrats on finding it. It appears you once visited and did not find.

     

    Just as a note to others who hunt that may not realize. Feel free to pull the original datasheet from the link on the GC page or the NGS, it will tell you a lot about the Station. Generally speaking, if the NAD 83 Coordinate is scaled, then it is a Bench Mark, a Station for elevation. If the NAVD 88 coordinate is Scaled then it is a Triangulation Station. The Triangulation Station's Coordinates should walk you and your GPS right to it, whereas the Bench Mark is likely off by a bit. Sometimes trying to find a Bench when the locale around it has changed is like winning a Yo bet on a craps table. Sometimes it is seven out, line away.

     

    The truest test is to use the description, and verify it as a guide to find the Station, and see if it passes the test. Then update that if need be.

     

    Again, Cool Beans on the find Geo!

     

    Rob

  17. This is probably just silly, but if there are any here who would like to own something that the CGS used on those tripods back in the day, then head to ebay and have a look at this.

     

    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...3843048674&rd=1

     

    The Wild T-3 Theodolite. These were used very extensively in geodetic surveying work for a good many years.

     

    That theodolite, if once owned by the NGS, is likely no stranger to a wooden stand... It is certainly a sister to many who were.

     

    Rob

  18. GH and all,

     

    For Survey Purposes, You can take the Space Needle's Elevation as a good EL. There was at one time a Bench Mark Disc in a Concrete Stairway, SY0362 Century 21, which is since gone, (not found) having been removed in a previous remodel. Station Century 21's Elevation was determined from a few other Bench Mark Stations near the Needle and was verified to Second Order Vertical accuracy. the overall length of the Needle was taken from the Architectural Plans From the Base Line and added to Station Century 21's elevation.

     

    On the Architectural Plans there are often a number of lines, labeled such as the Base Line, A Line, B Line etc, which are locations where Scaled measurements (architect's scale) are to be taken from the plans and made in full scale on the building as things are being built, both from the Horizontal and Vertical. A number of these lines are on plans and they are located for the builders in the Building by Surveyors as the building is constructed so the building trades can use these locations to take and make measurements from. For instance a Wall, a drain pipe or an electrical conduit may be located a specific distance from the B Line or any number of these said hypothetical lines depending on where you are working in a building.

     

    Anyhow, The base line was a Hypothetical place located on a plan but was then determined at what elevation it was actually built at. Things can be built both above and below this line. Then the plan height of the needle was added to this elevation and a direct measurement of the spire added to the top of the needle was calculated for the overall height of the Space Needle and added to that BM at the base of the needle. The Space Needles elevation is 744 feet VERTCON, Third Order Accurate Horizontally. This was determined during the 1963 monumentation of the Needle as a Bench Mark and Triangulated Landmark. The 1973 recovery does state an overall length of the needle in the recovery narrative, but it is not when the Elevation (above Mean Sea Level, as determined by Geoid Height) was determined and I would not concern myself with that number. That recoverer could be quoting marketing literature for all we know, and could be responsible for quoting it wrong. Though there have been remodeling and updates done to the Needle over the years, the appearance of the needle is very particular. The spire on there is the same spire. Nothing has changed up top other than the Paint Job. The Geodetic Elevation is good for NGS purposes no matter what the Space Needle marketing Department wants to print in it's literature. More Importantly, the Space needle has not moved laterally since it was built. I would use it for triangulation purposes and be fine in so doing even if the spire were a foot shorter even though it is not.

     

    For the would be collectors of this Station as a notch in your belt, I would just ask that you physically go to the needle, stand under it and look up, Photograph it from very close up before you claim a find. Better yet, go to the top and Photograph that view, it is quite spectacular. On a sunny day, even better. It is a $12 ride to the top. Don't claim it because you are planning a trip or coming to Seattle, Don't claim it because you drove through Seattle on the Interstate, a mile east of the Needle. Just visit the Needle. Otherwise the recovery is worth no more than claiming all the NGS stations at any given Airport by default of having flown into there and never setting foot on the flight-line.

     

    Rob

  19. Well, It is true that some wood is better than others but here in the Northwest, the ever wet weather would have reduced the wood to a pile of rot years ago. As an artifact, it is cool to see those old tripods still in some semblance of condition but sad to think they left it there as garbage.

     

    I would just have to speculate about all the wires you find at some sites, but the batteries that powered the lights used for night survey work were often on the ground and wires ran up to the light unit. Perhaps the wires you find were used for that.

     

    In retrospect, I would have not thought you would find a tripod, let alone wires... It would be nice to think they had cleaned up the mess they made, but that was another time, a different era.

     

    Rob

  20. What that wooden object is, and was used for, is a wooden tripod for either making observations with a theodolite, or holding up the heliotrope "light" when observations were being made. There is always an instrument height, "height of the light" for all observations, Night or Day on both ends of an observation whether they mention in the description that there was or not. We even use that term loosely in the field today, whether we are using an actual light or most usually just a reflector. The distance from the center of the optical instrument or light, to the top of the Station Disc is the Height being referred to. You did find something special that was used at that location by the surveyors and abandoned when they were done using it.

     

    See Here,

     

    Also see Here.

     

    Rob

  21. This is a little off topic but mostly on. Maybe it will help you to find what you are looking for, until Dave D can find you an answer.

     

    Through reading the history of the Coast Survey, I learned that here in the State of Washington the initial survey first passed through this area in 1854. To find the stations they set, if still extant, and they are, I looked at the NGS Datasheet Website to find them. I used the county search, using only coastal counties, then I narrowed my search to First Order Horizontal accuracy marks to weed out a lot of what I did not want to see, then I started looking Pid by Pid to see the date of monumentation. I repeated the process to look at Second Order Stations as well. I found 3 Stations which started out in 1854 as Drill Holes that were 1/2 inch wide, 2 inches deep, later re-drilled to fit brass discs in the early 1900's. They are all in remote coastal locations and are still there from visits in recent years. I have read of some in the mainland too but development has destroyed them all. This method is not super fast but it was a fun search for me. I have a few counties to read up on yet if I want to finish this work, but I did find some of what I was looking for. Here is a story about one of them, It is an interesting history when you make the connections.

     

    If you like, you can read the official NOAA History of the CGS and it's initial work in Texas Here. Whether any of the marks set from that time are still in existence is hard to say. I do know that the most work and best selection of locations is used for first order Stations in that day and so the likelihood in searching for those Stations and finding them still safe and sound is highest.

  22. Power Companies are Strange when it comes to procedures, that is for sure. Sometimes they will never renumber, sometimes they will replace a pole and renumber or not. You just never know. What I want to say from the field, and it is a common thread from most of us who work in the field here is that just when you think there is a hard and fast rule you can sort of trust, something will come along to shatter that rule.

     

    Spoo, You are correct in your neck of the woods, and practices vary in all necks of the woods, Some utilities cannot make up their minds as to what the practices are. I have about four different utilities in this area who's practices are all over the map. I know you are a seasoned hunter but for the sake of those who are not, I think you will agree we read about two posts a week about PID's that are said to be way off coordinates and when I look, I find they are a Scaled Bench Mark station and that is why the coordinates are way off. For the benefits of the many who read and never post here, I thought I would bring that up for their benefit. This is how we can know more that just what is first presented on the GC website.

     

    mloser, I was not correcting you, you can legitimately call it macadam, but many people, in a national sense will not know what you are referring to. It is not better to call it asphalt, just more widely known by everyone. It was at one time in the early days referred to as macadam. That usage has fallen out of use even in the asphalt paving industry. I just pointed it out as many people would not have realized they are the same thing. More people read this forum than we think :-)

     

    Triangulation Stations can be off. It happens, but not as routinely off horizontally as Bench marks are. I have a third class Triangulation station I am hunting that is a real poser. I know where it should be based on the description, and my telephone poles have moved. Instead of a tree I have a Man Hole cover as a reference point that has been paved over. But I can see where it is. My Station is in a one time parking strip along side a street that is now covered with a 13 foot high dense blackberry bush. I hacked in and did not find. There is no reason it should not be there despite the changes. I am on the right street, right intersection, right location...

     

    On the interesting side of things this Station has a weirdness. my intersecting streets have an east-west street, and a southeast-northwest street. Based on the description the Station _should_ be West Northwest of the sewer man hole in the named intersection at a stated distance. Did not find, and so far as the reference marks are DNF too. I can live with that, but the Station Coordinates should be good. Most typo errors on a triangulation Station will run you either North, South, East, or West of the correct location. A mistake is either in the Latitude or the Longitude, rarely both and if both it would be wildly off. In this case the Station Coordinates lead to a place there is no intersection at all, not within anywhere near the stated lengths in the description, and this is along the southeast- northwest running street 500+ yards southeast of the described location. Oh and the distance from the centerline of road is the same for the described location. This would require a fluke or something to properly parallel the street in the manner this has, but I have not yet hacked into the brush. This means the Lat and Long were both off but still follow the angle of the Street? Too weird. To add, the changes in the area, and growth of trees and foliage around this Station in either of It's possible location would require a Bilby Tower of 75+ feet to do much with it optically.

     

    I think the Station Descriptions that I find most troublesome are from any era, the ones where there are 2 reference marks set, like in curbs where they are easy to find, but they use everything under the sun to describe the Station location, and do not use the RM's. If they would add that the Station is 54 feet NW of RM 1 and 37 feet NE of RM 2 then you could find it in a second with 2 tape measures. But that part is often omitted. However, if I go (about) 229 paces to the left of the centerline of a sidewalk that is in line with a jog in a road and near a tree whose diameter is about 22 inches in circumference... :-) I too, feel your pain.

     

    Rob

  23. mloser,

     

    It is common for poles to be replaced for whatever reason. If there was a road widening, then there would likely be new poles and the new poles will have new numbers. This is common Power Co Practice, NOT a bad practice of the setter of the Monument. Nothing is forever, and we have no right to expect that, and nor does the NGS, when we leave the shop in my profession we go to the field to see what is there. No expectations. I would go see if that tree is still there and go from there. Oh, and for those who do not know what Macadam is, It is a very old fashioned word for Asphalt Pavement. The asphalt industry stopped using the term over 50 years ago.

     

    Spoo, One trick to all this is go to the NGS site and pull the real data sheet and see what you are really looking for. if it is a Bench Mark. I mean in the strict term, a Bench Mark, an Elevation Station. If it is as such the coordinates will be often scaled and you cannot expect to find it near the printed coordinates. It it is a Triangulation Station, the coordinates should be closer a few inches, which is closer than a consumer GPS can do.

     

    The real deal is the real Datasheet. I would not fool with the GC.com description. Just use them to find marks that are in their database, then go get the real info. There is so much more to know if you use the latest NGS Data. Knowing if a mark is horizontally scaled is going to make a difference on finding a hard one.

     

    Rob

×
×
  • Create New...