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How to slant a BM report?


patw

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This topic really involves what attitude we are to take in bench mark hunting and reporting. Do we continue in a geocaching vein? That is, do we carefully avoid spoilers in our reports so the next seeker can have the same experience? Or do we attempt to assist others, particularly local surveyors, in making the find easier, say with an area photo with an arrow pointing to the bench mark?

I would suggest that the least we should do is:

a. Correct or refine the description, especially if it involves updating destroyed landmarks or a suspected destroyed bench mark which we only report as NOT FOUND.

b. Refine the coordinates of scaled locations to move the hunt closer to a gps experience a la geocaching. This would be especially appropriate if our gps includes averaging, WAAS, and/or EPE reporting. A simple photo of the gps beside or on the bench mark would suffice. Surely we can improve on the plus or minus 600 foot accuracy of a scaled citation. The big boys properly suggest that following the description is almost always simpler than relying on our gps. But that only refers to scaled coordinates. For adjusted coordinates, I always give precedence to the gps hunt.

c. Include some details of the personal experience of finding the bench mark. For most of my early finds, I simply followed the Power Squadron's form of "Recovered in good condition as described." But this now feels just a bit too officious for our geocaching community. I'm now favoring a geocaching type report in an attempt to share some of the experience with others in the community -- repeat -- the community.

. . . . patrick & shirley

 

patrick & shirley

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Jeremy's position in this thread is that we should post as much as we feel like, there are no spoilers, because benchmarks are not caches.

 

Since benchmarks aren't supposed to be hidden in the first place, please feel free to give a detailed, accurate description of the location.

 

ntga_button.gifweb-lingbutton.gif

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The better the description the more useful it is. There will always be plenty of remote markers for others to pursue if they feel like a recently recovered marker is not worth visiting. In fact, it probably wont be long before it will be difficult to avoid repeats without going some distance.

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I agree with surveytech and webling. As an avid benchmark hunter i enjoy the hunt but dome of the desriptions written almost 55 years ago are not alot of help today. Some are right on with lat/long coordinates and some are not. Those that are not can usually be found with the help of the desriptions. Updated desriptions or accurate logging should be encouraged.

 

"Not only is the universe stranger than we imagine, it is stranger than we can imagine."

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patw -

 

When I started benchmarking, I saw that the fun I was having would be a non-renewable resource unless I was very careful not to spoil it for others. If I took 'spoiler pictures', then there'd be no challenge whatsoever for the next person. The same applies to improving location instructions.

 

I commented on this here in the forums, but I soon learned that almost no other benchmarkers were concerned about this. The method of operations was to 'spoil' the find totally in the attempt to make the benchmark much more findable than the original description by improving upon it and taking location pictures. So I gave up. I do the same as everyone else. I take a disk pic and a location pic and post them.

 

There's sort of a dichotomy here. Is benchmark hunting "just a game" or is it "serious business"? I don't know, really. I do know that for me, it's a great game to find a benchmark if you're the first geocacher to get to the benchmark. While reporting, though, I don't treat it as a game, and I try to be as strict in my interpretation as the NGS would want.

 

If I don't see the benchmark that's supposed to be there, I count it as not-found, etc. If there's some kind of mark on the roof of a building, I don't count it as found, unless I can go up there and see it with my own eyes. Being near the mark or seeing where it used to be is not a find.

 

If it's truly "just a game", and not serious business, then we should not make the mark extremely findable, and instead make sure to let others work through the 'surveyspeak', the changed landmarks, the 'scaley' coordinates, etc. themselves.

 

If, on the other hand, it isn't "just a game" and we are essentially acting as assistants to surveyors and the NGS, then we should report as accurately as the NGS and surveyors would have us do, and not report like it was a game.

 

What about being the second to get to a benchmark? Well, I figure I could print out other people's location pictures for 80 benchmarks, load up the locations in my gps and run around and double my find count in a day. Hardly any challenge or fun to find any of them.

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I say don't worry about spoilers...I'm geoclipping the pages to my PDA, and I pretty much ignore any logs unless I get to a point where I want a hint. Sometimes it's enough help to know that someone did indeed find it, and on rare occasions I'll rely upon specific information in the other logs. But it's easy to ignore in any case so I don't think spoiler-type information would get in anyone's way without their decision to look at it.

 

Pictures are in the same vein. They should ideally show clearly the location of the BM in the context of surroundings. But I won't look at those until I've either found it or I've given up on finding it on my own.

 

Of course, that's just my opinion...there's definetly other ways to look at the matter.

 

Max

Often wrong but seldom in doubt

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Knowing that most RLS's (registered land surveyors) don't log on to www.geocaching.com to look at pictures of a mark to help them find it, by simply tying a piece of survey tape above the ground mark or staking it, you can save a surveyor much time. Of course, there will be arguments about littering and aesthetics, but after all, these marks were not set for your enjoyment, rather for control of survey measurements nationwide. Furthermore, these handheld GPSs are not accurate enough to update NGS records with. If you want an accurate reading you'll have to run a level circut from a first-order mark (often a mile or more away), set 3 TBMs for Z, then get your X,Y with a RTK GPS (3mm accuracy) or a Total Station. I know for a fact that my crews and most respectable RLS's don't use the GPS coord's from the NGS (they are generally adjusted through modelling), rather they use the State Plane coords or the UTM.

 

For what it's worth, have fun.

BH

 

"In surveying, you're doing your job well to end up at the POB, most others would be considered lost."

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They have the Better GPSr than we do why do they need our help to find them? What abou the RLS's that don't use the Benchmarks or Triangulation Station's? Refering to State Plane Coordinates these are a X,Y,Z transformations of a 90 degree starting point,if you look at the original maps and plats this 90 degrees is not the way it turned out with the Clark Spheroid,which was used.We could go on forever about what was changed,Before recently no one had a way to check this out,The Knowledge was with those who went to school for many years,now we have the GPSr to do those Long base lines and deflections of the Vertical over long distances. icon_wink.gif

 

When all else fails Geotry again.

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True, these points were not set for enjoyment, but the hobby has caught the interest of a number of people, and hopefully, through enjoyment they will learn to respect, appreciate and perhaps even help preserve what remains of the original control network by passing the knowledge they come across here along to others. All the technical info is really irrelevant, since the purpose of improving the descriptions on this site is to advise other geocachers and any benefit to surveyors is a mere by product. The chasm between handheld GPS and survey grade GPS has been explained here many times and I dont think anyone here has any illusions that just because they have learned how to find markers means they are ready to go out and start surveying.

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I hunt benchmarks, and I make an effort to report in a more formal style, but I also have no illusions about the accuracy of my measurements. Mainly, I hunt them for fun. The other half of the team (my wife, Sharon) has less-than-no interest in benchmarks, so I can chase them on my own. But I would be very surprised if any surveyors use this site for info on them. At best, I would think that our greatest service would be if we could prove that a BM does not exist within a good-sized radius (1/10 mile?) of where one was reported 30 years ago.

 

I would venture to guess that the vast majority of geocachers think that our handheld "toys" are precisely accurate. I have taken some pains to explain to folks that this is not true, but many of them refuse to listen. Take a look at my log notes for our cache "Horse Opera" (use ZIP 93010; it should be first) for some interesting comments on this. I tend to think that if we find a cache at exactly the coordinates posted, either the planter made a mistake, or else they and/or we were incredibly lucky! icon_redface.gif

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I agree with you in general, except that I think its best to set out to prove, rather than disprove, the existence of any point. If the area is so different that the description is worthless, then no absolute conclusion can be made, GPS or no GPS, although it may be hard to imagine how the marker could have survived, some have in such cases. Im sure a lot of people do have misconceptions about the capabilities and eccentricities of GPS, but thats all just part of the learning experience, and no harm is done as long as no one gets the idea that knowing a little bit about markers and coordinates makes one a surveyor. I have been in the surveying industry 20 years as a technician and I am not qualified to call myself a land surveyor. Most people do not realize that the biggest part of becoming a land surveyor is not merely knowledge of the mathematics but a thorough and complete knowledge of the law. Anyone can punch buttons and generate numbers, being a successful surveyor requires a far rarer skill, superior judgement.

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I was a measurement tech for many years,I am in no way saying that the conclusions that I draw from my experience make me a licensed land surveyor,but analysis from data sets is always in the eyes of those with the data.To go into the technical aspects of the way that the surveying is to be performed is found in the BLM Manual Public Lands Surveys.Many years of study are required to understand the concepts involved in this.If you Start at the Louisiana Purchase http://www.arkansasstateparks.com/parks/default.asp?parks=Louisiana+Purchase Township 1 Range 1 and 6 miles by 6 miles, do the math to say Range 27 should be 156 miles,that is mathmaticaly and by the book. What if it turned out to be way off?

 

When all else fails Geotry again.

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Some remarks on the last few posts:

 

Staking. There has been a poll/topic on this subject before; check here for a review. (71% said not to do it.)

 

Prove it isn't there. You can't. I've seen a benchmark (BM) the description said was on the surface but was buried a foot deep (dug up by some surveyor). Our GPSs (I call mine my "jeeps".) have an accuracy of a few feet. Good luck digging up a 15-foot diameter circle a foot deep without getting into big trouble! This applies to Adjusted horiz. coord. BMs. For Scaled ones, forget proving they don't exist using coordinates no matter what kind of GPS you have. From the NGS perspective, the only way to prove a BM is gone is to see the BM (catch 22!) out of its position.

 

Helping surveyors find it. The coordinates generated by our little GPSs are junk compared to those generated by the millimeter-accuracy ones surveyors use, as has been stated on this forum 50 times. However, for SCALED BMs, listing coordinates here in geocaching.com would be of help (do they want it?) to other benchmark hunters among us. These days, even some real surveyors might carry along a toy GPS like we use and coordinates could help them just to find a Scaled horiz. coordinate BM. Still, much more important than posting our coordinates for BMs, is to post updated verbal finding instructions if they've changed significantly. Do professional surveyors refer to our benchmark pages? Very unlikely, but it's still fun to imagine that they do. icon_wink.gif

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I do post a location shot for every benchmark. When I am looking through the gallery I find these pictures to be the most interesting. I probably will not visit this benchmark. But those shots are useful finding benchmarks placed the same way. I guess for now I will show a shot of the general location.

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Whether or not you decide to provide a brief or detailed description would be completely up to you. The same goes for the pictures. I think that from a caching standpoint, which is what we're doing on the Geocaching.com site, the pictures are only to prove that you were there, as there is not a logbook to sign.

 

When I'm caching, I note on the cache page about my experience hunting for the cache and try not to give any spoilers. When I'm benchmarking, I tend to fall back on my training and accurately describe (sometimes over-describe) what I find or don't find, i.e. 'found as described and in ______ condition, blah blah blah." Like Black Dog Trackers said earlier, "updated verbal finding instructions" are more important to a surveyor than any GPS coordinates we may take, although there are probably very few surveyors who use this site strictly for benchmark information purposes. I have used it for that purpose a few times, but I usually get my needed info elsewhere.

 

I do take new coordinates on the benchmarks I find, and I do report the length of time I occupied the mark and the number of satellites I had visible in my log on the page. I DO realize that those coordinates are nearly worthless to a surveyor who needs to measure to that point, but it may help him or her find that point. Every surveyor I know has at least one or two (usually many) stories where they were looking for a benchmark or survey point and were unable to find it until a nearby resident or landowner showed them where "that survey marker thing" was. I view my benchmark find logs like I was that resident landowner - maybe not survey-grade info, but definately helpful. I figure if someone wants to go look for the benchmarks without the spoilers, don't read the logs. (Of course, in my area, I seem to be the only person actively searching for benchmarks and logging them here, so it's fairly irrelevant.)

 

What I find when I'm out benchmarking I only post here on the benchmarking pages. (Until last week, I had never found a benchmark that I felt warranted a report to the NGS. This one probably does: GU3441) Mostly because I was not able to give an adequate search to an area to to prove or disprove it's location and/or condition. (Truth be told: Sometimes, I don't want to dig a 15 foot diameter hole a foot deep if I didn't have to.)

 

Ultimately, how you decide to search for a benchmark and what you decide to post on this site are up to you. Just have fun with it whatever you do.

 

Keep on Caching!

- Kewaneh

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We(Susan5515 and DCJ) have been including coordinates and photo's with the logged visit to each benchmark we find....don't know why but did so from the beginning. Most time for the benchmarks we find we are 150 feet off and so the benchmarks are more challenging. If we let the GPS sit for awhile we generally get within 6 feet of the caches. So we believe you should include the information and then if someone wants to go out and find it they hopefully will quickly and then let you know if their coordinates differ from yours. We also noted that our gps readings are 'off' if we lay the gps on the benchmark, so we tend to hold the gps upright let it settle and then lay it down and get the picture. So some of our may be way off and not help the next person anyway. icon_confused.gif

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I checked out some of your benchmark finds and note that the majority (almost all) are SCALED coordinate ones. (Under the coordinates is a line saying "...location is SCALED.") The fact that you're finding so many scaled ones is commendable! They are typically the hardest kind of benchmarks to find!

 

SCALED coordinates are never accurate because they don't need to be because the benchmark is only for establishing an elevation value, and the verbal description is supposed to be enough to find it. Instead of using even a non-surveyor-quality GPS like we geocachers have, the surveyors just plotted the location on a topo map to get coordinates from the map with not much accuracy. Geocachers, however, hide their caches and use a GPS to tell the coordinates of their cache instead of trying to plot it on a map and read the map's coordinates. So the location of geocaches is more like the accuracy of ADJUSTED coordinate BMs.

 

Adding your GPS's coordinates will certainly help in finding the SCALED benchmarks, and you'll notice that your coordinates are usually different from (much more accurate than) the ones in the benchmark page for the SCALED BMs. For the ADJUSTED ones on the other hand, the ones on the benchmark page will be much more accurate than you can get from your GPS, so you need not note them. (Unless you want to demonstrate how inaccurate your GPS is. icon_eek.gif )

 

[This message was edited by Black Dog Trackers on January 29, 2003 at 02:24 PM.]

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I don't update the coordinates for triangulation stations. But I provide my own coordinates for the rest. For most of them the accuracy is improved from hundreds of feet to less than twenty feet.

After reading the comments here I have decided to continue posting pictures as I have been. I am mostly the only person looking for benchmarks in my area. If someone would want to go to a benchmark I have found they don't have to download the location shot. I have only gone to benchmarks that others have found a few times. Three of them were near caches. Two of them were U.S.G.S. disks from the early 1900's.

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I just started Geocaching, and I'm thinking about trying to run down a few Benchmarks in my area, too...especially ones that haven't been located in 40 or more years.

 

The question I have is this: if you find a benchmark where the description reflects a situation that has changed greatly over the years, does it make sense to submit a report to NGS with an updated description of the location? While the coords off our GPSr's aren't sufficiently accurate for their purposes, wouldn't an updated description be valuable?

 

If so, then it seems to me that, if you don't want to post spoilers on the Gecocaching site, you could post your "vanilla" report here, and submit an updated description to NGS.

 

My apologies if I'm all wet.

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I agree with El Oso also. As I have said before, A carefully updated description of the vicinity, whether you actually find the marker or not, is the most beneficial thing one can provide for anyone, surveyors or geocachers, who may follow. In some cases, where the scene has changed drastically and few or no original objects remain, the description may seem to point to the likelyhood of the demise of the marker, and one may even state one's inclination to believe that it is gone, without going so far as to declare it categorically destroyed. Read a number of the better existing NGS descriptions and you will see many good examples of this. If you choose to mention the coordinates you obtain in a recovery note to NGS, it would be prudent and helpful to specifically state that they were derived from a handheld unit to avoid any confusion

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Here's an example of a simple updated decription of one I recovered a few years back.

 

quote:

 

 

The NGS Data SheetSee file dsdata.txt for more information about the datasheet.DATABASE = Sybase ,PROGRAM = datasheet, VERSION = 6.71

1 National Geodetic Survey, Retrieval Date = JANUARY 31, 2003

RL0117 ***********************************************************************

RL0117 DESIGNATION - F 160

RL0117 PID - RL0117

RL0117 STATE/COUNTY- MI/BARAGA

RL0117 USGS QUAD - ALBERTA (1985)

RL0117

RL0117 *CURRENT SURVEY CONTROL

RL0117 ___________________________________________________________________

RL0117* NAD 83(1986)- 46 44 46. (N) 088 25 54. (W) SCALED

RL0117* NAVD 88 - 259.951 (meters) 852.86 (feet) ADJUSTED

RL0117 ___________________________________________________________________

RL0117 GEOID HEIGHT- -34.03 (meters) GEOID99

RL0117 DYNAMIC HT - 259.966 (meters) 852.91 (feet) COMP

RL0117 MODELED GRAV- 980,663.0 (mgal) NAVD 88

RL0117

RL0117 VERT ORDER - SECOND CLASS 0

RL0117

RL0117.The horizontal coordinates were scaled from a topographic map and have

RL0117.an estimated accuracy of +/- 6 seconds.

RL0117

RL0117.The orthometric height was determined by differential leveling

RL0117.and adjusted by the National Geodetic Survey in June 1991.

RL0117

RL0117.The geoid height was determined by GEOID99.

RL0117

RL0117.The dynamic height is computed by dividing the NAVD 88

RL0117.geopotential number by the normal gravity value computed on the

RL0117.Geodetic Reference System of 1980 (GRS 80) ellipsoid at 45

RL0117.degrees latitude (g = 980.6199 gals.).

RL0117

RL0117.The modeled gravity was interpolated from observed gravity values.

RL0117

RL0117; North East Units Estimated Accuracy

RL0117;SPC MI N - 219,140. 7,890,610. MT (+/- 180 meters Scaled)

RL0117

RL0117 SUPERSEDED SURVEY CONTROL

RL0117

RL0117 NGVD 29 - 259.924 (m) 852.77 (f) ADJ UNCH 2 0

RL0117

RL0117.Superseded values are not recommended for survey control.

RL0117.NGS no longer adjusts projects to the NAD 27 or NGVD 29 datums.

RL0117.See file dsdata.txt to determine how the superseded data were derived.

RL0117

RL0117_U.S. NATIONAL GRID SPATIAL ADDRESS: 16TCS906779(NAD 83)

RL0117_MARKER: DB = BENCH MARK DISK

RL0117_SETTING: 7 = SET IN TOP OF CONCRETE MONUMENT

RL0117_STAMPING: F 160 1948

RL0117_STABILITY: C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO

RL0117+STABILITY: SURFACE MOTION

RL0117_SATELLITE: THE SITE LOCATION WAS REPORTED AS SUITABLE FOR

RL0117+SATELLITE: SATELLITE OBSERVATIONS - November 06, 2000

RL0117

RL0117 HISTORY - Date Condition Report By

RL0117 HISTORY - 1948 MONUMENTED CGS

RL0117 HISTORY - 1982 MARK NOT FOUND USGS

RL0117 HISTORY - 19920820 MARK NOT FOUND USPSQD

RL0117 HISTORY - 20001106 GOOD MIDT

RL0117

RL0117 STATION DESCRIPTION

RL0117

RL0117'DESCRIBED BY COAST AND GEODETIC SURVEY 1948

RL0117'1.2 MI E FROM L ANSE.

RL0117'ABOUT 1.25 MILES EAST ALONG U.S. HIGHWAY 41 FROM THE DULUTH,

RL0117'SOUTH SHORE AND ATLANTIC RAILWAY STATION AT L ANSE, AT A CURVE

RL0117'IN THE HIGHWAY WITH TANGENTS WEST AND SOUTHEAST AND THE JUNCTION

RL0117'OF A GRAVEL ROAD EAST, 285 FEET EAST-NORTHEAST OF THE CENTER

RL0117'OF THE JUNCTION, 34 FEET NORTH OF THE CENTER LINE OF THE GRAVEL

RL0117'ROAD EAST, 92 FEET NORTH-NORTHEAST AND ACROSS THE GRAVEL ROAD

RL0117'FROM THE CENTER LINE OF THE HIGHWAY, 63 FEET NORTH AND ACROSS

RL0117'THE GRAVEL ROAD FROM A POWER POLE BETWEEN HIGHWAY AND GRAVEL

RL0117'ROAD, 24 FEET WEST-NORTHWEST OF A TELEPHONE POLE, 2 FEET

RL0117'NORTHEAST OF A WHITE WOODEN WITNESS POST, 2 1/2 FEET ABOVE THE

RL0117'GRAVEL ROAD AND SET IN THE TOP OF A CONCRETE POST PROJECTING

RL0117'4 INCHES.

RL0117

RL0117 STATION RECOVERY (1982)

RL0117

RL0117'RECOVERY NOTE BY US GEOLOGICAL SURVEY 1982

RL0117'MARK NOT FOUND.

RL0117

RL0117 STATION RECOVERY (1992)

RL0117

RL0117'RECOVERY NOTE BY US POWER SQUADRON 1992 (GG)

RL0117'MARK NOT FOUND.

RL0117

RL0117 STATION RECOVERY (2000)

RL0117

RL0117'RECOVERY NOTE BY MICHIGAN DEPARTMENT OF TRANSPORTATION 2000 (MPR)

RL0117'L'ANSE, 0.45 MI EAST ALONG US-41 FROM THE M.D.O.T. SERVICE FACILITY,

RL0117'THENCE 0.175 MI N ALONG DYNAMITE HILL RD, 94 FT S80E OF A CHAIN LINK

RL0117'FENCE CORNER, 92 FT N OF ROAD C/L, 23 FT N60W OF TELEPHONE POLE 50414,

RL0117'IN LINE WITH 4 WOOD POSTS, 1 FT ABOVE GROUND AND 2.5 FT ABOVE THE

RL0117'ROAD, 1 FT N OF A WITNESS POST. PROPERTY OWNER = L'ANSE MANF. CO.

 

*** retrieval complete.

Elapsed Time = 00:00:00

 


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quote:
Originally posted by survey tech:

If you choose to mention the coordinates you obtain in a recovery note to NGS, it would be prudent and helpful to specifically state that they were derived from a handheld unit to avoid any confusion


 

Would there be any point in reporting these? The scaled coordinates are off quite a bit, as we know, but what would NGS do with our new coordinates, given that they are from an untrained user with a handheld device?

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Nothing, they would not use them at all. They will only allow these updates by their own field crews who have the software to make the updates.

 

All you can do it add text.

 

I would recommed you not add your GPS coordinates to any reports to NGS. On this site it OK.

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Thats right, although some here rebeled when I said the same thing several months ago, its best to refrain from sending any recreational coordinates to NGS. They will not supplant the existing professional coordinates as a matter of policy, even though they may be better than the scaled coordinates, as has often been mentioned here. If you list the coordinates within the text of your description your submission may or may not be used, which is what I was referring to above about creating confusion in the datasheets. For those who cannot resist the urge to publish their own personal coordinates, using the handheld disclaimer is a way of preventing any potential confusion as a courtesy to future readers of the datasheets who may eventually be confronted with long descriptions replete with varying coordinates for markers that have been frequently visited by GPS enthusiasts.

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