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Benchmarks Recovered


BillP3rd
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What I've seen and read from the administration around here is their official view on benchmark hunting is that it's only for fun.

 

Adding a link to the NGS for reporting the benchmarks would seem like some sort of commitment, or as if Groundspeak was requesting that we report them. They don't want that and I don't blame them.

 

If we do, and I do, then it's up to us.

 

If I'm some kind of yahoo and fowl things terribly then it's my backside, not theirs.

 

I'm thankful that they have added what they have and supply the data sheets.

 

I also hope the NGS gives credit where credit is due.

 

Thank you Jeremy for the fun and adventure! icon_smile.gif

 

~Honest Value Never Fails~

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What I've seen and read from the administration around here is their official view on benchmark hunting is that it's only for fun.

 

Adding a link to the NGS for reporting the benchmarks would seem like some sort of commitment, or as if Groundspeak was requesting that we report them. They don't want that and I don't blame them.

 

If we do, and I do, then it's up to us.

 

If I'm some kind of yahoo and fowl things terribly then it's my backside, not theirs.

 

I'm thankful that they have added what they have and supply the data sheets.

 

I also hope the NGS gives credit where credit is due.

 

Thank you Jeremy for the fun and adventure! icon_smile.gif

 

~Honest Value Never Fails~

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I don't know if a link indicates a commitmemnt.

There is a link of offroute.com and no one appears to be committed to buying from them.

 

I think that a Groundspeak / NGS arrangement is a pretty workable thing. NGS appears to work well with the PSA, and that is a completely volunteer organization. I am pretty sure that membership in the PSA does not infer a commitment for their members to do recovery.

 

I think it would be pretty cool for Groundspeak to become an "approved agency" so the group could get the credit due. I don't know how many recoveries the PSA has made, but our numbers are really getting up there.

 

I would like to think that NGS is fully aware of out activities and perhaps uses our database, our points their customers to us.

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The term "recovered" indicates that the benchmark you have found has been lost to someone at sometime. When searching for these benchmarks, and sometimes finding others in the process, it's important to remember that the NGS is not the only agency that uses and/or sets benchmarks of one type or another. There are many different agencies that have survey monuments that you may come across. The NGS is one of many. Along with any local surveyor's monuments and local government & State government agency caps you may find when you are out and about, the USGS (United States Geological Survey), the USACE (United States Army Corps of Engineers), the USC&GS (US Coast & Geodetic Survey), the NOAA (National Oceanic and Atmospheric Administration), even the FAA has survey benchmarks that you may physically find, but not find in the NGS database on the Geocaching website. I was on top of Mount Whitney a few years ago and saw at 7 or 8 brass caps. Each from a different agency and with a different elevation! (If I remember right, one of them was even tagged by the National Geographic Society!)

 

As far as reporting it to the NGS: you can if you want to, but they probably won't do anything with the info other than say 'Thanks'. Most of the marks in the NGS database were either set by them, set under thair direction, or set by an NGS approved agency with similar surveying standards. If they are interested in the mark, they would have to send someone out to verify it and survey it to "tie it into" their network.

 

As far as Geospeak or Geocache.com becoming an approved agency... that's not very likely. It is becoming a widely accepted hobby, but it's not a surveying or geospatial agency. The NGS and most other agency benchmarks are set using very strict surveying guidelines and practices, described in the surveying profession as "first class, first order" or "first class, second order", etc. The class and order are a way of determining the precision of the mark or survey. Using a recreational GPS unit as a surveying tool will not produce results that are not even on the scale! Even a WAAS enabled, recreational GPS unit can only give results that are plus or minus 16 feet. That's a 32 foot window. GPS units typically used by surveyors, which cost between $25,000 and $100,000, depending on the type of receiver and antenna, can easily have sub-centimeter accuracy, and it is still possible (for a sloppy surveyor) not to achieve the desired, or required, class and order.

 

Have fun with the benchmarks you find and enjoy the history they represent. If you find one that is not in the NGS or Geocache database, you could do research, beginning with the local agencies, to find out more about it. Someone set it, and if it is still in good condition, someone probably knows about it.

 

Keep on Caching!

- Kewaneh

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quote:
Originally posted by Kewaneh & Shark:

 

As far as Geospeak or Geocache.com becoming an approved agency... that's not very likely.


 

Pish posh. If PSA can do it, so can we. And NGS has on many occasions indicated they can no longer go out and verify if these marks still exist.

 

I'll look into it. Perhaps we can work out a logging function where we can help qualify recovered benchmarks so it will be of some use to the NGS.

 

Jeremy Irish

Groundspeak - The Language of Location

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I think that is the question that would need to be adressed. If I go out with a recreational GPS, tape measure, and find a benchmark as described in the documentation, that information can be provided as a status update indicating to the NGS that the benchmark still exists as described.

 

If I also take yellow crayon, and camera, and take a picture that provides useful information about the condition of the benchmark, that also would be useful information.

 

Including the information about the Lat and Lon of the benchmark, as your gps reports it, allong with the resolution your gps is reporting, would be of less importance to the NGS, because of the problems of accuracy.

 

Of greatest importance that we can provide is an indication of the condition of the benchmark. Does it still exist, or was it removed as part of rebuilding the road it was originally part of? Did the building the benchmark was a part of burn down 10 years ago, and there is now a completely different structure there? Did someone bring along a hacksaw blade, and cut the benchmark off of it's mounting point?

 

I don't know that these are of major concern to the NGS, but I suspect that condition and existance are of more concern to them than the fact that your gps shows the location to be fifty feet from the reported location. Especially if it is located exactly as described in comparison to the reference markers that were described.

 

Then again, I could be wrong.

 

-Rusty

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That someone has gone out a verified that the benchmark exists and that it's description is accurate. The PSA does not use KiloBuck GPS units.

 

In general, any benchmark that does not have an updated description in the last 10 years should have a recovery note. This is essential to groups who use these benchmarks (not just the surveying community).

 

In regards to Horizontal vs. Vertical BMs. While our lowly hand-held GPS units will add little accuracy to a Horz Class A1, our readings are very good for estabilshing the "real" location of Verts. So a hand held GPS reading included on the recovery note of a 30 year old V3 may just make the difference between that mark ever getting used. The inclusion of your GPS readings on a Vert do not "change" that benchmarks co-ords, but they make it a whole lot easier for someone to find it!

 

Also, the routes to the benchmarks are constantly changing. Thus an updated (and correct) description of access will win you many friends on the old stake and chain gang.

 

Lastly, having your initials connected to a physical reference on the planet for all time has a bit of coolness. 100 years from now, some poor survey tech will thank you for your effort and perhaps say "Yeah, Groundspeak, JCA, always gets me to the mark".

 

In my book...we are providing a vary valuable service to the scientific community.

 

And yes, the NGS cares.. as long as we bring a level of professionalism to our recovery reports.

 

Personally Responsible for the Recovery of .00176% of the Benchmark Database!

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This has been an excellent discussion so far and I agree with what has been said in the responses. Its very gratifying to see that some Geocachers are very genuinely concerned with making a serious contribution to the preservation of the NGS control network.

 

Here are a few things that may help to clear up the ambiguity.

 

An "approved agency" is one that is capable of performing geodetic measurements of the highest order and providing verification documentation in a technically precise format, so obviously no hobbyists would qualify. The Power Squadron is merely a group of hobbyists whose results are very often inaccurate and are not taken seriously by surveying professionals. They are by no means an "approved agency".

 

Its true that NGS, having essentially completed their original mission of establishing a nationwide control network, has had their funding dramatically reduced in recent years and is now focusing their attention on other tasks, such as developing "next generation" control known as CORS (Constantly Operating Reference Station) technology, based on state-of-the-art GPS. Therefore, they have basically entrusted the care and perpetuation of the existing control points to local public agencies and private survey and engineering firms. NGS has no real interest in these points anymore, but their mission statement compels them to maintain the database and continue to catalog whatever info they get from the public. The existing control network remains vital to thousands of local agencies and businesses that need to use it and they have created their own records of the points within their area. Therefore, even though the NGS database may seem to indicate that a point has not been visited in many years, it may have been used hundreds of times by local professionals who simply did not feel obliged to take the time to send in the documentation to NGS to update the record. I know this because I have been locating and using these points for nearly 20 years.

 

The term "recovered", which is often misunderstood, simply means that the station was visited, found to be intact, and properly documented. It does not mean that the point was removed, as some have thought, and it does not imply that it was ever considered lost. For many years, while the USC&GS, and thereafter the NGS, were actively developing the network (from about 1865-1980), only professionals submitted recovery forms, which were highly detailed and time consuming to fill out. As a result, compliance diminished over the years, to the point where professionals very seldom bothered to file the forms anymore. In truth, there is no real need to do so, since the points they are using are well known to all local professionals and have been incorporated into local records, which are more useful to them. The exceptions to this, of course, are those markers in remote, undeveloped locations, which may never have been needed for any projects yet, and therefore have not been used, or even visited, in many years. I would encourage Geocachers who wish to make a real contribution, to seek out such points and to properly document them.

 

Thanks again, to everyone who has taken advantage of this opportunity to learn about the significance of the NGS control network, which some of us like to think ranks among our nation's many great achievements, and to pass that knowledge on to others, along with the need to respect it.

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I'm a bit puzzled here, and possibly misunderstanding what a "scaled" location means.

 

I search for benchmarks in a suburban area. Many of them have a "scaled" location. Does that mean their coordinates are derived from scaling a map (perhaps an old 15-minute quad)? If so, it seems to me that geocachers giving coordinates +-15 feet with a toy based on satellite technology is better than a location based on scaling from an old map.

 

Are the really old benchmarks still useful for professional surveying? How accurate are their locations according to the professional grade sub-centimeter GPS units?

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As much as I hate to contradict survey tech.. but according to the contributors list at NGS..

 

USPSQD US POWER SQUADRON

 

is an approved agency...

 

But, then again, so is the US Supreme Court!

USSC US SUPREME COURT

"Ok, Sandra, you grab the transit; Clarence, you grab the rod; John Paul, you grab the tape... and we will see just how far apart the White House and Congress really are!"

 

>Personally Responsible for the Recovery of .00176% of the Benchmark Database!<

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Well about accuracy how are we finding so many bench marks,and cache's if the System is not accurate? There are other reasons,(in my opinion)why! but will not go into detail about those matters quite yet. Before Executive order 12906 on geospatial data, I worked on some marks that are 1st order, without data sheets and only using GPS, and the Geodetic scale for our area 36*-37*, the accuracy will astound you!!! this was with/S.A, selective availability, which is now turned off. Like the Scientist told me before 9-11 your trying to be too accurate , now its we are glad you were so accurate. Persistance pays in the end, Target aquired in PURSUIT.

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BDT

Yes, scaled coordinates are taken from maps and are only approximate. Remember that the coordinates of a benchmark are not of any real importance, since benchmarks are only used to determine elevations, not locations. You will never see scaled coordinates on a horizontal control point data sheet, these are all precisely measured, and the old ones are just as valuable as the new ones. You may report your coordinates for benchmarks, but surveyors use the descriptions and not the coordinates to find these points, so the precision of your coordinates is really a moot point.

 

Raouljan

Yes, everyone is approved to submit data, but as many geocachers have noticed, the PS does a very indifferent job of looking for markers, often giving up far too easily and declaring them "not found", only to be found perfectly intact later by others. I would hope that geocachers, rather than merely trying to emulate their low standard, would do a much better job of seeking out and documenting points. My reference to approval was intended to support what K&S said earlier, regarding those who may be approved to submit coordinates for inclusion in the network.

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I hate to grind this on... but

 

If you go to the official recovery form, there is a place for "approved agency code". If you are not a member of an "approved agency" you must enter INDIV (as in a "private individual").

 

Granted, the PS updates are usually in the "Recovered Good" class .. which is probably acceptable for a mark that has not been visited in 50 years, but hardly adds anything for a mark that is only a few years old.

 

I know that the Geocache community can do a better job than the PS. I would like to see Groundspeak get an official designator. Then we become, well, historical icon_biggrin.gif

 

>Personally Responsible for the Recovery of .00176% of the Benchmark Database!<

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I hate to grind this on... but

 

If you go to the official recovery form, there is a place for "approved agency code". If you are not a member of an "approved agency" you must enter INDIV (as in a "private individual").

 

Granted, the PS updates are usually in the "Recovered Good" class .. which is probably acceptable for a mark that has not been visited in 50 years, but hardly adds anything for a mark that is only a few years old.

 

I know that the Geocache community can do a better job than the PS. I would like to see Groundspeak get an official designator. Then we become, well, historical icon_biggrin.gif

 

>Personally Responsible for the Recovery of .00176% of the Benchmark Database!<

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I have reported a number of my finds to NGS, but the only non-find was a station in which the disk had been clearly removed, leaving a stub of its original metal attachment. Perhaps I'm mistaken, but it seems to me that an *accurate* 'not found' report might be more valuable to professional land surveyors and other professionals than a 'found' report, since it would spare them the valuable time of searching in vain for something which no longer exists. I emphasize *accurate* since obviously it is a disservice to suggest a station no longer exists when the real problem is that I couldn't find it.

 

Many of the marks I have found so far are in suburban areas around Washington, DC. Some clearly indicate regular use. For example, the surrounding concrete mass is spray painted a bright color, or the adjacent street is labeled with the designation, or there is (relatively) fresh surveyor tape festooned about. On the other hand, other stations I've found have been quite overgrown and give no evidence of having been occupied for years. It is certainly possible that many newer professionals may have never had occation to visit stations I am visiting, and it is also my opinion that sometimes the 'to reach' descriptions are a bit obscure. For that reason, I sometimes include in my NGS reports directions that I believe will be easier to follow if perhaps lacking in the precision of some of the descriptions before me. In one I recall there was a nearby cross street that was not mentioned in the description. Even though I didn't have a measuring device with me and was thus able only to estimate the distance by pacing it off, I believe the additional information that the station was "approximately 120 feet south of Green Lane" will be helpful. Likewise, I have updated (or corrected) names of geographic features, numbers of power poles, added house numbers, etc. In the area where I do most of my benchmarking, local surveyors can be presumed to have a general knowledge of the area and the ability to read a local map, so 'to reach' directions from distant intersections, which may have been useful many years ago (and certainly remain useful in rural areas) seem kinda silly now.

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I'd like to know whether those decapitated marks would be "not found", "found, poor condition" or "destroyed". I've found one of those myself. I'd guess "found, poor condition" from the NGS form (which says "destroyed" is only if you find the disk separate from its mounting or otherwise disturbed)

 

About the only 'good condition' recoveries I'd consider officially reporting are those where the roads have changed so much that the directions make sense only to those who know the local highway history.

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In such a case "found in poor condition" or "found damaged", followed by a complete description, including which if any reference objects remain and were used to define the location, would be most appropriate. "Destroyed" would be inappropriate, because even a damaged marker can sometimes be of use. This is particularly true of the decapitated ones, if they have a subsurface mark that remains intact. Visit the Berntsen site and note how their breakaway markers are designed. This is because property owners often destroy or move surface markers in an attempt to commit land fraud, but they do not realize they have left the subsurface portion, which the surveyor can still locate and use as evidence against them.

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i may repeat what has been writen already, but bear with me.

 

first of, im from newfoundland, canada so i will speak from a local point of view. i agree that reporting bench marks as destroyed or found intact may have some value. but how do you determine that a bench mark is destroyed? recently i was surveying in an area that had some recent water/sewer work. our gov agency reported that the relevant bench marks (brass plugs in concrete pilings) were intact, but our municipal government decided to bury them under a foot of class a gravel on the road side and not report it.

 

similarly our government assumes that all bench marks are intact, so of what good would reporting an intact find be?

 

simply put, i spend most of my day looking for survey markers and cannot think of what advantage could come of me reporting any information derived from a gps reading that could result in me having to search a 1200 sq ft area if my gps has an error of 20 ft.

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I'd be curious to know if BillP3rd got his question answered to his satisfaction or not. It seem that he has opened quite a can of worms...

 

If I may, like Raouljan, "grind this on..."

 

Two things that seem to keep going around in this discussion are the terms "recovery" or "recovered", and "approved agency". It seems that although there are varied opinions on what they each mean, for the most part, we all seem to agree. The opinions about what we can, or cannot do about them are quite different though.

 

One issue that has not been brought up here, or in any other threads that I've seen, is the issue of liability. For the most part, those in the Geocaching community are not surveyors, although I have found many with surveying experience and/or interests. In the State of California, and I would assume in other States, in order for an engineering office to practice, or even claim to practice surveying, it is required that a person in that office be duly licensed by that State to practice surveying. That person is responsible, and liable, for all aspects of surveying done by that office. (If there is more than one license, the liability can be shared.)

 

If Geocache.com or Groundspeak were to become an "approved agency", who would be willing to be that responsible person or persons? That person would have the responsibility - and liability - of anyone who reports on a benchmark in the name of Groundspeak, whether the report is right or wrong. It should also be asked: Who would make the determination that the reported benchmark really is missing, destroyed, obliterated, or intact? It seems to me that most cachers and/or 'benchmarkers' give-up, or figure the mark is gone, if they don't find exactly what they think should be there. A broken cap, for example. How deep would a cacher be willing to dig before they declared a benchmark missing. I have personally dug up benchmarks (and PLSS section corners) 12", 18", and 24" deep. The worst (by far!) was 46 inches deep! Who would be willing to be responsible for a claim that it is missing, only to find that the person making the claim didn't bother to dig at all.

 

I've seen in other recent threads questions about "is the use of a metal detector 'legal' for benchmark hunting", "what defines found or not", and "what is the difference between this type of cap or that type." If I could quote SurveyTech from the thread begun by Black Dog Trackers about different types of benchmarks, "...the extensive scope of what you are seeking to learn really goes way beyond what can be readily described in a forum such as this. Alot of what you are asking are things that are only learned over a long career." Surveyors are trained to look at all of the evidence of a benchmark in order to make a determination about it, and sometimes there is more evidence than what is on the NGS data sheet.

 

Let me say again: Have fun with the benchmarks you find and enjoy the history they represent. The network that the benchmarks are comprised of really is one of the greatest, and oldest, achievements of this Nation. If you find a benchmark that is not in the NGS or Geocache database, you could do research, beginning with the local agencies, to find out more about it. Someone set it, and if it is still in good condition (or even if it's in bad condition), someone probably knows about it.

 

Keep on Caching!

- Kewaneh

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The reason the practice of surveying is licensed and regulated is that a surveyer provides the legal description for real property.

 

Most of the "though stuff" in surveying has to do with traverse computations and area calculations, which is far outside the scope of the discussion here.. but they are the issues that generate "liability".

 

If liability in benchmark recovery was such an issue, why would our good friends in the PS bother to do recoveries? Given the flaky data that they (on occasion) submit they should have been suied out of existance long ago!

 

So folks, there is a big difference between recovering a benchmark and providing the legal description of real property.

 

Let's look at the exercise this way.

1. Submitting GPS coords for a Horz control is not worth the effort. The equipment ant techniques used to establish the original position are far beter than anything we can provide.

2. Submitting GPS coords for a Vert control has some worth as the scaling of these coords is +/- 6 seconds and while 6 seconds is a short period of time, it represents a LOT of rocks, trees and water buffaloes to negotiate while looking for a little brass disk. If we can provide a reading that will reduce the find time, then we are providing a service.

3. Destroyed controls get a bit trickier. Jist becasue you can't find something does not mean that it is destroyed. Photographic evidence is called for here, or perhaps 2nd party verification.

4. Digging for benchmarks and how far down you go is between a hunter and his/her entrenching tool.

5. Updating descriptions and directions is probably the greatest service we can offer. This is especially true in areas that undergo a substantial about of "re-engineering".

 

Remember... these marks are not just used by licensed surveyors, who probably know their local marks better than they know their children. These marks are also used by people with zero local knowledge, who are in the field for a short period of time and have neither the time nor resources to engage in a long hunt for the brass. This includes geologists and other "field scientists" who have no interest in legal describtions.. they just need the control to get to some other location.

 

>Personally Responsible for the Recovery of .00176% of the Benchmark Database!<

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