evenfall
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Posts posted by evenfall
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seventhings -
How did they update their latitude? Astronomy?
Yes, the stars were used. Also, Triangulation, Trigonometry and Least Squares Adjustments.
Not all measurements were purely Linear. They were Optically and Mathematically cross compared to many other observations many times, many ways, to remove cumulative errors.
Rob
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"w of GP, BGL.1.2 M S of C/L"?
Hmmmm,
West Of Gore Point, Below Ground Level, ( Could be Below Grade Level also, the paved way being considered the grade being referred to) 1.2 Meters South of CenterLine.
We are talking 1.2 meters here... almost 4 feet. If it is near a centerline of something, it may in fact be BGL, Below Ground Level, as in Paved over.
Rob
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I've been out four times now, finding benchmarks, learning a bit each time, and enjoy it in combination with geocaching. I've learned about bringing Brillo pads, Brasso, emery paper, and sulfuric acid to clean all those little brass discs! I did notice that hitting the brass, and pounding them back into the rock laves some fair dents. Wonder how others do it?Stonedust,
Well, I can say that everyone has to start somewhere. There are 3 pinned topics at the top of this forum, and I would suggest reading all three to learn about this. In addition, we have already written volumes about everything in this forum, so if you are a hardy reader, all of the Forum Content is archived so feel free to look back through it. Each members posts can be looked up as well if you find a particular writer or 10 here who you feel you can learn a lot from.
You may find that after touching base with a lot of that, the Battery Acid and Brasso are likely not things you really need. Hunting these things is a lot more about Brains than brawn. If you can come up with the riddle of why some here use Cornstarch for hunting benchmarks, you will have probably combed through a lot of other useful knowledge.
I can tell you this much, around here, we learn something new every day. That is how a lot of others do it and a long journey begins with the first step.
Good Luck,
Rob
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Spoo,
I would write Berntsen, http://www.berntsen.com/ which is who I think you bought your survey marker from, and ask them if they differ the metallurgy from batch to batch, or something like that. I would not think think the reason would be field stamping, but it is true that there are different materials used, and perhaps they can shed some light on why.
DaveD may be able to shed some light on the Standards NGS has had for metallurgy requirements on survey markers over the years. I have read there is a evolving rhyme or reason to it, for longevity and corrosion resistance purposes, but I don't remember just where at the moment.
I would guess the large scale buyers of survey markers can spec the order in most any way they like...
HTH,
Rob
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If Vertical Control is missing the disc, I cannot use it as Legal or anything else. It is rendered inaccurate. If it does not agree with the datasheet, it is destroyed.
Mounts in vertical surfaces no longer show where from which the station is to be measured, so... Now what?
Just remember, vertical control must be physically touched to be measured. If added to or taken away is happening, then there is no Match, It must match. If not, then it cannot be used.
We think of it as destroyed, but Poor with a note that the disk is missing will tell me I can't use it. an no surveyor ever will again.
Rob
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What we need to keep in mind is that NGS applies the logic of David Hume's Empiricism to their survey markers. If you cannot bring them a pound of destroyed survey marker and show them, then it ain't destroyed.
Hume was not sure coal would burn unless you threw the chunk in the Fire, Next Chunk? well that was also an unknown until in the fire and burning... and so on...
When you understand the reasoning, it makes it hard to arbitrarily destroy anything. That could be bad for a database... it would leave it wide open to abuses that are not wanted.
The bottom line? If you didn't find it when you didn't find it, then you didn't find it. That two cents worth and what you did to try, is worth a lot.
Rob
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Again, one of the very cool and innovative niceties that Benchmark Hunters provided for themselves.
Thanks Matt,
Rob
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Ok, I'll Bite...
>I'd like to know who to contact when I find obvious benchmark database errors.
At Geocaching? No One.
However the correction you think you see needing made may not be an error. The finders, GPS'rs could be wrong.
>For example, there is a benchmark, when accessed by the Muskellunge Lot D, etc (QM0472) in N WI description and coords ,
Accessed How? At geocaching? Can you provide a link?
>takes you to a whole bunch of GPS enthusiasts who figure that this is the Muskellunge Tower benchmark, which is well documented with coords and pictures.
They Figure It is? Figuring is not enough.Are you saying that you confirm they are correct or in error? I am unclear on this?
>I can confirm that those coords , and is confirmed by multiple GPS'rs and a close proximity cache (GC2149)
GPS'rs? Geocachers or Benchmark Hunters? Not to say that one is better than the other, but they do approach the work a bit differently.
You can confirm the coords the hunters provided in DMM formatting, or, you can confirm that the coords match an NGS datasheet in D.M.S Formatting? The numbers are different and can mislead by a longer ways off than people think.
>However, a search on the geocaching.com site for a PID with the same QM0472 becomes a Lot D benchmark in Oneida Cty, many miles away.
Which is Likely the real Mc Coy, with a higher level of trustablity than what most Geocachers can approach. Sure there are Mistakes, and we find them, but, there is a method to proving this, and it is a pretty strenuous test most of us put this through.
>The caching db is as good as those who provide the data.
And there are errors, and often so.
>For those of us who occassionally like to 'do' benchmarks, errors like this should have an easier way of reporting.
Sure, but Geocaching does not make this data, nor do they correct it, they just provide it for gaming purposes and it is a 5 year old listing. The real one is corrected all the time.
>I'm not going to suggest that somebody who has a few decimal degrees of argumentation should modify these records. But a reporting form or authourity would be a wonderful addition.
There is an authority, and if you hang around here, read the three pinned topics on this forum and keep up with this forum, you will learn a lot. I'll not tell you just now, but I think if you hang here, you will figure it out on your own.
>Benchmark information is a somewhat different animal than geocaching,
VERY!
>but I believe we have a responsibility to provide the best information at our disposal.
YOU can be a part of making it better! :-)
That is a great way to approach this. Feel free to read the old threads of this forum and ask more questions!
>Responses are welcome
Thank you.
Rob
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I would not over think the little things we notice differences in the survey markers too hard.
There are two basic markers. One will be about Height, known as a Bench Mark. One will be about Horizontal Position. It could be called Triangulation or GPS but are about a Latitude, and Longitude.
In a basic way, GPS uses a Radio Triangulation Scheme in the 1.5 GHz part of the Radio spectrum to do this. The GPS receiver uses "Triangulation Mathematics" (Trigonometry) to determine where it is as based on the radio signals it receives from the Satellites in space.
Just let the words on the disc remind you of these things when you see them, and let the datasheet for the disc tell you what kind of data, and the quality of the data you have on any particular station.
The advent of GPS has muddled what kinds of Data are actually ascribed to a Mark. These days it is easy for a mark to have both, or be given data it never previously had.
Hope that Helps,
Rob
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I hope benchmarking doesn't move to waypointing. I would miss it very much, and move on.
Harry,
That is something you could write to Jeremy on the Groundspeak Website Forum. You are a Forum Regular and an active hunter. Your feelings are something he is aware of. Others who feel as you do might consider doing the same.
Rob
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Here is a photo of the shiners we commonly use, when we use them
http://www.evanschristmas.com/evanss/produ...tail.asp?ID=152
There are many brands, we are apt to use what there is available.
I like to nail them down with a concrete nail, or a Mag Nail, which is also magnetized so it can be more easily found.
Rob
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I Have been sending mine in to deb.brown@noaa.gov Debbie is very happy to collect them. She is archiving them and they will be added to the appropriate PID's and Datasheets as the changes Casey mentioned come on line.
Just bear with them and send those Photos to Deb!
Good Luck,
Rob
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My sense of this is that I cannot speak for anyone else's find, or not find.
I can only speak for my own work.
It would be risky to assume that I could write an adequate recovery with current description based on a lack of local knowledge. It also leave people open for people leaving false info out there in hopes of it corrupting he database if copied.
NGS recoveries do allow you to back date to the date of actual recovery, even if it was some time ago. this is all well and fine as the dat you said you were there and the conditions you found would be accurate to that time. It would not be true if you filed a recovery of today''s date for something you visited a year ago, as things could have changed and you would not know.
Updates to the NGS Database are all 100% Monitored, but it would be poor form to waste the NGS man hours with recoveries that were not performed by the reporter. The NGS database deserves to be treated with a High level of integrity and it would only be appropriate for the person or people who were actually on the recovery of a station to be the ones to report it to NGS, should they choose to do so.
Hope that helps,
Rob
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Want to add your wishes to the list of wishes here on the Groundspeak Forums?
Here is an example of when it works:
http://forums.Groundspeak.com/GC/index.php?showtopic=108501
Just start your thread on this Forum:
http://forums.Groundspeak.com/GC/index.php?showforum=8
And invite some other Benchmark hunters to get behind you and chime in. Maybe Jeremy will like your idea or give you a good answer as to what his thoughts are. You never know!
Rob
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To be really certain, you cannot really know until you see for yourself. Geocaching logs are unofficial and maybe the regulars in the area have not gotten to it or have not found it, yet.
It never hurts to go see for yourself. You can't honestly write it off unless you do.
Rob
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In the big scheme of things and with few exceptions, (regionally speaking) even surveyors must obtain permission to enter private property.
It is simply good form to ask in advance and never argue if you don't like the answer. Simply ask and accept the answer is what we have to do. When you think about it, you would want your private property respected as well.
Hope that helps,
Rob
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The FAQ will say you must read the brass disc, and this station is a brass disc, so you cannot log a find. If I were to use it for survey reasons, I would need to use the disc as well. This plate will do nothing for a Surveyor.
It would be up to you if you want a look under the plate. If you do remove the plate, please remember to replace everything as you found it.
Good luck!
Rob
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Terra,
When a road is widened, and the widening is along side a ditch or deep waterway, we dig a new channel for the waterway, move the water to it, close off the old waterway and de-water it. Then we remove all the Topsoil, muck, organic materials. As we go we also remove the man made bridges, culverts headwalls and other structures in the area we intend to fill in.
Filling in requires that once all the structures are removed and the unusable soil is removed down to structural Material such as Original ground less topsoil, we then begin filling the ditch with a structural fill material that meets quality standards and it is compacted to the right amount of compaction that the engineers have determined adequate for that soil type. After that, utilities may be placed in the new fill, and the road widening with perhaps concrete curbs, sidewalks, signal control, street lights and asphalt paving.
Every detail is built to surveyed accuracy.
If the road was widened and the headwall was removed to facilitate this, then there is the demise of your station. If you like, you could send a note of not found to NGS detailing the lack of a headwall and a widened road. It would save someone from wasting time on it in the future.
If for some reason the mark was not considered publishable during the time that geocachings copy of the database was being distributed, it may have been left out of that version of the database. We find things like these more often than you may think. NGS has track on many stations it does not currently publish. It is doing maintenance on the data all the time.
Good Luck, Hope that helps.
Rob
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Art,
I believe it was both Zhanna and one other, Maybe Blackdog, Buck Brooke or Harry Dolphin who were talking Bookmarklets while back.
Spoo,
Yes, what you have discovered is a Bummer. While back I tabled a discussion hoping to get a consensus for asking Geocaching to drop the old static database and recode to use the active and constantly updated NGS Database as a feed for Geocaching's. Complete with backward compatibility for lost marks which had been at one time found of course. But no one could agree on why it was important or how to do it and it faded to nothing.
I still think it as Doable and Viable. I also have a sense that if benchmark Hunters do not unite in a consensus, and speak to geocaching in one voice for some things we would like to see, that none will happen the way we would prefer. But building that consensus has not begun to become successful...
Maybe someday after geocaching changes everything and we all hate the outcome, maybe then, eh?
Best regards, Rob
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KCMOWMAN,
Well said and for the most part, not too far from the Mark.
Sorry about the Erudite appearances here but the folks are pretty good folks, and a lot more genuine than you might think. You just have to get to know them.
Going to the Prod you hope to wield, The staff of Geocaching really do not keep an eye on this forum nor cater to it's needs.
I'd advocate that if you like the squeaky wheel method would be to email Groundspeak directly, or Jeremy, the CEO. If nothing else, they do keep a closer eye on the Geocaching website forum, found here:
http://forums.Groundspeak.com/GC/index.php?showforum=8
It is moderated by Jeremy, so he keeps a close eye there. That is where I would post my requests if it were me.
Good Luck. I hope your added voice will help the cause.
Rob
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Are you a Benchmark hunter, or are you new to the hobby but want to ask some serious questions about what survey markers are and how to find them?
Have you gotten to the point where you re good at the game but want more?
Has the benchmark hunting "addiction" become so disproportional that you must have more?
Do you feel civic minded and feel doing Volunteer Work would be a nice way to give something back to your community and your country?
Do you want to just dig in and talk Survey Data, and How to find the really hard ones?
Do you want to talk about Geodetic Quality, Datum? Survey History? Have you ever wondered about Bliby Towers and the height of the light? RTK GPS Survey Equipment? What a CORS or OPUS Station is? What Happens to Lost Benchmarks?
Do you want to ask questions directly to the National Geodetic Survey and get answers from Surveyors who work in the Field or National Geodetic Survey (NGS) Representatives?
We have a place you can ask those questions without confusing the concepts of the Game Play here at Geocaching.
Please have a look at the NGS Forum created just for those kinds of Discussions here at Geocaching:
http://forums.Groundspeak.com/GC/index.php?showforum=40
Feel free to start a thread and ask your more technical questions there. No Question is a Bad Question. See you there!
Rob
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Have you found a Brass Disc or Survey Mark not listed Here?
Frequently, we are asked what to do when a benchmark is found which does not seem to be listed on the list of known Benchmarks here on Geocaching.
There are a lot of optional answers, but before we start with the the questions, Please have a look at the Benchmark Hunting FAQ to see if there is an answer to the question you have.
Here's the link to Geocaching's Benchmark Hunting FAQ:
http://www.geocaching.com/mark/
Good luck and Good Hunting! Please feel free to start a thread in the forum should you have a question the FAQ doesn't answer!
Rob
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One of the hopes that was a part of the creation of this forum, was that the people trying to recover Survey Markers for NGS, as well as those wanting to have the more serious technical discussions about the Surveying field and monument recovery tips, tricks and difficulties, could have those discussions here.
Let's not lose this opportunity to use this forum space to it's highest potential. Please consider bringing the difficult finds, and tough questions here, even if all you intend to do is play the game, and try to keep the lighter subject matter in the benchmark hunting forum. It would be the highest and best use of this forum.
Let's not under use this Forum!
Thanks!
Rob
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Not trying to be rude but, the saying "you get what you pay for" might apply here. With support the database, can and has been updated, without support benchmark databases will fall behind the more central focus of geocaching, IMO. If is a cost issue, what do you feel is a fair price to pay for access to this amount of data?
Frodo, I don't think you were rude, but let me play devils advocate here.
Your adage also applied to the payers... The payers don't get what they do pay for. Especially if all they like is Benchmarks. So what about them? I am sure if Geocaching were to add a cool pay feature, many would want it, but perhaps it is not time yet.
Geocaching has never provided anything benchmark for premium , ever. It was their business decision to provide what they do for free. Their Choice.
In return they do provide the forum space and recovery log areas. Free, their choice. We have been grateful.
The data they supply is already provided by the US Government, for free. It is a public service. Geocachers who choose to benchmark hunt have many options here and many choose to pay it forward with public service.
The hope has been that someday, benchmark hunters would get PQ's and I am sure many would pay. Yet, it has not happened as yet.
Either way, Lots of bills are getting Paid.
So I think it comes down to joiners join, and those who don't, don't. They all have reasons.
Rob
I've been out four times now, finding benchmarks, learning a bit each time, and enjoy it in combination with geocaching. I've learned about bringing Brillo pads, Brasso, emery paper, and sulfuric acid to clean all those little brass discs! I did notice that hitting the brass, and pounding them back into the rock laves some fair dents. Wonder how others do it?
What County Is This Marker In?
in Benchmarking
Posted
Rog,
Cheryl and Deb have a County Mapping program they use which NGS has deemed ok to use for determining which county a station is in. They will put the the station coordinates in : NAD 83(1986)- 36 32 43.93860(N) 078 08 17.79911(W) ADJUSTED, and see where it lands, then they will make the judgment from there.
If it seems too close to call, or you feel the software you are using cannot properly discern this, please feel free to email it in to them for determination.
Rob