evenfall
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Posts posted by evenfall
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Jerry,
While you are in the reply mode here on the board, just above the space you type into there is a bunch of code buttons which are html tags and such. You will want to select the one labeled "IMG" to upload a picture. Just remember to close the tag when you are done. There is a test area here in the general area on the board to fool with the learning process without interfering with the other threads.
Rob
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In Lieu of the NGS site which is currently having server problems, it seems to me that there may be a work around. I cannot say for sure as I prefer to use the old paper technology method datasheet from NGS and have no way to test this theory...
Anyhow, on the Geocaching Benchmark nearest mark search page, after you perform a zip code or coordinate search, there is a button there that says, "download all results to *.loc". Will this list that is downloaded from the geocaching website's database work in lieu of downloading from the NGS site, for those who use Palm pilots and such? If anyone knows whether or not this method will serve as a work around until NGS has resolved their server probs, please weigh in on that. At least it will keep you going in the interim.
If it will work it seems the appropriate zip codes for places inside Amador, or any other county will get you where you need to go.
Rob
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Thanks Jerry, and welcome here. There will be plenty of Q & A going on in here and the more the merrier! Nice to have you weigh in on this, and we hope to see you more often. Happy Thanksgiving.
Rob
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Tayjam,
Can you provide the PID so I can read the description? Without any more to go on than a wag, I am assuming rivets on steel bridge work.. Mui Big Rivet. Thumb sized. and lots of em'... They leave a good sized bump and last as long as the steel stays put. Old school steel work all that.
Rob
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Bill,
These are common practices...
Railroad is usually referred from one of the rails, pick one and define it. East rail, west rail?
Which would you use, the edge or center of a sidewalk? Edge is best. Defined as front or back of walk, as seen from a street
Curbs can be defined as Flowline, Face of Curb, Top of curb, Top Face of Curb, Top Back of Curb... Tell us from where YOU measured. Top Back of Curb is most common, followed by Face of Curb.
Where on a fire hydrant? Top Bolt is most common practice.
The edge of the concrete box at a storm drain, We commonly use the edge or corner of the grate and define which one by cardinal directions
the edge of the manhole , or its center? Center of manhole is the only consistent location on a round object.
What about a road that has an obvious joint in the concrete but that isn't the middle of the road?
Centerline of road is always in the same place no matter where the cracks or joints are. Measure edge to edge and divide by 2.
Rob
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Hi Holograph,
This is a great question, I an glad you asked.
A Compass and 100 foot tape measure would be very helpful but there is a work around.
You did not say what kind of GPS you own but there are maybe some tricks you can use, should you have one that has enough features.
Ok, To Begin. NGS recoveries are in NAD 83 Datum, ddd.mm.sss format, so it is best to use that format on your GPS when dealing with them. It is especially important if you intend to cite the GPS waypoint you made in your recovery. It is a big help in describing the station especially on vertical control. It is also best for you when working with their datasheet, and it is best to work with their datasheet because the geocaching website conversion of format, rounds off some of the accuracy when they convert to ddd.mm.mmm format. Also when you are standing on location you will see that all the numbers match with no need to convert them.
Making a Waypoint for the Station by placing the GPS on the station and waiting for the highest accuracy you can get is best. Then include that coordinate in your filing. This is really only necessary on vertical control points, not for triangulation, or horizontal control, as these are already at a higher accuracy than your consumer grade GPS can reveal. You can determine what kind of Station you are recovering from the NGS datasheet.
Next check the settings in your GPS, If it has a compass, the compass heading north reference should be set to true. Not grid or magnetic. Now, stand at the Power Pole and run a go to to the waypoint you made for the survey maker. The GPS should give you a bearing and approximate distance to the survey marker. Then you could say "the the station is approximately X feet or X tenths of a mile N.W. of the power pole bearing 345 degrees". This is better than paces as nobody has the same stride and terrain can mess up paced measurements. Also double check this measurement 31 FEET WEST OF THE CENTERLINE OF THE ROAD. Is it still good? I ask because the centerline of unimproved roads can meander.
So your filing could say the tree blazes are no longer good, (do not re blaze the tree!) That it is X feet west of and at a right angle to road centerline at NNN degrees and X feet nnn degrees from a power pole on the opposite side of the road.
Feel free to look at other descriptions of stations to get a feel for how the technical writing style seems to go. Then just be as succinct as you can, while describing it as best you can. Most importantly if you have any more questions, ask anytime. Writing recoveries is not that hard once you have a feel for it.
Thanks, Rob
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When dealing with the public, it all really all comes down to how you frame the conversation for them, You cannot let them run you too hard...
I just stand there in full gear and listen to them with my hands in my pockets... Depending on their attitudes, I go from a forthcoming explanation, to something like "oh, the city is planning on putting a big petroleum pipe line through here and we are just getting started", or a road, or tenement housing, If I am really feeling sadistic I may say a WalMart with a huge parking lot. Be creative I always say.
Then I step back a bit while they TAZ out for a few, and after the froth settles, I just say, "Naw, I'm just checking on a real old old survey marker to see if it is still here. But I had you going there for a sec, eh? :-) They usually go away pretty happy.
Surveyors are kind of sardonic you know. It comes from slashing through blackberry bushes in the rain, dipping clogged up old sewer man holes for pipe invert elevations, and other particularly unpleasant situations... :-)
Full disclosure is a pretty good practice all the same.
Rob
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KSV,
If you scroll to the bottom of the main page for this forum, there is a setting there that allows you to manipulate how far back in history you want to go to read all about benchmark hunting. There is some excellent reading back in the archived area. I'd encourage anyone to look back further. You can read for days. If you do nothing at all except read what is on the page as it displays in default mode, you will likely be busier reading more than you will probably want to be in one setting. One of the top four pinned topics will more than get you started. You will come away with a pretty well rounded idea.
Please, feel free to ask anytime. Hope that gets you where you want to go.
Rob
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You are correct on the calculator Ted, I have been quizzed on that before. Thanks for noticing that! :-) But the 16th is only the quantity that 40 acres is of a square mile. In PLSS terminology, something they started waaaay before I came along, a Quarter-Quarter is 40 acres... They mean it as a quarter of a quarter section.
A Township is six miles by six miles square, there are 36 sections in a Township, each of which is one square mile. A section = 1 square mile= 640 acres. A quarter of a section is of course a quarter section, 1/2 x 1/2 mile square containing 160 acres... A quarter-quarter is 1/4th of a quarter section 1/4 x 1/4 mile in size or 160/4=40 acres. (I was in error when I mislabeled it 1/8th in my earlier post, thanks for the proofread!) Back then, that was thought to be the right size parcel for a homestead. If a parcel of land was smaller or larger than 40 acres it was called a Government Lot.
Confused? Ok draw a box on a sheet of paper, That box is representing a square mile, aka, a section. Ok, divide that box into 4 square equal sized boxes. Two boxes on the top half and two on the bottom half. Each of those is a Quarter Section. Divide one of the quarter section boxes into quarters the same way we did the big box. each of those small boxes represent a quarter-quarter. Not everything was always perfect sized, so hence the need fulfilled by the Government Lot.
If you still feel confused, watching the Coyote chase the Road Runner helps me :-) Other times I just go lay down until it passes! :-D If nothing else you can riddle people; when is 1/16th of a mile not a sixteenth of a mile? Your answer will be when the mile is square not linear. It ought to be worth a little free beer at the local watering hole.
About a week back someone asked where he could get maps showing Township and Range detail. I suggested going to the court house and seeing the treasurer and or the civil engineers offices. They often have maps that show how all the land is actually sub-divided and on the bigger parcels they may list the names of the owners. They may also have older versions of that map too. It is interesting to see how it is all divvied up. If they cannot supply, they can often tell you how to get one. Many counties, or a local Cartographer will offer these and other types of maps for sale for a fee.
Rob
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Geez that was funny!
I was just thinking of all the pieces of broomstick you will buy! Hehehe There are thousands of NGS markers you know!! :-D Soon you will be carrying more lumber around than I do! Besides Sword fights are nothing!
Trust me, when you are a surveyor you have to learn to laugh at a lot of stuff that happens... Things seem to go wrong for other people right before our eyes as well...
Did I tell you about the time an Asphalt Tack Distributor Truck stopped to ask directions of us while we were surveying along a right of way? The guy somehow flipped the PTO and distributor spray bar switches on while he was sitting there at an idle... The spray bar was in the folded up position just drizzling... I think it must have happened when he reached across to open the door on the passenger side to ask us... We had no idea at the time but he left a puddle where we were. As he drove away he began majorly hosing down every passing car that went by him as he went up the road... I have no idea when he shut off the spray... We were laughing so hard that we lost count at ten cars... When we regained enough composure we called 911 so the State could begin to clean up the spill... It was a mess... Conceptually funny to us at the time... Not fun for the asphalt company or the car owners.
Anyhow, glad you are having fun,
Rob
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One of the dilemmas facing all surveyors is how to preserve the actual location that the survey was performed. As a construction surveyor, I set a lot of temporary stations. We realize we will lose a lot of the survey as we do the developing work, but the stations served it's purpose and that was all that was necessary. I can tell you story after story about how many times kids out having fun after quitting time will pull up every Lath you set on all the stations, and use them to have sword fights amongst themselves clear across the job site, dropping them no where near the corresponding location they actually belong. All before the desired purpose had been fulfilled. You can well imagine that we have to go over our notes and figure where the stick belonged, or make new ones, making sure that the information on that stick matches the location that the specific work is to be done. In fact, I was having fun just like this the other day! :-)
Other times it is ornery neighbors who as a form of passive resistance are opposed to the development happening near their back yard, and so they will go pull up the survey. I have seen it go to a point on a few occasions where it became cheaper to have a night watchman to prevent the various kinds of vandalism than to re-accomplish the work so often. If not cheaper, at least it was more productive.
Another time I came home to a home I was renting to find that a neighbor had hired a survey done on one property line to update a fence and there was a new corner set. My landlord was going to be losing a lot of land if this was left to stand. That was not really what they wanted to have happen. Fortunately I was able to help sort it out. The neighbors property corner was mid way across my landlords yard. It was not a property corner for my landlord. I surveyed my landlords yard and found the back line was where it should be based on the platt my yard was in. That would reinforce an adverse possession situation if necessary, since there were existing fences. The discrepancy was found when I learned that my neighbors surveyor did not use the property description for the platt my neighbor lived in for the actual yard, but rather used the description for the field that was bordering both our yards.
The old farm field had been part of a divided up old government lot. A government lot is basically defined as a quarter section of a quarter section that is more or less than 40 acres. PLSS Township wise, that means a section, which is a square mile, is divided into quarters, and so a quarter section is a square 1/4 mile. This means a quarter-quarter is a 1/8th square mile and that is considered to be a 40 acre plot. On paper you have 640 acres in a square mile so 640/4=160 for a quarter, and 160/4=40 for a quarter-quarter. If a parcel of land is measured up to be smaller or larger than a quarter-quarter it is considered a government lot.
Most of this is sort of thing is century old survey in most cases, and the corner of that old field did not fall in the same place the plats did. When all of the information was looked at together, the plats were in sync, as the plats had the same POB or point of beginning. A different POB had been used years before for the old field. and there had been a change filed on one of the plats after the initial filing that further defined the situation. The survey's and complete research proved that the corner, should remain in it's original location. It was in the right place to begin with. We caught perhaps an old chaining error or something, and a Surveyor who could have done a more thorough job.
The highlight here is this. Survey is something that can be alarming to people. It can be something that evokes a negative emotional response. It can signify change, and unlike us in here in this forum, many people do not relate to the different things Survey markers can mean. elcamino made a great point. We do not know who may take offense to a survey marker. It is something well worth thinking about or keeping in mind when we find them laying on the ground. The marker is a really temporary item, but an accurate description in the database can last for years and years. You are welcome to buy the materials to make a marker if you like, but you could put that money in the kitty for a better GPS, mapping software or a metal detector... Food for thought!
Rob
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Perrito,
Again I come down on this differently that others will. I am in the surveying industry, and so that sort of colors my position on the matter. Many Surveyors in other areas will often have their views on this as well. There are other Surveyors who write in this forum who advocate replacing witness posts. I do not disagree with their reasons for doing so. I just go with what feels right for me. I have seen a lot of vandalism and I have had to re accomplish surveys due to the temporary nature of survey many times. I have never set Geodetic Markers in my Field but I do use them. I Often have to tie a survey into something such as the National Spatial Reference System. These particular stations, the NGS survey network is the National Spatial Reference System. It is the most accurate network established for use in Civil and other work in the United States, and I feel a little protective of it I suppose. When I recover a station I return it to the condition I found it. If it was buried and I dug it up, I re-bury it and I make note in my recovery how deep it was found buried. I do not intend to make them harder or easier to find per se, but I also do not attempt to make them more obscure any more than I try to call extra attention to them. I just let nature be nature and make notes of that. Nature will be nature after all.
The narrative portion of the description in the datasheet is the part that is provided to aid the person looking for the station to find it. Often it has been some time since this info was updated so we may choose to update it, but for the most part if this information was written well and items of relative permanence in the near vicinity were included in the description to help find it, then it that narrative should be able to serve as witness post enough. Here in the Northwest Washington State Area, I cannot say that the NGS never set witness posts, but I can say I have not personally been to a NGS station in this area that has had a standard witness post either physically there or referenced in the datasheet, yet I can still find the station with the datasheet. Who knows, I may yet come across an NGS witness post yet.
A form of caveat emptor is to replace the witness post in a place other than it's original position. If we are not clear in our description and overlook that the witness post had been previously used as a position to measure from to locate the station, we can make it more difficult to find the station at all. Our measurements lead us to nothing. People will use what is handiest, and so the witness post is pretty handy, but if it is not in the place it was described to be, it is of less help than if it were not there at all. If it is not there it can not be used to confuse the situation. Witness posts get moved all the time. Buyer Beware.
It is your call, do as you feel would be best, but I would not attempt to obscure it with a rock or use a rock to help others find it, as it could cause the station to become obscured more than necessary, and possibly cause others to attempt to obscure it further. This could cause a contractor or utility company to dig it up by virtue of not knowing it is there. Depending on the area, someone maintaining the area may not like having to deal with the rock later. I suspect a good many witness posts go missing for similar reasons. These things are no match when obscured to highway mowing operations, and how far will a witness post fly when hit by a big mower? Since the rock is such a temporary object, it really does not help in the form of a permanently describable item either. It always seems to me that in all the places I have worked with these stations, that nature will take it's course, unpreventably. I just try to describe the scene today as it has changed or evolved from the scene of the last recovery in the most permanent way I can, and go from there. The person with the updated datasheet next time is really the only person of concern to me. Who knows what they will find, maybe I will have helped.
Rob
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Hi John,
This part of the datasheet ---> 1/1/1949 by NGS (GOOD) is a computer generated part. It is a data entry error. There are approximately 1.5 million stations, both active and inactive in the NGS database. Data entry errors happen. These datasheets at one time looked like this example from elcamano. (thanks Mike!) This status item likely was overlooked when all these were typed into the database. If you like, you could easily get this corrected by emailing cheryl.malone@noaa.gov stating that you feel that this PID's entry should be listed as a (NOT FOUND) under the 1949 entry.
After you email Cheryl with the correction, you can also choose if you like, to improve the database by submitting your recovery to the NGS so they and other users of the database will know that the station is in fact still there. You can do this by writing your own recovery including the coordinates you took while there to improve the scaled position, in a similar manner to the way you are used to reading them off the datasheets and submitting them on the Mark Recovery Entry page at the NGS. It will be processed not too long after and the latest data, your recovery, will be reflected on the sheet that is found.
Also if you like, you can submit the pictures you took of your find to the NGS. They would love to have 2 pictures of it for their database if they could. One close up of the station, and an area photo with the station included in the photo. If you choose to do this, they would appreciate it if you could label the photos as such; If it is and close up, it could be labeled as an example: FS0619_20041116_C.jpg which is PID_DATE_ and either A or C for area or closeup. It would be best if the photo were reduced to 4x6 size and resolution should be 72-100 dpi. This will cause the file size to be under 100k and that is preferred. Photo editing software can be used to emboss the data onto the photo as well. Once the photos have been prepared as such, they can be emailed to deb.brown@noaa.gov and she will add them to the database as her workload permits.
An example of what this looks like on a datasheet is found on the NGS PIDS FORM by looking up the datasheet for PID GA2360. Scroll down the page a bit until you come to this line: GA2360.Photographs are available for this station. The word Photographs should be an underlined link. There you will see the photos that were submitted during the latest recovery of the station. At some future point all photo submissions to the NGS will be treated this way, and they are working on a webpage for photo submissions of this nature.
Anyone can take this on as a volunteer effort if they like. Of course all this NGS recovery work is strictly an elective process. The basic premise of benchmark hunting at geocaching is a game based on NGS survey markers and their data. No one is under any obligation to perform any of this work to correct the NGS data, yet all geocachers are certainly welcome to volunteer their energies to correcting the errors and reporting the status they find if they like. If we should choose to, the NAD 83 Datum and ddd.mm.sss modes on the GPSr will be most helpful for working with NGS data. The ultimate premise of all this is about having fun. By all means, if anyone needs further clarification from the NGS, they are a friendly agency and they appreciate geocachers. Please feel free to write them directly with any questions you may like further clarification of, or not, that is up to the finder, or questioner.
I hope that helps clarify what likely happened in this case for you. Thanks John.
Rob
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Perrito,
There are different philosophies on this.
Many people do replace them when they find them, Some feel that it calls attention to a survey marker that many would prefer to remain somewhat obscure. Vandalism to survey markers is a factor, The overall consensus is that they can be both a help and a hinderance all at once.
Professional practice in many areas of the country would prefer that people, including professionals, not pound in a witness post without knowing where underground utilities are located prior to doing so. Things change between the original time a marker was set and today. You can easily pound a metal witness post through a buried Power Gas or Comm line which has been direct buried very easily. Of course the obvious point is that you could be killed, even though it seems innocent enough. I am sure the chances are slim but are you sure? Without Locates, you cannot know where things are underground, yet to be sure there are a lot of buried utilities. The Law says that the person digging or otherwise putting something into the ground is accepting the liability for the action of doing so. The person who does damage to a buried utility is liable fore the costs of repair, period. I know a witness post is a nice gesture but the liability can exceed insurance coverage in many cases. I don't replace them, professionally or privately. I consider that someone will likely come along behind me and pull it out again, making the effort I went to, especially if I described it in a form of my recovery, rendered usless. I prefer to write a concise update to the description if necessary. I prefer reference points that are more permanent than a witness post anyway.
Use good judgment and common sense, there is probably no harm done in some areas, considering some places are very remote. Yet keep in mind, Your milage may vary. Feel free to do what you feel is best for you.
Rob
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Paul,
That looks a lot like an early 60's era Dodge... Me thinks. D5-700 series, from maybe between 62-65 timeframe. Dad worked for an outfit back in that day that only bought Dodge Trucks of all types and sizes. I got to see a lot of them. Feel free to compare pictures and data Here.
Rob
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I am posting here to add a link as a place holder to a forum topic that is worthy of keeping handy for future reference and consideration. This will keep this link from becoming lost.
Topic: Corrections ? - Benchmark Hunting Page - Faq?
Link: http://forums.Groundspeak.com/GC/index.php?showtopic=84002
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Bos,
Thanks for raising the points you did. They are good food for thought. It looks as if the FAQ could use some touch ups, and yet overall it does well. Some of the things that you call attention have evolved since the last FAQ update.
That said, the NGS has been evolving ways that they with benchmark hunters. They are very happy to have our help. Dave Doyle has not only Deb Brown working with benchmark hunters in the recovery efforts but has recognized our efforts and added Cheryl Malone to this work and assigned a Liaison, Casey Brennan as well. The NGS is very interested in the work this community has been doing and are shuffling resources around so as to accommodate it.
Within the forum here, there is a lot of evolving going on as well. We as a group continue to do what we enjoy, and through sharing our discoveries and for instances, we all become exposed to a lot of fun, interesting, often anecdotal instances from which we all learn something new as well. I would say we as benchmark hunters are evolving in the ways we hunt as well. This entire forum is like a library filling with information, and everyone who contributes takes it new places all the time.
This thread too will serve as a chapter as to how we can improve things going forth. I think I am going to post this thread's link into one of the pinned forum topics so we have access to your ideas at a later time.
Thanks!
Rob
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An interesting thing about this station is that it looks much worse than average wear under the worst conditions, it may have been obliterated intentionally. Especially ugly for a Bench, mounted either vertically or horizontally. My guess it was vandalized at some point or other.
Though many USGS stations were submitted to the NGS for inclusion in the NSRS (National Spatial Reference System) most are not. The USGS does not have a public database, and they do not update or upgrade their field monument data in ways that the NGS does, so the likelihood of this mark being a part of a database than needs updated is hard to say. If anything, there may be a PID somewhere in the Database with a Not Found listed, and it will be forever.
Rob
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Jabba,
You found a station set by the USDI NPS, US Department of the Interior, National Park Service.
It is established to mark a location or elevation or both. Likely as a part of a traverse to mark the trail. They can be set at regular intervals or at specific elevations or at points that match a change of contour or direction. It all depends what the criteria for performing the survey was. Sometimes they are set at locations a GIS manager wants them placed, then the type or types of data from that location is collected and added to the GIS. Then they could go back to that known location as a starting place and carry forth further survey from there. For all we could know, each of the marks could have data ascribed in many ways. They are just keeping control data on their respective area is all. It is just another survey mark... It is not part of the NGS database.
Rob
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Harry,
A Landmark Station is the only kind that the NGS will consider removing from the database as destroyed.
The Onus is on you to unequivocally prove it. A Photo that shows the NGS the direction you are facing with the street sign in the intersection will help. They should be able to read the street sign in question in one of the photos. It may take a series of photos to accomplish this. then write the email making your case. There are also websites that offer satellite photography. It is safe to say that if you offered proof from a source like that, showing the coordinates and cross street showing no antenna, then offered the URL to the site so they can see for themselves, that would help too. It makes a strong case. Getting back to the Onus, They will want to check the proof you offer so using things that they can easily check are helpful to them. Once you feel you have a good case, Resize the photos to less than 100 k in size, 4x6 at 72- 100dpi is a nice size, email it to deb.brown@noaa.gov She will look it all over with others in the office Maybe they have enough info to decide, and you see it disappear from the database.
Rob
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Hey All,
This is one of those rare occasions that the USGS set a Triangulation Station. Please note that this disc is the usual thing you see with mention of Bench Mark and other elevation markings. But it also says Pennsylvania on it. These State named stations are not found too often. It is in a Marble post. The Post Measures 33 inches long, 6 inches by 6 inches square. This was a common average size among settings. Frost heave could have been a factor as to why it has appears to have come up out of the ground, it also may have been erosion, but by not being there on location, it would be difficult for me to evaluate that. As mentioned, there was to have been rocks placed around this station that may have been since moved.
The NGS Datasheet says the is a third order horizontal station, It should be within 1-3 inches of perfect, horizontally. There is only Scaled Bench Marked elevation for this station. It was never Leveled. Also rare for USGS stations.
The argument for using the same display format as the NGS datasheet is a good one here, let's look at the the comparisons.
NAD 83(1995)- 40 27 52.12331(N) 079 45 13.96293(W) ADJUSTED (NGS Datasheet)
ddd.mm.sssss format
I convert this to: 40 27.8687218333 079 45.2327155 in dd.mm.mmmmm Format
Minutes + (Seconds / 60)
This compares favorably to GPSr waypoint captures on location of: N 40° 27.869 W 079° 45.233 As taken by Red Shoe & The Navigator.
The GC.com site has N 40° 27.869 W 079° 45.233 (NAD 83)
Altitude: 1362
Coordinates may not be exact. Altitude is SCALED and location is ADJUSTED
It is of course very easy to verify the datasheet and the GPSr set to NAD 83 and ddd.mm.sssss mode right at the location when the settings are alike and we are there. With a good GPS constellation, and hopefully WAAS, if there is nothing else within 5-15 feet you are Money, That's buttah. On the Nut! Dead Nuts even! Close enough for who it's for, I'm Talkin' Yeah baby! And right then and there the data compares in black and white, favorably with the datasheet. You immediately know for sure.
I know a lot of people like to use the geocaching Data, but GC has converted it to a different format from the Original Source. Their conversion also rounds off some of the accuracy. Sorry, but it does. I know Palm Pilots are cool, but I like the datasheet, there is a lot more information on that sheet you will like knowing once you learn about reading it better, like if there are ref marks, azimuth marks and the bearings and distances to them (in meters, multiply by 0.3048 to convert to feet), other nearby stations etc... And you can write notes, draw pictures, even scribble on the back. Push come to shove you can use them to help start a camp fire. Your campfire results may vary with the palm pilot.
Converting the format after the fact is not as fun and you have two different numbers to look at in different formats which are the same place but don't compare and.... Ugh. It can kinda leave us wondering sometimes. Always using the same format with the most accuracy
Triangulation Station Lat & Lon which is adjusted, taken from the datasheet should be more accurate than your GPS can reveal. If they do not compare favorably when in the similar modes, you have either an error in the data or the wrong station. Something worth investigating further.
There was no mention of a Cairn in this description, and how do the Coordinates for the stacked rocks compare with the datasheet? That could help rule out the rockpile... Given all we have to go on, I would say you bagged your station.
Rob
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Something to think about,
1869 was a time when we did not know as much about geomagnetism as we now do.
If you had a calibrated compass alignment area in your yard it could be as simple as 2 4x4's set at points truly north and south in your yard, You could call it a meridian because it is a line, if extended that truly points at the poles of the earth. You would not need to know what the declination for your area is to calibrate your compass, instead you would just go out to your "true Meridian" and orient your compass to north. You would immediately see your declination, and you would take note of that so you would not get off course because of declination. While we call these calibration devices a "True Meridian" they don't have to be aligned to lines on any map or fall on lines of full latitude.
Today we know a lot more about Geomagnetism and we have other ways of aligning ourselves to North. North being the standardized direction for survey azimuths. http://www.ngdc.noaa.gov/seg/geomag/geomag.shtml is a site we can use to calibrate our compass to a true north azimuth, given any geomagnetic declination no matter where in the country we are, and without the use of an established meridian.
For surveying, it was found that performing survey with a compass is a difficult thing to maintain, as declination is not stable. Not for any location when taken over time. Things we do with compass today, would become inaccurate not long after. It begged a question all too often, "how can descriptions for things remain stable if declination is not stable", further, since declination is only correct in a specific place, moving very far from that specific place created errors. It simply is not consistent enough to use for exacting work. Today, PLSS work is based off polar azimuths or geodetic azimuths, rather than magnetic for obvious reasons, and it is likely the reason that the rest of the NJ court houses never bothered to finish their meridians. They became a moot methodology as we found better ways of doing things with higher quality methods and instrumentation.
Going forth, it is easy to see why many states that became states later on, did not adopt this practice.
This is a great Link for looking over all the reasoning behind this. Follow the links at the bottom of the page for more interesting reading.
Enjoy!
Rob
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Maps
in Benchmarking
Hank,
This website may be a useful resource to you: http://www.geocommunicator.gov/GeoComm/lsi...home/index.html
You may have some luck visiting your County Courthouse. The civil engineers, treasurer or tax collectors may have paper copies you can purchase.
Good Luck!
Rob
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Coolclay,
You made a great point of interest in the imagining what the world was like back then. It was not easy work and this particular station reveals that really well. In 1855, imagine the difficulty experienced in drilling holes in rock... By Hand! The first methods for commercially refining steel from iron were discovered in 1855. The drill they used was very unlikely to be steel. The earthen cone is consistent with the find of a different soil type found when the station was re dug. They did not say earthenware cone, but I had a sense that later surveyors were looking for signs of the pottery which was not there. To be honest, many of the types of Mathematical equations being used in geodesy were still being developed and refined in 1855. The Clarke Ellipsoid, since superseded, which became part of many of these equations was still 11 years away. Many of the instruments used to measure all this were still in development as well, yet they were the best ones in existence. Even in 1929, automobiles were not exactly up for this kind of terrain and a horse and buggy may have been the best vehicle to transport the many heavy things to the top of a hill. Did Concrete come in redimix bags then? No Kidding!
Sulfur is a dry powdery element at environmental temperatures which is lemon yellow in color and is not soluble in water. It packs well and so it is a great way to help define a drill hole as a marker especially when you consider 1855 as a bit pre industrial. You have a bag of this stuff handy and you have a bright yellow frame of reference that should stay put a good long time provided there is not too much disturbance in the area, and the theory proved itself well. The alternative is to allow the drill hole to fill with dirt, and they would have... A harder thing to find in that state.
This station is a great story of how technology and methods change and improve an exacting science, as well as the perspectives that different professionals can bring to a given set of circumstances. Thanks for sharing that!
Rob
Lots Of Questions!!
in Benchmarking
Posted · Edited by evenfall
Graveyard Mom,
A couple things that may help make sense of all this and answer a bunch of questions, are the FAQ Page, and this Link started by the 2oldfarts. There are a lot of answers to the questions you have on both those links.
Oh and regarding the did not find reports in the NGS logs. Well, your milage may vary. The quality of the reports of not found can vary, some agencies can be better than others, and even the NGS can be skunked. If you are up to it, feel free to have a go at them yourself. Some times they really are gone, sometimes just hidden really well, sometimes the description isn't very useful and sometimes we get lucky. I have hunted a few stations that took time and a lot of thinking to find. I had one, which I had easily found that I went back to re-photo a year later and it took 10 minutes to find. The only difference? The year before the renter of the property kept up their yard and it was in plain sight. The new renter was not quite as fastidious. I knew where it was but until I got down and started combing through the grass by hand, I could not see it. It was completely obscured. You can imagine what I was thinking, I knew for sure it was there, I even knew where to look. It still took 10 minutes to find in that grass, only one year later. I couldn't believe it myself. I can assure you that that station which was super easy in a mowed lawn will have been a did not find for all who would not have bothered to look very hard in the taller grass.
Enjoy and Happy Thanksgiving,
Rob