BuckBrooke
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Posts posted by BuckBrooke
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Greetings, all.
Here's a fun story about a lighthouse (probably an intersection station) that disappeared for quite a while, then reappeared in an unexpected place:
http://www.cnn.com/2008/US/06/04/lighthous...d.ap/index.html
My guess is that the lighthouse in reference (moved in 1925 from the CNN article) might have been LW3802 BILLINGSGATE LIGHTHOUSE, or there's a slim chance it might have been LW3804 BILLINGSGATE LIGHTHOUSE (1932 C&GS log makes it unlikely), though it could have been some other light house in the area.
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Harry, I've found a couple like yours, along I-25 and I-40 around Albuquerque. The whole concrete monument is up and laying on its side, usually tumbled down a hill due to erosion of the bank, or dug out of the ground along the ROW fence by a fiber optic company laying fiber. Officially DESTROYED in both sorts of situations.
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As a wild conjecture, possibly an inexperienced CCC surveyor during the Depression?
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Followup questions/comments:
1. The surveyor is a very confident person, but he still uses a personal opinion about the questioned stone.
2. He used GPS from other points known on the neighboring properties to locate his designated position.
3. The positions he used were 2000 to 4000 feet away and one was from the bottom of a cliff.
4. The positions he found on the neighboring properties originated from range lines from the old King land grants.
5. The deeds all the way back to the early 1800s all refer to name of neighbors and do not have and proper measurements listed on the deeds.
6. I do thing you're right to get a second opinion.
7. The entire area around the questioned location is forest land.
8. The only map I found that makes reference to a stone in that area, is a 1938 blister pine rust map, without any other exact details.
9. Either location would work fine, but I am a stickler for detail and I think if the found stone was the designated location for the past two hundred years, then that it should stay the same.
10. If the stone was not the boundary mark, then the new location would be fine.
11. Is there any web sites that might have pictures of old monuments to use as a guide?
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Greetings.
I received an email from a member of the general public in New Hampshire, with a question about surveying his property. Not knowing enough to advise him, he's agreed to letting me post the question/situation here for commentary. Thoughts?
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I have found what looks to me to be the original stone marker on the corner of my 50 acre property in New Hampshire.
The surveyor did not give it much thought and tells me he has plotted the actual corner some 30 feet away.
Back in the old days they could have been off by the 30 foot angle, so the question is how do I determine the actual corner.
Use his location or use what I think is the historic location?
The stone is squared on top and tapered outward toward the bottom.
It also looks hand chiseled.
There is another smaller squared piece that looks like it could have once been part of the larger stone.
The visible length of one piece is approx 12-14 long the other is 8-10 and i think there may be more of it deeper in the ground.
The property has not been surveyed in the past 100 years that I know of.
What would you suggest to determine the actual historic location, or would you just go by the surveyors new set post?
I would prefer to use the historic location if I can be absolutely sure of its original setting.
The surveyor has just received his licence in the past two years.
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Bill, that must be a heck of a flashlight, or an extremely sensitive compass. I'd have thought there's not enough metals, and certainly not high enough generated magnetic fields to move a compass needle. Doesn't seem to work with my 4D maglight and compass just now. Interesting.
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I've recently (the past year) begun daily commuting between Albuquerque, NM and Socorro, NM, about an hour and 5 minutes drive (80 miles). I had long ago recovered (or not ) all of the PIDs along that stretch of I-25. The New Mexico Highway Commission placed a line of disks, a line of can/rods and a line of small steel I-beams (not PIDs, but sticking up about 4-6 inches) along the route in the 1970s/1980s, and given the info to the NGS. No one had logged them since then. I've been very pleased to see survey crews work their way along a stretch of the highway, using and tagging the marks there.
In particular, in one several mile stretch a landowner terraced a series of fields along one side of the highway, and had hired surveyors to make the field flat. I watched them use the thirty year old benchmarks I logged to do so. Kind of fun to know what's going on, when most driving by wouldn't.
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I've always liked the benchmarks placed here in NM that have a gnomon in the center and markings so the photo of the disk also tells the time of day and day of the year.
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The descriptions/ties for the quads for my area that I've received in the past are often extremely terse, as noted above, especially for older marks. Echo to most everyone else's comments.
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tightcoyote,
Greetings, and interesting find. I haven't seen a photo of a US Engineer Department - Tulsa District disk before. Mind if I add it to the agency list, available here:
www.unm.edu/~creelbm/pages/agencies.html
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Computer hiccup.
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My goal is to update the NGS databse with useful information. If a station has been recovered recently (2-3 years) I generally don't update unless I can add more information about the station.
That being said, travel, illness and commuting 2 hrs/day for my dissertation has really knocked the fun out of weekend benchmarking. I've a few dream weeklong benchmarking vacations lined up for when I graduate, but I don't think it'll happen.
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atari52oo, the quick answer is that Geocaching would have to go through a lot of work to update their version of the NGS database. The Geocaching version was uploaded from CDs from the last time (2001) that the NGS offered its database for purchase on CDs.
The NGS no longer offers their database in CDs, and I would imagine it's not useful for the NGS to go through the effort to make a new CD version (everyone has internet access and can get to the source directly). Geocaching has pretty much said it's not interested in going through the hassle of interfacing to the NGS website for a small community of its users.
In reality, for many stations the Geocaching site is more up to date, in terms of active logs. Whether they're accurate or not, that's another story.
Reasons why an update from the NGS database would be a lot of trouble for not much benefit, in order of size/significance:
1) As GEOCAC is the largest group responsible for logs in the last year or two on the NGS' database, the updated log changes wouldn't be that different. According to the stats that holograph keeps, GEOCAC has had 25,500 logs on the NGS database since the community formed on Geocaching when the geocaching.com/mark went live in 2001. I'd imagine that there are that many or less logs from other agencies in the same time period, or less (this has been discussed somewhere). As geocaching.com/mark shows 90,000 stations logged, I'd bet a fair number of the 65,000 remaining updates on Geocaching overlap with the ones updated on the NGS database, so the gap is probably much smaller than 25,000 stations (3.5% of the database).
2) There aren't a zillion disks that have been added to the NGS database since 2001, probably < 10,000, and concentrated in relatively few areas/projects, so there wouldn't be that many new disks for that many folks.
3) As for the handfuls (< a couple hundred?) of odd/quirky stations that fell through the cracks the first time, Geocaching doesn't have time to hand edit those back in.
The Geocaching.com/mark version of the database seriously dumbs down the information for the community, and so it serves a different purpose for us. A subset of our community wants to go through the extra steps and rigor to work with/log on the NGS database; I think most Geocachers, and a good chunk of benchmarkers, are willing to live with some of the quirks of the Geocaching version.
We probably should put some version of this discussion in the FAQ if it's not there already.
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I've run across 4 or 5 New Mexico Highway Commission disks whose monuments had tumbled down from eroded highway cuts. I took photos and contacted Deb to have it destroyed on the NGS end of things, and contacted the New Mexico Highway Department for their end. I actually got a response, and approval, from the head of the surveying section of the NMHD, which was unexpected.
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Doc Geo, I think you have the right disks, but I would email Deb Brown at the NGS. Odds are what 68-eldo said, and the datasheet adds a confusing note by saying the year stamped on the disk is 1966. Too bad there's no MARK_LOGO. I'd bet it's the right station, and there was just some confusion when entering it into the system.
There's a chance that the NGS might not have found the USC&GS 1943 disk in 1966, and remonumented, but I really doubt it.
Edit: Oh, see BDT's more authoritative comment in the NGS category, yesterday.
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I'm going to try to get an update today.
Doc, on your photo for the NGS Vertical Control Mark variant, because the disk is partially covered I'm having a tough time picking out variant details. What did you notice?
BDT's initial suggestions for the list were for disk type markers; at one point the NGS folks were putting together a photo page to show all the types. We'll see if that's in their website update.
The Texas disk is new; thanks!
The USGS pipecap is listed under USGS - Corner Station. Perhaps I should indicate it's a pipecap. Also, the BM0534 disk is a USC&GS Triangulation Station disk, also listed.
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I agree with Renegade. The only object I know of for "traffic barrel" is what he pictured. I bet there used to be a row of barrels on that spur of concrete, to help guide traffic, because of the odd intersections there. Especially in Klemmer's overhead view, there might have been a symmetric line of barrels on the spur in the NW corner of the picture. They might have only been there for a short period of time, maybe only during construction?
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Greetings, CasualObserver; I've been to the overlook I think you're talking about. Typically, anytime you see a disk without a clear agency name, and that has 3 letters, you're looking at a local surveyor's mark w/ their initials. My guess is that WR AP 1 is White Rock A(?) Park, and this is the first disk in the series put down there when the park was created, which would fit with the 1964 date. It's called Overlook Park, but perhaps it was named something else before then.
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Hey, Deb. Thanks for the update, and the hard work.
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BDT, no I can't do Cepheids. That would be sweet. There are two optical parallax satellite missions coming out in the next decade, GAIA and SIM, that should be able to get optical parallaxes to some Cepheids.
I'm using maser emission of water, frequency 22GHz/wavelength ~1cm. Essentially, it's a one pass astrophysical laser where water in a cloud on the line of sight is in the high energy state, and a passing photon with the right energy spontaneously kicks it down to the lower state, emitting the same photon again in the same direction. Now you've got 2, soon 4, etc. and soon you have a whole lot of light coming down a narrow beam. Thus, we can see them across the galaxy/into other galaxies.
However, very few stars, mostly young early types and late evolved types, have this emission. I'm working with proto-planetary nebulae (or pre-planetary), which are a late type evolved star, and am looking to do this with a small set of planetary nebulae which have the water maser emission. For those not in the know, this is the parallax measurement, pretty much what I'm doing, same instrument:
http://www.nrao.edu/pr/2007/starfmparallax/
except that they're working on the birth end of stars.
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Thanks, everybody; I'll try to put them in this weekend. I'm not spending as much time on benchmarking as I used to, as I got a fellowship to finish my dissertation and am commuting 160 miles/day (80 each way). Kind of takes the fun out of driving on the weekends. Also, my days are longer.
As a fun note, I'm making images of bipolar jet flows coming out of evolved stars. Tip to tip on the lobes of the stars is 350 milli-arcseconds with pixel size of at worst 100 micro-arcseconds. I should be able to measure parallaxes in the next year of 50 uas with 5 sigma accuracay (all the way across the galaxy).
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Ole did pretty well, getting within 1/3 of 1%.
My understanding of the USC&GS experiment is that have a triangle of three accurately surveyed positions, thus you know the distance between them. If you then send pulsed radio signals from two points, and receive them at the third, and calculate the path lengths, you should be able to compare that to your known distance to determine how fast the pulses took. Shoran uses hyperbolic paths, etc. so it's a little more complicated, but if your control network is long enough, and you do enough measurements, you will see any discrepancy in the speed of light show up. The error in the published speed of light that he detected was something like one foot in four miles.
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Geo*, LORAN has been used for a long time, and also came out of the WWII radar work, but the measurements of the speed of light were done with SHORAN, not LORAN.
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Greetings, all. I thought you might find this interesting. Let's see if Dave D. runs across this post.
This is an excerpt from a book I'm casually reading by Louis Brown, "A Radar History of World War II: Technical and Military Imperatives" 1999.
Chapter 10: The Measure of Radar
10.1 Navigation Transformed
10.1.5 Radio Navigation and the velocity of light
Shoran was a hyperbolic-coordinate navigation system that used the same principles as Gee-H but with an automatic pilot's direction indicator. It had an on-board computer allowing a continuous presentation of the data that permitted blind bombing. It proved to have the accuracy of Oboe or visual bombing but with each bomber capable of using it independently. It was introduced into combat in April 1945 and consequently had little effect on the course of the war[17].
The US Coast and Geodetic Survey learned of the accuracies suspected of the various radio-navigation systems and wished to evaluate this new method of measuring the Earth. With the Army Air Forces they set up as a test, Shoran ground stations at locations where there was surveyed control. The results showed precision of two parts in a million but systematic discrepancies from the control data of 50 parts per million, which could be effectively removed if the velocity of light was altered from the accepted value[18].
The tabulated value in 1941 was 299,776 +/- 4 km/s. This had resulted primarily from extensive measurements initiated by A A Michelson and carried to completion after his death by his assistants. The experiments had used long, evacuated paths and incorporated what was thought to be the ultimate in experimental accuracy[19]. It was significantly lower than Michelson's previous value, and the experimental uncertainties ascribed each measurement made them incompatible one with the other. Any warning provided by this was swept aside by a confirmation experiment at Harvard that used the Kerr-cell light switch rather than Michelson's rotating mirror and that allowed electronic timing. The result was 299,764 +/- 15 km/s[20]. The Coast and Geodetic Survey found that a value of 299,792 +/- 2.4 km/s made their Shoran data compatible with their ground-surveyd data, very near Michelson's older value.
William Hansen had proposed to use a resonating cavity to measure the velocity of light. By knowing the frequency at which the cavity resonated, its dimensions and the rate of its power dissipation, one could calculate the velocity of the waves. This experiment had been carried out at the National Physical Laboratories in England before the Shoran experiment, and gave 299,793 +/- 9 km/s [21], a value also significantly in disagreement with the then accepted value. Other confirmations of the new value were to follow with microwaves and light. The laser was eventually to take accuracy to the currently accepted value of 299,792.458 +/- 0.0012 km/s, but for a time the blue ribbon belonged to microwaves.
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[17] Henry E Guerlac Radar in World War II New Yoprk: Tomash-American Institute of Physics Publishers, 1987. pp 525-529
[18] Carl I Aslakson, Velocity of Electromagnetic Waves Nature Vol 164, pp 711-712, 1949
[19] A A Michelson, F G Pease and F Pearson, Measurement of the Velocity of Light in a Partial Vacuum Ap. J. VOl 82, pp 26-61, 1935
[20] Wilmer C Anderson Rev. Sci. Inst. Vol 8, pp 239-247, 1937
[21] L Essen, Velocity of Electromagnetic Waves Nature Vol 159, pp 611-612, 1947
I tried to get the USC&GS Nature article from 1949, but they've only scanned their articles back to 1950 (darn it). There's a 1951 article as well, but I can't get to it from home.
Here's an NGS article with excerpts from Aslakson's memoir. He's a pretty cool character.
Buckner Creel Survey Mark Web Site
in Benchmarking
Posted
Hey, folks. I'm moving that info over to my new website, www.gnomons.org I have the agency list up and running, more or less.