Talk:Willamette Stone

Location

What are the (equator-based) latitude and (Greenwich-based) longitude coordinates of this marker? —Preceding unsigned comment added by 216.47.188.16 (talk) 20:27, 8 September 2008 (UTC)

Look at the upper-right of the article—where it says "coordinates". That is a clickable URL which provides a jump off to many mapping services with that coordinate. —EncMstr (talk) 20:33, 8 September 2008 (UTC)

Unfortunatly, the coordinates are off. Google earth has a picture of the marker, 310 feet to the west, and 45 feet to the south. I dont have a GPS to use at the site, but will visit it next spring. ( triangulation lists it as 359 feet, 8.5 inches away. )

BUT to answer the question: The Latitude of the marker is 45° 31′ 10.83″ N and the longitude of the marker 122° 44′ 33.55″ W ( according to the article...) —Preceding unsigned comment added by 67.174.157.126 (talk) 22:35, 19 November 2008 (UTC)

Probably the reason the coordinates are off is that there was a datum change in 1983, changing from NAD27 to NAD83. This mostly affected the longitude, but a little the latitude as well. The following seems like a competently done survey: https://www.plso.org/Resources/Documents/PLSOJuneJuly2009_web.pdf As stated on Page 16: "Okay, so, I’ve got to let the cat out of the bag. All of you surveyors out there must be wondering, “Come on Greg, just exactly where is the Willamette Stone?” Latitude 45°31'10.23551" North, Longitude 122°44'37.89866" West. The elevation is only published to the nearest foot, so that should settle the positional reliability issue, at least vertically, for all of you “least squares” jar heads." Allassa37 (talk) 20:52, 20 March 2021 (UTC)

Source for expansion/citations

• this might have useful info to integrate. Aboutmovies (talk) 08:56, 5 October 2008 (UTC)

More coord/location questions

Does anyone know where the coords given on the page came from? This BLM page says lat 45-31-11 and long 122-44-34. I've seen different numbers given elsewhere--mostly in rather old sources. As I look into principal meridians I am seeing that the coords given in earlier times were likely off, with modern surveying, GPS, etc, providing better precision and accuracy. As a result sources are likely to differ over the coords. As I understand it though, even if a principal meridian was defined as, say, 122-44-34 longitude, if it later was discovered that the survey monuments placed on the ground were not exactly on that longitude it did not mean that the legally defined meridian (and all derived range and township lines, real property lines, etc) were shifted on the ground. Rather the precise location of the monuments, baselines, meridians, etc, were found to have slightly different coordinates than previously thought. This would make it slightly tricky to describe on a page like this. Perhaps something could be said about this aspect of land surveying and examples given of the coords determined by early surveys compared to more recent coords? I'm not sure, just thinking out loud. I'd like to make a new page about the Willamette Meridian specifically, if I find the time. For now I'm mainly curious about where the coords given on this page came from. Anyone know? (perhaps when coords are added to a page the source ought to be mentioned in a comment or something--can't footnote a coord template...) Pfly (talk) 21:26, 3 October 2009 (UTC)

It was added here and the coordinate value hasn't changed, though it's been repositioned in the article. However, there's no explanation of the source. —EncMstr (talk) 17:10, 4 October 2009 (UTC)

Ah, thanks. I've realized that the lat/long coords don't actually matter much because the entire land survey grid for Oregon and Washington is based on the physical location of the Willamette Stone, not its actual lat/long. Land parcels are specified by reference to the stone, not lat/long numbers. I'm slowly building a page for the Willamette Meridian and will try to describe this somewhat counter-intuitive aspect of the land survey system. I had been thinking the lat/long coords of the stone were vital because all real estate is based on it, but as it turns out the lat/long is essentially irrelevant--except in letting people know where to find the stone! So I guess it would be best to use the most accurate and up-to-date coords available. Google Earth is probably perfectly fine. Anyway, just thinking out loud. Pfly (talk) 17:23, 4 October 2009 (UTC)

It'd be entirely OR, but I'd be happy to drop by with a GPS and get you very exact coordinates. I've found that most published coordinates are off by a bit- several signs and a monument at the equator, signs at the Arctic Circle, and more. tedder (talk) 19:19, 4 October 2009 (UTC)

There's one web page, Principal Meridian Project, that gives coords based on people visiting with GPS, and looking at Google Earth--for a number of PLSS points of origin. They give 45 31 10.24 N, 122 44 37.90 W for the Willamette Stone. I'm sure the site would not do as a RS under the scrutiny of something like a feature class review, but it could be useful on a less than perfect page (or perhaps count as reliable if explained that recent "unofficial" GPS readings give such-and-such coords. The best "official" coords I have seen date to something like 1972 and use degree-minute-second precision (with who knows what accuracy). So...sure, if you felt so inclined you could see how well your reading compares with those of the pmproject people. —Preceding unsigned comment added by Pfly (talk • contribs) 21:35, 4 October 2009 (UTC)

Okay, I used the GPS coords to update it. Obviously, there are more WP:Vish ways to do it, but it's better than what was there previously (by 298 feet). It also matches the PMP measurements to within 17 feet, which is actually the error my GPS calculated. So perhaps their OR is better than my OR. = tedder (talk) 01:46, 15 October 2009 (UTC)

Ah, thanks! Heh, WP:Vish. If nothing else better coords on this page will help in making Wikipedia placemarks more useful in things like Google Maps, Earth, and other web mapping apps that use WP coord data. I began to work on a Willamette Meridian page but got sidetracked and probably won't manage to finish for a while. I did get the book Chaining Oregon though. It's pretty good, if somewhat dry and limited in scope (sadly, it doesn't appear to get into the (offset) principal meridians used in eastern and southwestern Oregon). So far the main impression is--those surveyors worked hard, but their previous experience surveying in the Midwest did not prepare them for the mountains of Oregon. They chose the site of the Willamette Stone such that the meridian would pass west of Vancouver Lake and that the baseline would not cross the Columbia River. But they apparently did not realize that the in working south the meridian drifted east of the main Willamette Valley, into the foothills of the Cascades. Pfly (talk) 08:16, 15 October 2009 (UTC)

Source

• https://oregonencyclopedia.org/articles/willamette_stone_and_willamette_meridian/#.WT_22RiZNo4 ---Another Believer _(Talk) 14:30, 13 June 2017 (UTC)

Datum shifted between NAD27 and NAD83 in 1983

In 1983, the North American Datum shifted from the prior NAD27 (1927) to NAD83 (1983), see: https://en.wikipedia.org/wiki/North_American_Datum At the position of the Willamette Stone, the shift would have changed measured GPS values by about 95 meters, about 300 feet. (mostly in changed longitude, a much smaller amount in changed latitude.) https://en.wikipedia.org/wiki/North_American_Datum#/media/File:Datum_Shift_Between_NAD27_and_NAD83.png This probably explains a lot of the confusion as to the varying Lat/Lon values we have seen. The article should be re-written to explain to lay people why the GPS values differ between the pre-1983 published values, and what they currently see if they use their smartphones and a GPS app. Also, within the last 2 years, some newer smartphones have begun using dual-frequency GPS signals, employing both L1 and L5 signals, which are dramatically more accurate than L1-only, single frequency GPS recivers previously employed. https://insidegnss.com/galileo-hits-the-spot-testing-gnss-dual-frequency-with-smartphones/ I just bought one. I think this article should include the best-known Lat/Lon for the Stone based on the current NAD83. I will go to the Stone and record the GPS value and post it here on this Talk Page. Sure, you can call that original research (OR), and yes, it should shortly be augmented with an 'official', published value. But perhaps that measured value will help us identify which published value is likely to be the correct one. Aside: Google search is great for finding text. But in this specific case, what we could use is a search that is 'GPS-aware', or at least 'number-aware': Suppose we are looking for a GPS coordinate which we believe to be "lat 45-31-11 and long 122-44-34" (values arbitrarily taken from a comment above.). What we'd like to find is some value published on the Internet which is 'close to' that coordinate, but successfully find it even if the numerical values in the last few digits of the number are slightly off. An additional confusing factor is that GPS coordinates can be displayed as DDD.dddddd, or DDD MM.mmmm, or DDD MM SS.sss. (D=degree, M=minute, S=second). Does anyone know if there is a mechanism for finding what might be the 'correct' value? Allassa37 (talk) 22:17, 12 March 2021 (UTC)

Okay, I have gone to the Willamette Stone, and used a dual-frequency GPS smartphone, plus the app Precision GPS, to measure the Lat/Lon of the stone. The averaging clock time was about 10 minutes and 30 seconds. The result was: 45 degrees, 31 minutes, 10.3407 seconds North, -122 degrees, 44 minutes, 38.1621 seconds West. What is the resolution? I believe that one minute of arc of latitude is 6,000 feet, so one second of arc is 100 feet, and a hundredth of a second of arc is 1 foot. As for longitude, those values are approximately multiplied by 1/(Square Root 2), so a minute of distance at about 45 degrees is (6000 feet/1.414), or 4,243 feet, one second is 4,243/60 = 70.7 feet, and a hundredth of a second is 0.707 feet, or about 8.5 inches. This site https://www.lat-long.com/Latitude-Longitude-1952647-Oregon-Willamette_Stone.html shows some values: Degrees Minutes Seconds: Latitude: 45-31'10 N Longitude: 122-44'37 W Decimal Degrees: Latitude: 45.5195621 Longitude: -122.7437089 It appears that the figure for decimal degrees more-precisely states the value. I will convert the decimal degrees of latitude to minutes and seconds, by first multiplying the portion after the decimal point by 60: 0.5195621 x 60 = 31.173726. And multiplying 0.173726 x 60 = 10.42356 Or: 122 degrees, 31 minutes, 10.42356. However, the precision justified by those 7 digits past the "Decimal" degrees, 7 digits, only seems to justify about 1/3000 of a second of arc resolution. Similarly, for the longitude, multiplying 0.7437089 by 60 results in: 44.622534. Multiplying 0.622534 x 60 results in: 37.35204. Or, 122 degrees, 44 minutes, and 37.35204 seconds. Similarly, only 1/3000 after the seconds decimal point is justified, or about 37.3520 seconds. Allassa37 (talk) 06:54, 19 March 2021 (UTC)

This seems like a competently done survey: https://www.plso.org/Resources/Documents/PLSOJuneJuly2009_web.pdf As stated on Page 16: "Okay, so, I’ve got to let the cat out of the bag. All of you surveyors out there must be wondering, “Come on Greg, just exactly where is the Willamette Stone?” Latitude 45°31'10.23551" North, Longitude 122°44'37.89866" West. The elevation is only published to the nearest foot, so that should settle the positional reliability issue, at least vertically, for all of you “least squares” jar heads." Allassa37 (talk) 06:54, 19 March 2021 (UTC)

"Willamette Stone and Willamette Meridian" listed at Redirects for discussion

A discussion is taking place to address the redirect Willamette Stone and Willamette Meridian. The discussion will occur at Wikipedia:Redirects for discussion/Log/2021 November 19#Willamette Stone and Willamette Meridian until a consensus is reached, and readers of this page are welcome to contribute to the discussion. Mdewman6 (talk) 19:36, 19 November 2021 (UTC)