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Scaled coordinates off by 185 miles

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I noticed that the listed coordinates for a benchmark in my area, SW1616, are a bit...off.


Based on the datasheet description it's located in Marysville, WA here in Snohomish County.


But the coordinates:


NAD 83(1986)- 47 24 16. (N) 118 19 53. (W) SCALED


Would put it SE from Marysville by 185 miles and on the other end of the state.




Any advice on how to get this corrected?


I haven't tried to find it yet, but hopefully will get out that way soon for an attempt.





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Incorrect scaled coordinates (and heights) are unfortunately not entirely uncommon in the NGS database. As these were all scaled and entered into the database by hand some 20+ years ago so we find these from time-to-time. Thanks for reporting this. I will review this when I get into the office tomorrow and forward a change notice to the NGS database team.

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Wow! I get excited when I can correct coordinates which are in error by 185 feet. But 185 miles is awesome!


In addition to DaveD' adjustment, see if you can get a decent GPS reading at the site. If so, it can be entered as a Waypoint when logging on GEOCACHING.COM, and as "HH2 Coordinates" if you log at NGS.


A professional surveyor who posts to this Forum has a method of changing Scaled coordinates to HH2 coordinates on the NGS data sheet. Prior to seeing Dave's response, I was going to recommend sending your GPS reading to that individual. And it still can be done, although it may not be necessary after Dave does his magic. :rolleyes:



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The correct scaled coordinates are 48-05-59, 122-10-32. If anyone would like to send their hand-held values for scaled marks to update the NGS database, you can send them to me at dave.doyle@noaa.gov. I will require the PID, station designation and the latitude and longitude to 1 decimal place if your hand-held does not have WAAS or some other correction, and is therefore good to +/- 10 m, and 2 decimal places if you are using WAAS or some other correction service to get to the +/- 3 m range. I would appreciate this information in an Excel spreadsheet. I typically send an update file to our database once ever quarter.

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And if you get to the neighborhood of the wrong coordinates, see if you can find a disk there. I haven't looked in the data base to see what is near there. Sometimes these mixups are more complicated than just a random error in one entry.


Edit: compare SW0197 Designation H 70. It is at the "wrong" coordinates for SW1616 Designation H 7 70 RESET. That's where they probably got the coordinates. Elevation given is much different, so the reset info was probably right, just the staff grabbed the wrong designation to copy the coords from.


The corrected coordinates DaveD gave match up with TR0177 Designation 70 with a ToReach description very similar to SW1616 and its stamping said 1909, as does the reset SW1616. So TR0177 was the mark that got reset, and somewhere along the way the designation and/or stamping got confused.

Edited by Bill93
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