I don't know how many hundreds of Caltrans acquisition deeds I've read over the years, but in all that time I've never needed to pay attention to the coordinates given. Today I'm trying to fit a deed to the ground, at least approximately, and all I have so far are the coordinates. However, they aren't making sense to me.
The deed dates from 1965, and cites "California State Zone 2 Coordinates X=2,067,271.34 and Y=430,463.68." It subsequently states that the coordinates are on the "California Coordinate System, Zone 2." Distances, and presumably coordinates, are in feet. Given the date of the deed, I assumed these to be NAD27 values (they're definitely not NAD83 values). However, when I convert to geographic using CORPSCON, I come out 20 or so miles north of the intended location. I hand-cranked it using Special Pub 253 and came up with the same result.
Is there an implementation of CCS27 that I'm not aware of, or some other custom system that Caltrans used back in the day?
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Caltrans 60's-Era Coordinates
- Jim Frame
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dmi
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Surveyor826
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Transposition?
Y=340,463.68 vs Y=430,463.68
moves it 17 miles south.
My experience with those coordinates is that they are worse than useless.
They imply a precision to the uninitiated that was never intended by originator and will never be found by the resurveyor.
If its all you've got then I suppose you'll have to do something with them, just saying I would diligently search for something better (or maybe I mean more reliable).
Good Luck!
moves it 17 miles south.
My experience with those coordinates is that they are worse than useless.
They imply a precision to the uninitiated that was never intended by originator and will never be found by the resurveyor.
If its all you've got then I suppose you'll have to do something with them, just saying I would diligently search for something better (or maybe I mean more reliable).
Good Luck!
- land butcher
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They are definitely in feet, we didn't use metric when I was there in the late 60's early 70s. What you might try doing is just inversing between the coords and use the bearings and distances. A ground to grid adj should not be that hard to find data on, but IIRC under 5 miles the difference isn't much unless you are 3000ft above sea level.
Another thing to remember is that CDH would scale a distance and call it out xxxx.00ft and base everything in the area on that. So adjoining legs to x.xx are +/- who knows how much.
Another thing to remember is that CDH would scale a distance and call it out xxxx.00ft and base everything in the area on that. So adjoining legs to x.xx are +/- who knows how much.
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bruce hall
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maybe if you
use what you think the approx NAD83 coord should be, then work back to the stuff that Cal Trans has, maybe a transpostion will show up, which when "corrected" will put you in the right place.
Bruce Hall Land Surveyor No. 4743
5732 Middlecoff Drive
Huntington Beach, Ca. 92649
714 840 4380
5732 Middlecoff Drive
Huntington Beach, Ca. 92649
714 840 4380
- Jim Frame
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The problem is that the deed is tied to the A2 line (the old highway centerline), but the ROW and monumentation maps only show ties to the A3 line (the current freeway centerline). The A2 line is shown on the maps graphically, but there's no mathematical tie between them.
I've got the deed positioned approximately for now, but absent information relating A2 to A3, I'm in a bind.
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I've got the deed positioned approximately for now, but absent information relating A2 to A3, I'm in a bind.
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- land butcher
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