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Message: Re: Possibility of checker for grandfathered polygon based challenge

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Changed By: sumbloke
Change Date: July 15, 2020 03:59AM

Re: Possibility of checker for grandfathered polygon based challenge
I think what vogelbird is saying is that the quads were originally defined in NAD27 datum. If you take those coordinates and map them using WGS84 you will get quadrangles, but they will be in a different location. According to https://gisgeography.com/datum-transformations/ they will be 60-70m off around Salt Lake. So for your Fort Douglas example, the WGS84 coordinates should be (using https://tool-online.com/en/coordinate-converter.php to convert):

"Fort Douglas":{"rect":[40.87288082,40.74788216,-111.875,-111.75]}

Edit: But if you're happy with those inaccuracies, give us the coordinates you have.

Original Message

Author: sumbloke
Date: July 15, 2020 03:56AM

Re: Possibility of checker for grandfathered polygon based challenge
I think what vogelbird is saying is that the quads were originally defined in NAD27 datum. If you take those coordinates and map them using WGS84 you will get quadrangles, but they will be in a different location. According to https://gisgeography.com/datum-transformations/ they will be 60-70m off around Salt Lake. So for your Fort Douglas example, the WGS84 coordinates should be (using https://tool-online.com/en/coordinate-converter.php to convert):

"Fort Douglas":{"rect":[40.87288082,40.74788216,-111.875,-111.75]}