[postgis-users] St_Area to acres

[Nathan Gerber]

In looking at EPSG:26986 on spatialreference.org (
http://spatialreference.org/ref/epsg/26986/ ) it appears that the
projection's native units are meters rather than feet. If you divide
by 4046.85642 (number of square meters in an acre) your acreage numbers
will come out much closer than they are at present but will still be a bit
off.
--
Nathan Gerber


On Mon, Jul 9, 2012 at 11:44 PM, Daniel Cole <daniel at southernsolutionsms.com
> wrote:

> I am using the code below:
>
> *Select name, acreage, ST_Area(ST_Transform(geom, 26986))/43560 as acres
> from ss.fields*
>
> and getting these results.
>
>
> name acreageacres H 01
> 15.79
> 1.50398045317257
> H 02
> 29.02
> 2.76480120804097
> H 03
> 31.95
> 3.04337512685165
> H 04
> 34.71
> 3.30710750534269
> H 05
> 111.6
> 10.6322788992474
>
>
>
> I have another program where I am importing the acreage data from and I
> just wanted it to match up in postgis well in case I ever wanted to
> calculate it myself.  It seems that I am almost there, but I am a decimal
> off and I can't understand that.
>
> Also I am not very familiar with the 26986, but I used it because I saw it
> used for sqare feet somewhere else.  Should I be using anything else?
>
> Thanks,
>
> DC
>
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