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<p>I have a question - this didn't seem to be an issue until 2.18.12
QGIS. I'm currently on 2.18.13 Ubuntu 17.04. I could be missing
something. <br>
</p>
<p>I have a forestry client and they were preparing to do some
aerial spraying. So I outlined the area to be sprayed and
generated acres. Generally I set my project properties to feet
(for units) and square feet (for area) and the ellipsoid set to
none/planimetric. My data is stored in WGS84 in postgis. I pulled
it out into a shapefile and eventually stored it in geopackage
while trying to track down my issue.<br>
</p>
<p>Dropbox link to the data:
<a class="moz-txt-link-freetext"
href="https://www.dropbox.com/sh/8w1spcxu5by7z70/AACilL5kOeOC7tzX4WCEkOdka?dl=0">https://www.dropbox.com/sh/8w1spcxu5by7z70/AACilL5kOeOC7tzX4WCEkOdka?dl=0</a></p>
<p>I set the CRS to EPSG:2274 - the data is in wgs84. <br>
</p>
<p>If I run acres with project properties set to feet, square feet,
and none/planimetric and using the Field Calculator I get: 372.82
acres. This is wrong. <br>
</p>
<p>If I run acres with project properties set to feet, square feet,
and wgs84 as the ellipsoid I get 307.41 acres which appears to be
right. <br>
</p>
<p>If I run acres using the virtual layer abilities: <i>select
sum(st_area(st_transform(geometry,2274))/43560) from spray</i> I
get 306.04 acres which may be right. <br>
</p>
<p>I didn't notice this until 2.18.12 - I updated to 2.18.13 and it
is still acting "odd" - I didn't notice in 2.18.11 but I'm not
sure if I ran any area calculations in 2.18.11. I have also
noticed that if I switch from wgs84 (feet, square feet, none for
ellipsoid in the project properties) and then switch to EPSG:2274
the ellipsoid changes to grs1980(iugg 1980)...... which having the
ellipsoid at GRS80 may have been covering for my area calculations
and making them "about right". <br>
</p>
<p>Anyway thoughts? Ideas? Am I doing something wrong?<br>
</p>
<p>Randy<br>
</p>
<p><br>
</p>
<p> <br>
</p>
<pre class="moz-signature" cols="72"> --
Randal Hale
North River Geographic Systems, Inc
<a class="moz-txt-link-abbreviated" href="mailto:rjhale@northrivergeographic.com">rjhale@northrivergeographic.com</a>
(423) 653-3611
<a class="moz-txt-link-freetext" href="https://www.northrivergeographic.com">https://www.northrivergeographic.com</a></pre>
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