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<DIV><FONT face=Arial color=#0000ff size=2><SPAN class=911510722-28092004>I'm
getting degrees^2 because my geometry is in lat/lon afaict.</SPAN></FONT></DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=911510722-28092004></SPAN></FONT> </DIV>
<DIV><FONT face=Arial color=#0000ff size=2><SPAN
class=911510722-28092004>-e</SPAN></FONT></DIV>
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<DIV></DIV>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left><FONT
face=Tahoma size=2>-----Original Message-----<BR><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of
</B>Craig Miller<BR><B>Sent:</B> Tuesday, September 28, 2004 4:07
PM<BR><B>To:</B> 'PostGIS Users Discussion'<BR><B>Subject:</B> RE:
[postgis-users] Computing area in km^2 from 4326
geometries<BR><BR></FONT></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">If the area function
is returning square meters (depends on your projection) then just divide the
answer by 4046.896 to get kilometers.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">All area functions
are squared by definition.<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">--Craig<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<DIV>
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face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR tabIndex=-1 align=center width="100%" SIZE=2>
</SPAN></FONT></DIV>
<P class=MsoNormal><B><FONT face=Tahoma size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</SPAN></FONT></B><FONT
face=Tahoma size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> Ethan
Alpert [mailto:ealpert@digitalglobe.com] <BR><B><SPAN
style="FONT-WEIGHT: bold">Sent:</SPAN></B> Tuesday, September 28, 2004 2:57
PM<BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> PostGIS Users
Discussion<BR><B><SPAN style="FONT-WEIGHT: bold">Subject:</SPAN></B>
[postgis-users] Computing area in km^2 from 4326
geometries</SPAN></FONT><o:p></o:p></P></DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"><o:p> </o:p></SPAN></FONT></P>
<DIV>
<P class=MsoNormal><FONT face=Arial color=blue size=2><SPAN lang=DE
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">How does one compute
areas in km^2? I was thinking something like
area2d(transform(the_geom,<someEPSG>)). </SPAN></FONT><SPAN
lang=DE><o:p></o:p></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><FONT face=Arial color=blue size=2><SPAN lang=DE
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">How do others do
this?</SPAN></FONT><SPAN lang=DE><o:p></o:p></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN lang=DE
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><FONT face=Arial color=blue size=2><SPAN lang=DE
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Thanks!</SPAN></FONT><SPAN
lang=DE><o:p></o:p></SPAN></P></DIV>
<DIV>
<P class=MsoNormal><FONT face="Times New Roman" size=3><SPAN lang=DE
style="FONT-SIZE: 12pt"> <o:p></o:p></SPAN></FONT></P></DIV>
<DIV>
<P class=MsoNormal><FONT face=Arial color=blue size=2><SPAN lang=DE
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">-e</SPAN></FONT><SPAN
lang=DE><o:p></o:p></SPAN></P></DIV></DIV></BLOCKQUOTE></BODY></HTML>