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<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial>Richard,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial>Are you points in longitude, latitude. If they are the
best place to start might be using the geography type. This requires using
PostGIS 1.5+</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff><A
href="http://www.postgis.org/documentation/manual-1.5SVN/ch04.html#PostGIS_Geography">http://www.postgis.org/documentation/manual-1.5SVN/ch04.html#PostGIS_Geography</A></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial>You can also read the free chapter of our book which covers
this in some detail.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff
size=2 face=Arial></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=640442405-04042011><FONT color=#0000ff><A
href="http://www.postgis.us/chapter_01">http://www.postgis.us/chapter_01</A></FONT></SPAN></DIV>
<DIV><FONT color=#0000ff size=2 face=Arial></FONT> </DIV>
<DIV><SPAN class=640442405-04042011><FONT color=#0000ff size=2
face=Arial>Leo</FONT></SPAN></DIV>
<DIV><SPAN class=640442405-04042011><FONT color=#0000ff size=2 face=Arial><A
href="http://www.postgis.us">http://www.postgis.us</A></FONT></SPAN></DIV>
<DIV><SPAN class=640442405-04042011><FONT color=#0000ff size=2
face=Arial></FONT></SPAN> </DIV>
<DIV><BR></DIV>
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<FONT size=2 face=Tahoma><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of
</B>Richard Gomes<BR><B>Sent:</B> Monday, April 04, 2011 12:46 AM<BR><B>To:</B>
postgis-users@postgis.refractions.net<BR><B>Subject:</B> [postgis-users]
Converting meters to another unit<BR></FONT><BR></DIV>
<DIV></DIV><FONT face=sans-serif>Hi All,<BR><BR>I'm a newbie on PostGIS and GIS
in general.<BR><BR>Reading section "Taking Advantages of Indexes"
at<BR> <A class=moz-txt-link-freetext
href="http://postgis.refractions.net/docs/ch04.html#id2638955">http://postgis.refractions.net/docs/ch04.html#id2638955</A><BR><BR>...
I became confused regarding how I could retrieve points which are distant up to
500 meters from a given point.<BR>The question is actually how I can transform
500 meters onto some some other figure on a unit I don't understand very well
what it is about. I need this calculation in order to determine a Box3d like the
article suggests.<BR><BR>Thanks a lot and regards,<BR></FONT><FONT
face=sans-serif><BR></FONT>-- <BR><PRE class=moz-signature cols="72">Richard Gomes
</PRE></BODY></HTML>