[OSGeo-Discuss] Nomination period closing soon...

2007-05-31 Thread Tyler Mitchell (OSGeo CRO)
As a follow up to: http://lists.osgeo.org/pipermail/discuss/2007-May/001964.html I am just reminding you that you have 3 more days to submit nominations for new Charter Members for OSGeo. See above URL for more information. Please send to: [EMAIL PROTECTED] and include a clear reason for

[OSGeo-Discuss] OSGeo Brasil List created

2007-05-31 Thread Paulo Marcondes
Hi All, follows the first post and announcement message sent to various lists regarding the creation of the list. As I know there are some portuguese speakers here that aren't on other lists. So Here it goes (in portuguese) Also, non brazilians, but otherwise portuguese speakers are invited. BTW

Re: [OSGeo-Discuss] Computing area using different Spatial Refences

2007-05-31 Thread Paulo Marcondes
2007/5/31, Eduardo Patto Kanegae <[EMAIL PROTECTED]>: For a given geometry(described at the end of message), we calculated values using "to UTM WGS84" and "to UTM SAD69" and have different values. - Hectares using Transform(...,29183) = 30,9977784638335 - Hectares using Transform(...,32723) = 3

Re: [OSGeo-Discuss] Computing area using different Spatial Refences

2007-05-31 Thread Eduardo Patto Kanegae
Thanks Steve. I forgot to THINK before writing. :-) With this error sizing for a milion of hectares, just 6 hectares will be the difference. best Eduardo Stephen Woodbridge wrote: Wouldn't you want to use an equiarea projection to calculate the area? or are these small enough that is does n

Re: [OSGeo-Discuss] Computing area using different Spatial Refences

2007-05-31 Thread Stephen Woodbridge
Wouldn't you want to use an equiarea projection to calculate the area? or are these small enough that is does not matter. I would expect some numerical rounding error, does this difference fall into that? All questions, no answers today :) -Steve W Eduardo Patto Kanegae wrote: Hi folks, A c

[OSGeo-Discuss] Computing area using different Spatial Refences

2007-05-31 Thread Eduardo Patto Kanegae
Hi folks, A cartographic doubt: We have a WGS 84 dataset ( EPSG:4326 ) and the need to to calculate (in hectares) the area of each polygon. To do this, we are currently transforming these objects for our local common UTM spatial reference ( SAD69, EPSG:29183 ) . But, I was thinking if maybe th