<br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">yes thanks, that looks great. The man page does not talk about it beyond<br>
a filename in the example, but does it need to be processed with<br>
i.landsat.toar before running i.landsat.acca? i.e. does it want derived<br>
temperatures instead of raw DNs? With DNs it exits with an error that it<br>
wants DCELL maps. (if temp, probably FCELL would be ok too, as the<br>
instrument is not that precise)<br></blockquote><div><br>as mentionned in the description.html, i.landsat.acca work with reflectance and temperature, so you have to use i.landsat.toar before i.landsat.acca <br><br></div>
<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
how do the i.landsat.acca, i.landsat.dehaze, and i.landsat.toar addon<br>
modules fit in/overlap with the i.atcorr module?<br></blockquote><div><br>i.lansdat.dehaze make just a "light" athmospheric correction<br>i.attcorr do atmospheric correction using the 6S algorythm wich is much more efficient, but need some extra parameters, and also work with several type of capters<br>
so you have to use i.landsat.dehaze OR i.attcorr <br><br>i.landsat.toar convert DN to radiance/reflectance and temparature<br>i.landsat.acca compute a cloud mask<br><br><br><blockquote style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;" class="gmail_quote">
also the acca man page does not really explain what benefit the 2-pass<br>
mode gives and what the -f flag does. ?<br></blockquote><br>i think you can find all the explanations you can need about the way it's working on the dedicated paper:<br>Irish R.R., Barker J.L., Goward S.N., and Arvidson T., 2006. Characterization of the Landsat-7 ETM+ Automated Cloud-Cover Assessment (ACCA) Algorithm. Photogrammetric Engineering and Remote Sensing vol. 72(10): 1179-1188<br>
<a href="http://www.asprs.org/publications/pers/2006journal/october/2006_oct_1179-1188.pdf">http://www.asprs.org/publications/pers/2006journal/october/2006_oct_1179-1188.pdf</a><br><br><br>regards,<br>Sylvain<br></div></div>