<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:13px"><div id="yui_3_16_0_1_1434012154766_7636"><span id="yui_3_16_0_1_1434012154766_7895">Dear Grass community,</span></div><div id="yui_3_16_0_1_1434012154766_7680"><br><span></span></div><div id="yui_3_16_0_1_1434012154766_7683" dir="ltr"><span id="yui_3_16_0_1_1434012154766_7682">our objective is to monitor the soil moisture index (SMI) of small catchments in Mali and the impact of irrigation structures. <br></span></div><div id="yui_3_16_0_1_1434012154766_7707" dir="ltr"><span id="yui_3_16_0_1_1434012154766_7682">We have taken note of the many articles on this subject and as it looks now we can utilize the huge Landsat archive available on the web. <br></span></div><div id="yui_3_16_0_1_1434012154766_7740" dir="ltr"><span id="yui_3_16_0_1_1434012154766_7682">With the Landsat bands and the GRASS modules we're able to produce rasters for the surface temperature and for the NDVI values. To determine th SMI value it's necessary to do a regression analyses (the so called 'wet edge' and 'dry edge' in a scatter plot between the two mentioned rasters. How can we achieve this? <br></span></div><div id="yui_3_16_0_1_1434012154766_7875" dir="ltr"><br><span id="yui_3_16_0_1_1434012154766_7682"></span></div><div id="yui_3_16_0_1_1434012154766_7893" dir="ltr"><span id="yui_3_16_0_1_1434012154766_7682">Thanks</span></div><div id="yui_3_16_0_1_1434012154766_7634"> </div><div id="yui_3_16_0_1_1434012154766_7626" class="signature"><font id="yui_3_16_0_1_1434012154766_7625" class="Apple-style-span" face="arial, helvetica, sans-serif" size="2"><font id="yui_3_13_0_1_1396344566582_10784" face="Arial" size="1"><span id="yui_3_13_0_1_1396344566582_10783" style="font-size:7.5pt;font-family:arial;" lang="EN-GB">Huub Munstege<br></span></font><font id="yui_3_16_0_1_1434012154766_7878" size="1">Bamako <br>Rép. du Mali</font><br><br><br><br><br></font><hr id="yui_3_16_0_1_1434012154766_7752" style="width:100%;height:2px;"></div></div></body></html>