<div dir="ltr"><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">Hi,</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">
I'm newbie in GRASS GIS and image processing. I want to produce NDVI maps from Landsat 8 imagery. I try to convert Landsat 8 DN to ToAR by using i.landsat.toar module in GRASS GIS v7.0.svn - on Windows 8 x64 platform.</div>
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<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">The conversion parameters (Earth-Sun distance, sun elevation, DN range, gain and bias and etc.) are all reported as 0 (zero) in metadata of resulting ToAR maps (I've added one of the metadata generated by <a href="http://r.info" target="_blank">r.info</a> at the end of my message). </div>
<div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">Another issue during the conversion process, i.landsat.toar module warn that </div>
<div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<font face="courier new, monospace" color="#0000ff">ESUN evaluated from REFLECTANCE_MAXIMUM_BAND<div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small;display:inline"> </div></font><span style="font-family:tahoma,sans-serif">???</span></blockquote>
<div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">r.report stats:<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">
<br></div><div class="gmail_default"><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><font color="#0000ff"><font face="courier new, monospace">n: 10403<br>
</font><font face="courier new, monospace">minimum: 0.0227376<br></font><font face="courier new, monospace">maximum: 0.587083</font></font></blockquote></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">
<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">Is there a problem in 'DN to ToAR conversion' in GRASS GIS 7.0? </div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">
How to resolve this issue? And my last question is: Can I trust these results obtained by i.landsat.toar?</div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">
<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small">Best regards,<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><hr color="#CC0017" align="left" size="1" width="100%" style="font-family:'Times New Roman';font-size:medium">
<span style="font-family:'Segoe UI',Arial,sans-serif;font-size:9pt;font-weight:bold"><span style="color:rgb(204,0,23)">Dr. Hasan Sarptaş</span><br></span><div style="font-family:'Times New Roman';font-size:medium">
<span style="font-family:'Segoe UI',Arial,sans-serif;font-size:9pt"></span></div><div style="font-family:'Times New Roman';font-size:medium"><span style="font-family:'Segoe UI',Arial,sans-serif;font-size:9pt"><font color="#666666"><span style="color:rgb(68,68,68)"></span><br>
Ege University</font></span></div><div style="font-family:'Times New Roman';font-size:medium"><span style="font-family:'Segoe UI',Arial,sans-serif;font-size:9pt"><font color="#666666">Solar Energy Institute<br>
</font></span></div><div style="font-family:'Times New Roman';font-size:medium"><span style="font-family:'Segoe UI',Arial,sans-serif;font-size:9pt"><font color="#666666">Energy Tech.<br></font></span></div>
<div style="font-family:'Times New Roman';font-size:medium"><span style="color:rgb(102,102,102);font-family:'Segoe UI',Arial,sans-serif;font-size:9pt">İzmir, TURKEY.<br></span></div><div style="font-family:'Times New Roman';font-size:medium">
<font color="#666666" face="Segoe UI, Arial, sans-serif" style="font-size:small"><span style="font-size:12px">me: </span></font><a href="http://about.me/sarptas" style="font-size:12px;font-family:'Segoe UI',Arial,sans-serif" target="_blank">http://about.me/sarptas</a></div>
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<br></div><div class="gmail_default" style="font-family:tahoma,sans-serif;font-size:small"><br></div><div class="gmail_default"><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)">(Wed Jan 22 02:49:22 2014) </font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"><a href="http://r.info" target="_blank">r.info</a> map=ToA_Ref_4@Landsat </font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> +----------------------------------------------------------------------------+</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Layer: ToA_Ref_4@Landsat Date: Wed Jan 22 02:41:47 2014 |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Mapset: Landsat Login of Creator: Hasan |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Location: Ege |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | DataBase: C:\Users\Hasan\Documents\GIS DataBase\Landsat8 |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Title: ( ToA_Ref_4 ) |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Timestamp: none |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> |----------------------------------------------------------------------------|</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Type of Map: raster Number of Categories: -0 |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Data Type: DCELL |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Data Units: unitless Vertical datum: (none) |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Rows: 7811 |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Columns: 7671 |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Total Cells: 59918181 |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Projection: UTM (zone </font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)">) |</font></div>
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<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | N: 4423515 S: 4189185 Res: 30 |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | E: 716115 W: 485985 Res: 30 |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Range of data: min = 0.0154847031183999 max = 2.65962954976276 |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Data Description: |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | generated by i.landsat.toar |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Comments: |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Reflectance of Landsat-8 OLI/TIRS (method uncorrected) |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | ----------------------------------------------------------------- |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Acquisition date (and time) ........... 2013-12-05 (-0.0000 h) |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Production date ....................... 2013-12-05 |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Earth-sun distance (d) ................ -</font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0.0000000</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Sun elevation (and azimuth) ........... </font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">-0.00000 (0.00000)</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> |</font></div>
<div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Digital number (DN) range ............. </font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0 to 0</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Calibration constants (Lmin to Lmax) .. -24740000909121687407621537690 |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | DN to Radiance (gain and bias) ........ +</font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0.00000</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> and +</font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0.00</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)">000 |</font></div>
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<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Mean solar irradiance (ESUN) .......... </font><font face="courier new, monospace" style="background-color:rgb(255,255,0)">0.000</font><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | Radiance to Reflectance (divide by) ... +0.00000 |</font></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | ------------------------------------------------------------------ |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | i.landsat.toar input_prefix="LC81800332013339LGN00_B" output_prefix=\ |</font></div>
<div class="gmail_default"><span style="background-color:rgb(238,238,238)"><font face="courier new, monospace"> | "ToA_Ref_</font></span><span style="background-color:rgb(238,238,238);font-family:'courier new',monospace">LC81800332013339LGN00_B</span><font face="courier new, monospace">" metfile="</font><span style="font-family:'courier new',monospace">LC81800332013339LGN00_MTL.txt" sensor="oli8" met\ |</span></div>
<div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | hod="uncorrected" percent=0.01 pixel=1000 rayleigh=0.0 |</font></div><div class="gmail_default">
<font face="courier new, monospace" style="background-color:rgb(238,238,238)"> | |</font></div><div class="gmail_default"><font face="courier new, monospace" style="background-color:rgb(238,238,238)"> +----------------------------------------------------------------------------+</font></div>
<div class="gmail_default"><font face="courier new, monospace"><span style="background-color:rgb(238,238,238)">(Wed Jan 22 02:49:23 2014) Command finished (0 sec) </span> </font></div></div>
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