Hello all, I am using i.atcorr module of GRASS 7.0.4 release. I compiled the release, as I wanted to add the Sentinel-2 sensor. So far, I was successful in compiling the release. However, when I run atcorr, I get an empty raster file. I have included the reports from r.info, i.atcorr and the parameters below:
*r.info <http://r.info> output of the image* (Wed Mar 16 16:38:39 2016) r.info map=S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32TPS_B02@PERMANENT +----------------------------------------------------------------------------+ | Map: S2A_OPER_MSI_L1C_TL_EPA__2016 Date: Wed Mar 16 16:29:33 2016 | | Mapset: PERMANENT Login of Creator: abheeman | | Location: munich | | DataBase: /media/abheeman/data/grassdata | | Title: ( S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32TPS_B02 ) | | Timestamp: none | |----------------------------------------------------------------------------| | | | Type of Map: raster Number of Categories: 0 | | Data Type: CELL | | Rows: 10980 | | Columns: 10980 | | Total Cells: 120560400 | | Projection: UTM (zone 32) | | N: 5200020 S: 5090220 Res: 10 | | E: 709800 W: 600000 Res: 10 | | Range of data: min = 0 max = *23562* | | | | Data Description: | | generated by r.in.gdal | | | | Comments: | | r.in.gdal -e input="/media/abheeman/data/grassdata/S2A_OPER_PRD_MSIL\ | | 1C_PDMC_20160315T115050_R065_V20150826T102655_20150826T102655.SAFE/G\ | | RANULE/S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32TPS_N02.0\ | | 1/IMG_DATA/S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32TPS_B\ | | 02.jp2" output="S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32\ | | TPS_B02" memory=300 offset=0 | | | +----------------------------------------------------------------------------+ (Wed Mar 16 16:38:39 2016) Command finished (0 sec) *i.atcorr verbose return* (Wed Mar 16 16:39:48 2016) i.atcorr -i -r --overwrite --verbose input=S2A_OPER_MSI_L1C_TL_EPA__20160315T065417_A000920_T32TPS_B02@PERMANENT range=0,10000 parameters=/media/abheeman/data/grassdata/conf output=munich_test_atcorr * ****************************** 6s version 4.2b ****************************** * * geometrical conditions identity * * ------------------------------- * * Sentinel 2 observation * * * * month: 8 day: 26 * * solar zenith angle: 39.16 deg solar azimuthal angle: 161.21 deg * * view zenith angle: 0.00 deg view azimuthal angle:0.00 deg * * scattering angle: 140.84 deg azimuthal angle difference: 161.21 deg * * * * atmospheric model description * * ----------------------------- * * atmospheric model identity : * * tropical (uh2o=4.12g/cm2,uo3=.247cm-atm) * * * * aerosols type identity : * * Continental aerosols model * * * * optical condition identity : * * visibility : 13.00 km opt. thick. 550nm: 0.3516 * * * * spectral condition * * ------------------ * * sentinel_2 band1 * * value of filter function : * * wl inf= 0.300 mic wl sup= 2.600mic * * * * target type * * ----------- * * homogeneous ground * * constant reflectance over the spectra 0.000 * * * * target elevation description * * ---------------------------- * * ground pressure [mb] 954.77 * * ground altitude [km] 0.520 * * gaseous content at target level: * * uh2o= 3.227 g/cm2 uo3= 0.246 cm-atm * * * * atmospheric correction activated * * -------------------------------- * Atmospheric correction... Atmospheric correction complete. (Wed Mar 16 16:39:59 2016) Command finished (10 sec) *Parameters used* 20 - geometrical conditions=Sentinel-2 08 26 10.48 11.353693 48.200905 - month day hh.ddd longitude latitude ("hh.ddd" is in decimal hours GMT) 1 - atmospheric mode=tropical 1 - aerosols model=continental 13 - visibility [km] (aerosol model concentration) -0.520 - mean target elevation above sea level [km] (here 600m asl) -786 - sensor height (here, sensor on board a satellite) 129 - 1nd band of Sentinel-2A *Note* Before I invest more time in finding process to derive correct AOT and chose appropriate atmospheric model, I wanted to give it a try with fake parameters. As far as I understand, with fake parameter there should be some short of false atmospheric correction. Therefore, there are false values for atmospheric mode, aerosol model and visibility just for test purpose. *From r.info <http://r.info>, maximum value seems to be 23562. But the value in sentinel bands can range only between 0-10000 currently, which brings to the assumption that it probably could be noise. Will it affect the result?* *Some general questions:* 1. *For 6s parameter, it take geographic coordinate (I guess EPSG:4326) as input. So, I was wondering if we also have transform the coordinate system of the image to the same?* 2. *In my system, it took 10 seconds to process one image. But, I am not sure if the processing time will remain same when the process outputs non-empty file. My image size is 10980x10980 pixels. What is general processing time it generally takes, for may be single Landsat-8 image ?* 3. *Regarding the raster with empty output, does anybody have experienced such behavior recently? The discussions I searched mostly date back to the time when Landsat-8 was not supported.* If it helps, I am running grass in the computer with Ubuntu 14.04 system, with 8 cores,16 gb ram and Intel Core i7-4790. Regards, Abhishek
_______________________________________________ grass-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/grass-user
