[GRASS-user] i.landsat.toar fails to convert DNs (bands 61 and 62) to temperature for Landsat 7 scene

[Nikos Alexandris]

Hi list(s).

While  i.landsat.toar  works just fine with all bands in converting DNs to 
Radiance/Reflectance (with some method=dos?), it seems, at least in once case 
(scene LE71840312002041SGS00), it fails to convert bands 61 and 62 in 
temperature!

Same happens (as described below in both G64 and G70).
Can anyone confirm or reject?

Best, Nikos


# within a MAPSET that contains only bands pertaining to a scene
g.region rast=B1 && r.info -r B1

min=0
max=255

# temperatures (DNs) 61
r.info -r B61

min=0
max=231

# DNs 62
r.info -r B62

min=0
max=255

# rest of bands look fine!

# convert
i.landsat.toar --o input_prefix=B output_prefix=B.DOS1.ToCR. 
metfile=LE71840312002041SGS00_MTL.txt method=dos1

Calculating dark pixel of <B1>...
Calculating dark pixel of <B2>...
...
..
.
Writing reflectance of <B7> to <B.DOS1.ToCR.7>...
 100%
Writing reflectance of <B8> to <B.DOS1.ToCR.8>...
 100%

# querying
r.info -r B.DOS1.ToCR.1

min=1.66812525243449e-05
max=0.633957421717228

# temperature from 61
r.info -r B.DOS1.ToCR.61
min=-nan
max=-nan

# from 62
r.info -r B.DOS1.ToCR.62
min=-nan
max=-nan

# rest of bands look fine!

# complete r.info for 61
+----------------------------------------------------------------------------+
| Layer:    B.DOS1.ToCR.61                 Date: Thu Feb 14 15:09:22 2013    |
| Mapset:   LE71840312002041SGS00          Login of Creator: nik             |
| Location: wgs84_utm_z34_test                                               |
| DataBase: /geo/grassdb/ellas                                               |
| Title:     ( B.DOS1.ToCR.61 )                                              |
| Timestamp: none                                                            |
|----------------------------------------------------------------------------|
|                                                                            |
|   Type of Map:  raster               Number of Categories: 255             |
|   Data Type:    DCELL                                                      |
|   Data Units:   Kelvin               Vertical datum:                       |
|   Rows:         7141                                                       |
|   Columns:      7871                                                       |
|   Total Cells:  56206811                                                   |
|        Projection: UTM (zone 34)                                           |
|            N:    4732815    S:    4518585   Res:    30                     |
|            E:     774315    W:     538185   Res:    30                     |
|   Range of data:    min = -nan  max = -nan                                 |
|                                                                            |
|   Data Description:                                                        |
|    generated by i.landsat.toar                                             |
|                                                                            |
|   Comments:                                                                |
|     Temperature of Landsat-7 ETM+ (method dos1)                            |
|    ----------------------------------------------------------------        |
|     Acquisition date ...................... 2002-02-10                     |
|     Production date ....................... 2013-01-14                     |
|                                                                            |
|     Earth-sun distance (d) ................ 0.98679702                     |
|     Digital number (DN) range ............. 0 to 0                         |
|     Calibration constants (Lmin to Lmax) .. +0.000 to +0.000               |
|     DN to Radiance (gain and bias) ........ -nan and -nan                  |
|     Temperature (K1 and K2) ............... 666.090 and 1282.710           |
|    -----------------------------------------------------------------       |
|                                                                            |
|    i.landsat.toar input_prefix="B" output_prefix="B.DOS1.ToCR." metfile\   |
|    ="LE71840312002041SGS00_MTL.txt" method="dos1" perce\   |
|    nt=0.01 pixel=1000 rayleigh=0.0                                         |
|                                                                            |
+----------------------------------------------------------------------------+