[GRASS-user] i.landsat.toar comments have only 0 value

[Nikos Alexandris]

On Friday 30 of August 2013 02:56:14 Beatrice wrote:

> Dear All,

Good Day Beatrice,

 
> I have been running i.landsat.toar but have just noted this problem. For me
> it shows zeros both in the command output (verbose) and output metadata
> (r.info). An example for one of the bands:

 
> From command output:
> 
>  LANDSAT: 5 SENSOR: TM
>  ACQUISITION DATE 2011-07-05 [production date 2011-11-29]
>    Earth-sun distance    = 0.00000000
>    Solar elevation angle = 0.00000000
>    Atmospheric correction = dos4
>    Percent of solar irradiance in path radiance = 0.0000
> -------------------
>  BAND 1  (code 1)
>    calibrated digital number (DN): 0.0 to 0.0
>    calibration constants (L): 0.000 to 0.000
>    at-surface radiance = 0.00000000 * DN + -0.000
>    mean solar exoatmospheric irradiance (ESUN): -0.000
>    at-surface reflectance = radiance / 0.00000
>    the darkness DN with a least 1000 pixels is 1
>    the DN mode is 53
> -------------------


> From r.info for the same band:
>  |     Earth-sun distance (d) ................ -0.00000000
>  |     
>  |     Digital number (DN) range ............. 0 to 0
>  |     
>  |     Calibration constants (Lmin to Lmax) .. +0.000 to +0.000
>  |     
>  |     DN to Radiance (gain and bias) ........ +0.00000 and +0.00000
>  |     
>  |     Mean solar irradiance (ESUN) .......... 0.000
>  |     
>  |     Reflectance = Radiance divided by ..... 0.00000
>  |     
>  |     
>  |     
>  |     Dark object (1000 pixels) DN = ........ 1
>  |     
>  |     Mode in reflectance histogram ......... 0.00000


This doesn't look healthy.  However, I think it is a past problem which is 
fixed.

 
> Running i.landsat.toar -p results to
> 
> number=5
> creation=2011-11-29
> date=2011-07-05
> sun_elev=45.585310
> sensor=TM
> bands=7
> sunaz=44.259879
> 
> Which I think confirms that i.landsat.toar can read input values from my
> metafile. The output bands have values in the range of surface
> reflectance/temperature (for band 6). For example
> 
> Band 1 output - Range of data:    min = 0.01  max = 0.461925184292249, Data
> Units:   unitless
> Band 2 output - Range of data:    min = 0.01  max = 0.925906812458597, Data
> Units:   unitless
> Band 3 output - Range of data:    min = 0.01  max = 0.785829845850446, Data
> Units:   unitless
> .
> .
> Band 6 output - Range of data:    min = 203.371307953013  max =
> 327.669907753679, Data Units:   Kelvin
> 
> I have same results when using MTL or MTLOld as source of metadata, on TM or
> ETM+ sensors and different atmospheric correction methods (uncorrected,
> DOS). I am running winGRASS7 revision 57466.
> 
> Is there a problem with the printed output from r.info/command output or are
> these zeros the actual values that i.landsat.toar uses as input to
> computations?

I doubt that r.info has a problem reading the metadata that pertain to a 
queried raster map.  If I am not wrong, it merely reads simple text files that 
reside inside the "hist" directory inside the corresponding Mapset.

My guess is that you use an older version of i.landsat.toar whicj, indeed, 
produces empty raster maps.  Unfortunately, I do not use (nor have any access 
to a Windows machine) so as to be in position to help directly.  We need 
feedback from someone with a Windows OS.

(
On/Off-Topic:  is there a way to run and test GRASS in an emulated Windows 
environment for those who don't have a legally licensed Windows OS?
)

Best, Nikos