Thank you very much for your assistance. Changing the file names worked, as you suggested. I will now be able to move forward with my image processing.

Thanks again...William

On 09/09/2016 06:12 PM, Nikos Alexandris wrote:

William Hudspeth:

I am using i.worldview.toar with the latest version of GRASS 7.3. I was
able to successfully download and install this extension. I have tried
using the module with the following input and error. All of the input
files exist, and I get an error stating that "No data base element files
found". Help appreciated...

outputsuffix=toar utc=2010-04-11T18:07:06.558405Z doy=101 sea=60.3

Nikos Alexandris:

Do you really need the 'worldview2' prefix for your band names? It's
identical to your Mapset's name. This is what a mapset is meant (or can
be used) for: a set of maps.  In this case, it's a set of 'worldview2'

Would you rename your bands and try again?

i.worldview.toar band=b1_RED,b2_GREEN,b3_BLUE,b4_NIR outputsuffix=toar
utc=2010-04-11T18:07:06.558405Z doy=101 sea=60.3

William Hudspeth:

I have given the bands simpler names, have re-run i.worldview.toar, and
am getting the same error:

outputsuffix=toar utc=2010-04-11T18:07:06.558405Z doy=101 sea=60.3
|! Using Day of Year to calculate Earth-Sun distance.

|! Region matching the b1_red@worldview2 spectral band

|* Processing the b1_red@worldview2 band
Traceback (most recent call last):
"/home/wilbur/.grass7/addons/scripts/i.worldview.toar", line
416, in <module>
"/home/wilbur/.grass7/addons/scripts/i.worldview.toar", line
320, in main
    acf = float(CF_BW_ESUN[band][2])
KeyError: 'b1_red'
WARNING: No data base element files found


apologies for the inconvenience. I now had a better look and remember what is
what. Comments from the code itself:

Factors for Conversion to Top-of-Atmosphere Spectral Radiance
   (absolute radiometric calibration factors)

Structure of the dictionary:
- Key: Name of band
- Items in tupple(s):
   - 1st: Absolute Calibration Factors
   - 2nd: Spectral Band's Effective Bandwidth, Δλ
   - 3rd: Band-Averaged Solar Spectral Irradiance [W/sq.m./micro-m]

Retrieving values:
   band = <Name of Band>
   K[band][0]  # for Effective Bandwidth
   K[band][1]  # for Esun
   K[band][2]  # for Absolute Conversion Factor

which are stored in the following python dictionary:

   'Pan':     (0.28460000, 1580.8140, 0.056783450),
   'Coastal': (0.04730000, 1758.2229, 0.009295654),
   'Blue':    (0.05430000, 1974.2416, 0.012608250),
   'Green':   (0.06300000, 1856.4104, 0.009713071),
   'Yellow':  (0.03740000, 1738.4791, 0.005829815),
   'Red':     (0.05740000, 1559.4555, 0.011036230),
   'RedEdge': (0.03930000, 1342.0695, 0.005188136),
   'NIR1':    (0.09890000, 1069.7302, 0.012243800),
   'NIR2':    (0.09960000,  861.2866, 0.009042234)}

The module is flexible to request for any of the bands to be
converted. Yet, it has the disatvanage that requires the very name(s) of the
corresponding "key(s)" to access the respective calibration factors.

In short, rename your bands to exactly 'Red', 'Green', 'Blue', 'NIR'. Maybe this can be
changed, but I wouldn't have the time at the moment for it.

If you have any changes, already, please make a pull request in the github repository.



*William Hudspeth, PhD, MPH*
Earth Data Analysis Center
MSC01 1110
1 University of New Mexico
Albuquerque, New Mexico 87131-0001
tel: 505-277-3622, ext. 249
grass-user mailing list

Reply via email to