[GRASS-user] Estimating Albedo from Landsat

[Hamish]

Hamish:
> Probably we should concentrate on the North Carolina
> dataset for common tests... its landsat mapset has:
...
> lsat7_2000_10
> lsat7_2000_20
> lsat7_2000_30
> lsat7_2000_40
> lsat7_2000_50
> lsat7_2000_61
> lsat7_2000_70
> lsat7_2000_80
> 
> metadata from hist/ file:
> SPACECRAFT_ID=Landsat7,SENSOR_ID=ETM+,ACQUISITION_DATE=2000-03-31,WRS_P
> ATH=16,CPF_FILE_NAME=L7CPF20000101_20000331_12,LMAX_BAND1=191.600,LMIN_
> BAND1=-6.200,LMAX_BAND2=196.500,LMIN_BAND2=-6.400,LMAX_BAND3=152.900,LM
> IN_BAND3=-5.000,LMAX_BAND4=241.100,LMIN_BAND4=-5.100,LMAX_BAND5=31.060,
> LMIN_BAND5=-1.000,LMAX_BAND61=17.040,LMIN_BAND61=0.000,LMAX_BAND62=12.6
> 50,LMIN_BAND62=3.200,LMAX_BAND7=10.800,LMIN_BAND7=-0.350,LMAX_BAND8=243
> .100,LMIN_BAND8=-4.700,QCALMAX_BAND1=255.0,QCALMIN_BAND1=1.0,QCALMAX_BA
> ND2=255.0,QCALMIN_BAND2=1.0,QCALMAX_BAND3=255.0,QCALMIN_BAND3=1.0,QCALM
> AX_BAND4=255.0,QCALMIN_BAND4=1.0,QCALMAX_BAND5=255.0,QCALMIN_BAND5=1.0,
> QCALMAX_BAND61=255.0,QCALMIN_BAND61=1.0,QCALMAX_BAND62=255.0,QCALMIN_BA
> ND62=1.0,QCALMAX_BAND7=255.0,QCALMIN_BAND7=1.0,QCALMAX_BAND8=255.0,QCAL
> MIN_BAND8=1.0,SUN_AZIMUTH=139.6033279,SUN_ELEVATION=51.524652
> 

GRASS> i.landsat.toar band=lsat7_2000 sensor=7 date=2000-03-31 product_date=2000-07-02 -v solar_elevation=51.524652 gain=HHHLHLHHL

production date and gains are based on above coeffs & examining the book
values.

GRASS> i.landsat.acca lsat7_2000.toar -2fs out=lsat7_2000.clouds

looks a bit over enthusiastic in the output map.

The stats line looks reasonable--   Cloud cover :  3.332 %

but output mask shows 66% of cells as clouds:
G65> r.stats lsat5_1987.clouds -pl
6 Cold cloud  62.96%
9 Warm cloud   3.07%
* no data  33.97%

?!

(fwiw, I've had very good results using i.landsat.acca with landsat7 over
water, except for high thin cirrus clouds, but it's known those are missed)


Auto-cloud determination for the NC 1987 Landsat5 scene is no good.



Hamish