Pete,
Thanks for the help. Actually, I already tried adding parens to the equation,
including the variation you
suggested, but the results are the same. Do you have a few lines of code that
worked for you that you'd
be willing to share? Or, do you recall whether there's any issue with netCDF
auto-scaling the input data,
or any units conversion that has to be included that's not in the
documentation?
Thanks... Art
> From: "Pete Pokrandt" <poker@xxxxxxxxxxxx>
> To: "ARTHUR AUGUST PERSON" <aap1@xxxxxxx>, "ldm-users"
> <ldm-users@xxxxxxxxxxxxxxxx>
> Sent: Friday, January 12, 2018 11:47:08 AM
> Subject: Re: [ldm-users] Problem calculating GOES-16 brightness temperature
> from
> radiance
> Art,
> I think it may be a parenthesis/order of operations issue. I seem to recall
> having this same issue when I first started working with the GRB data.
> Try this:
> bt = ( planck_fk2 / ( np.log((planck_fk1 / rad) + 1 )) - planck_bc1) /
> planck_bc2
> Pete
> From: ldm-users-bounces@xxxxxxxxxxxxxxxx <ldm-users-bounces@xxxxxxxxxxxxxxxx>
> on
> behalf of Arthur A Person <aap1@xxxxxxx>
> Sent: Friday, January 12, 2018 7:43 AM
> To: ldm-users@xxxxxxxxxxxxxxxx
> Subject: [ldm-users] Problem calculating GOES-16 brightness temperature from
> radiance
> Hi...
> I'm trying to calculate brightness temperature from radiance for GOES-16 IR
> channel 7 using rebroadcast data
> but my values compared to McIDAS imagery are coming out 15 to 20 degrees C too
> warm. I'm using the following
> values and code:
> Test imagery:
> OR_ABI-L1b-RadC-M3C07_G16_s20180112232223_e20180112235008_c20180112235045.nc
> rad (radiance) is read in from and auto-scaled by netCDF,
> planck_fk1: 202263.0
> planck_fk2: 3698.18994140625
> planck_bc1: 0.4336099922657013
> planck_bc2: 0.9993900060653687
> bt = ( planck_fk2 / np.log( (planck_fk1/rad)+1 ) - planck_bc1 ) / planck_bc2
> bt = bt - 273.15
> Can anyone tell me if I'm missing a step or spot a dumb mistake?
> Thanks... Art
> --
> Arthur A. Person
> Assistant Research Professor, System Administrator
> Penn State Department of Meteorology and Atmospheric Science
> email: aap1@xxxxxxx, phone: 814-863-1563
--
Arthur A. Person
Assistant Research Professor, System Administrator
Penn State Department of Meteorology and Atmospheric Science
email: aap1@xxxxxxx, phone: 814-863-1563
