[ncl-talk] GOES16 netCDF files

Fri Jan 19 15:04:02 MST 2018

Hi Tim,

Those are big variables, but not that big.  Are you trying to read in large
numbers of them?

Rick

On Fri, Jan 19, 2018 at 1:54 PM, Tim Risner <trisner at awis.com> wrote:

> Works great Mary, and you can easily pull the sat wavelength you need from
> it.
> One issue I did run into was if you use the “Full Disk” files rather then
> the “CONUS” files used in the example, you get
> what I expect to be a memory issue?
>
> Error to screen
> *******************
> “fatal: NclMalloc Failed:[errno=12] Segmentation fault” error.
>
>
> info
> ******
> Variable: phi
> Type: double
> Total Size: 235358208 bytes
>             29419776 values
> Number of Dimensions: 2
> Dimensions and sizes: [5424] x [5424]
> Coordinates:
> Number Of Attributes: 1
>   _FillValue : -999
>
> Variable: lambda
> Type: double
> Total Size: 235358208 bytes
>             29419776 values
> Number of Dimensions: 2
> Dimensions and sizes: [5424] x [5424]
> Coordinates:
> Number Of Attributes: 1
>   _FillValue : -999
>
> Variable: data
> Type: float
> Total Size: 117679104 bytes
>             29419776 values
> Number of Dimensions: 2
> Dimensions and sizes: [y | 5424] x [x | 5424]
> Coordinates:
>             y: [0..5423]
>             x: [0..5423]
> Number Of Attributes: 16
>   lon2d : <ARRAY of 29419776 elements>
>   lat2d : <ARRAY of 29419776 elements>
>   long_name : ABI Cloud and Moisture Imagery reflectance factor
>   standard_name : toa_lambertian_equivalent_albedo_multiplied_by_cosine_
> solar_zenith_angle
>   _Unsigned : true
>   sensor_band_bit_depth : 12
>   downsampling_method : average
>   units : 1
>   resolution : y: 0.000056 rad x: 0.000056 rad
>   coordinates : band_id_C02 band_wavelength_C02 t y x
>   grid_mapping : goes_imager_projection
>   cell_methods : t: point area: sum (interval: 0.000014 rad)
>   ancillary_variables : DQF_C02
>   _FillValue_original : -1
>   _FillValue : -1
>   valid_range : (  0, 1.299999 )
>
>
>
>
>
> On Jan 11, 2018, at 6:07 PM, Mary Haley <haley at ucar.edu> wrote:
>
> Hi Tim,
>
> My apologies for getting back to you so late. We got side-tracked with
> another harder GOES16 issue (regridding a large GOES16 variable) and wanted
> to finish that up to make sure we were doing things correctly.
>
> Rick and Bill (members of the NCL development team) spent some time
> looking into documentation for GOES16 and figured out how to calculate the
> lat / lon values, given the Y / X coordinates and map projection
> information on the file. No sooner than this was done that the satellite
> was repositioned, and we had to tweak the calculations a little.
>
> I've attached the NCL scripts that Rick created, and the plot it
> generates. This script should work on the new GOES16 data as well.
>
> You need to run:
>
>  ncl plot_goes16.ncl
>
> The CMI_16 variable was arbitrarily chosen, but we did chose 16 over the
> other numbers because it was more interesting.
>
> I understand that there are different channels, and a better way to plot
> this data might be to overlay the different channels with different
> opacities set.  I need to look into how another user did this, and I'll
> post back here if I ever get around to it.
>
> --Mary
>
>
>
>
> On Wed, Dec 13, 2017 at 1:02 PM, Tim Risner <trisner at awis.com> wrote:
>
>> thanks Rick, others.
>> version is 6.4.0
>> running on Linux Amazon EC2 instance. x86_64 x86_64 x86_64 GNU/Linux
>> testing GOES16 file attached.
>> I obtained such file from the Amazon AWS bucket system that is now
>> publicly accessible by the gov't/Amazon.
>> Information on file lists it as a GOES16 netcdf file.
>>
>> I assumed I could simply replace the file in the example for GOES 11
>> example here: http://www.ncl.ucar.edu/Applications/Scripts/goes_1.ncl
>> and all would work if the files and datasets were exchangeable.
>> Assumptions are likely my problem.
>>
>> Error output:
>>
>> fatal:["Execute.c":132]:variable (data) is not in file
>> (/var/NCL/INPUT/GOES16.nc)
>> fatal:["Execute.c":6381]:variable (data) is not in file (f)
>> fatal:["Execute.c":8640]:Execute: Error occurred at or near line 4 in
>> file /var/NCL/CODE/testgoes.nc
>>
>>
>>
>>
>> *Tim Risner*
>> *Operational Meteorologist*
>> *(888) 798-9955 ext 1006 <(888)%20798-9955>*
>>
>> <http://www.awis.com/>[image:
>> https://www.facebook.com/AWISWeatherServices/]
>> <https://www.facebook.com/AWISWeatherServices/>
>> <https://twitter.com/awisweather>
>>
>> On Wed, Dec 13, 2017 at 9:02 AM, Rick Brownrigg <brownrig at ucar.edu>
>> wrote:
>>
>>> Hi Tim,
>>>
>>> Do you have a dataset you could share?  I download some data from this
>>> site:
>>>
>>> https://www.goes-r.gov
>>>
>>> but not knowing what I'm really looking for, I could not ascertain that
>>> it was specifically GOES16. NCL was able to read it.
>>>
>>> I should also ask what version of NCL are you working with?
>>>
>>> If your dataset is too large to email, you can post it to our FTP site:
>>>
>>> http://ncl.ucar.edu/ftp_files.shtml
>>>
>>> Rick
>>>
>>> On Wed, Dec 13, 2017 at 7:35 AM, Tim Risner <trisner at awis.com> wrote:
>>>
>>>> Hello All,
>>>> I am curious as to what the GOES16 netCDF plan is for NCL.
>>>> I've attempted to ingest the new GOES16 netCDF into generic GOES code
>>>> found on the examples pages, but am getting a variables not found error
>>>> when attempting to produce an image. Variable not found is "data". I assume
>>>> this is due to the differences between the GOES16 netCDF files and the
>>>> older GOES products? or is it just operator error and GOES16 netcdf files
>>>> should work?
>>>>
>>>> Thanks!!!
>>>>
>>>>
>>>> *Tim Risner*
>>>> *Operational Meteorologist*
>>>> *(888) 798-9955 ext 1006 <(888)%20798-9955>*
>>>>
>>>> <http://www.awis.com/>[image:
>>>> https://www.facebook.com/AWISWeatherServices/]
>>>> <https://www.facebook.com/AWISWeatherServices/>
>>>> <https://twitter.com/awisweather>
>>>>
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>>>
>>
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>>
> <goes16.png><plot_goes16.ncl><goesYXtoLatLon.ncl>
>
>
>
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