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Messages - pdjakow

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Arctic sea ice / Re: 2016 sea ice area and extent data

« on: November 18, 2016, 05:34:02 PM »

Quote from: Wipneus on November 18, 2016, 03:59:27 PM

Last addition, area/extent, normal and anomaly in one graph Cryosphere Today-style.

Are these graphs normalized as title said?

Developers Corner / Re: Problem with IMS snow&ice data

« on: November 18, 2013, 11:37:43 AM »

I used lat/lon data files, as Chris said. This working good, however files are large and must be loaded into memory.

I have still problem with proper pixel drawing.

Developers Corner / Re: Problem with IMS snow&ice data

« on: November 17, 2013, 09:08:23 AM »

I'm working on ASCII files:
ftp://sidads.colorado.edu/pub/DATASETS/NOAA/G02156/4km/2013/

Image above was created with reading this ASCII file line by line and values represented by colors:

light blue (0) - outside northern hemisphere
blue (1) - ocean
green (2) - land
gray (3) - ice
white (4) - snow

Oryginal size image is here:
http://meteomodel.pl/klimat/IMS.png

Edit

Of course if I replace line:

bmp.SetPixel(i,j,Color.LoghtBlue)

with

bmp.SetPixel(6143-i,j,Color.LightBlue)

"Mirror effect" will be removed.
http://meteomodel.pl/klimat/IMS3.png

Developers Corner / Problem with IMS snow&ice data

« on: November 16, 2013, 05:57:20 PM »

Hello all!

I have problems with proper interpretation of IMS snow&ice data on NSIDC:
http://nsidc.org/data/docs/noaa/g02156_ims_snow_ice_analysis/

What I want to do is:

- get 4km ASCII file
- convert data file to something like dbf file:

lat lon value

Unfortunetaly data file is in polar stereographic projection:

Quote

Northern Hemisphere coverage is available at approximately 4-km and at approximately 24-km resolution. The bounding coordinates are as follows:

Southernmost Latitude: 0° N
Northernmost Latitude: 90° N
Westernmost Longitude: 180° W
Easternmost Longitude: 180° E

Data are in a polar stereographic projection centered at 90° N with the vertical longitude from the Pole at 80° W and the standard parallel at 60° N.

Example data files from NATICE:
http://www.natice.noaa.gov/pub/ims/snow/6144asc/2013/

There is 6144x6144 data points, and I don't know how to calculate position of each value. I even try to make image from that data, and that was funny in some way