% Copyright (C) 2012 The HDF Group
%
% This example code illustrates how to access and visualize GESDISC AIRS Swath
% in MATLAB using the OpenDAP Structs Command Line Tool. 
% http://www.opendap.org/download/ml-structs.html

%  If you have any questions, suggestions, comments  on this example,
% please use the HDF-EOS Forum (http://hdfeos.org/forums). 
%
%  If you would like to see an  example of any other NASA HDF/HDF-EOS
% data product that is not listed in the HDF-EOS Comprehensive Examples page
% (http://hdfeos.org/zoo), feel free to contact us at
% eoshelp@hdfgroup.org or post it at the HDF-EOS Forum (http://hdfeos.org/forums).


% Run this script as follows:
%
% >matlab -nosplash -nodesktop -r  AIRS_L2_radiances_channel567_OpenDAP
%
% Then, you'll get an image file: 
%
%   AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425_radiances567_matlab.jpg
% 
% Last update: 10/23/2012
% Tested under: MATALB 2012a
clear

% Add the path to the Matlab-OpenDAP library installation bin directory
addpath /scr/kent/matlab-opendap/dapbin/bin

% Open the HDF-EOS2 Swath File via the OpenDAP interface
loaddap(['http://eosdap.hdfgroup.uiuc.edu:8080/opendap/data/' ...
         'NASAFILES/hdf4/AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425.hdf']);

% loaddap creates the structures:
% ...
% matrix radiances (45 x 30 x 2378) with 3210300 elements.
% ...
% matrix Latitude (45 x 30) with 1350 elements.
% matrix Longitude (45 x 30) with 1350 elements.
% ...

% This information is also returned as a Matlab structure by
attrs=loaddap('-A', ...
              'http://eosdap.hdfgroup.uiuc.edu:8080/opendap/data/NASAFILES/hdf4/AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425.hdf');
% Either way, the structure element name must be known in advance to access the
% structure element.
% The structure element name is the same as the attribute name, which can be
% obtained via the OpenDAP web services interface at URL:
% http://eosdap.hdfgroup.uiuc.edu:8080/opendap/data/NASAFILES/hdf4/AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425.hdf.das

% radiances, Latitude and Longitude are already of type double

% Extract 2-D data at level 568 of radiances: 30x2378x45 double
data=squeeze(radiances(:,568,:));

% Lat, Long and radiances must have the same dimensions.
% -- radiances is transposed
dataTranspose = data';

% Replace the fill value with NaN (_FillValue=-9999.000000 from attributes)
dataTranspose(dataTranspose==-9999) = NaN;

% Plot the data using surfacem and axesm
pole=[-90 0 0];
latlim=[floor(min(min(Latitude))),ceil(max(max(Latitude)))];
min_data=floor(min(min(dataTranspose)));
max_data=ceil(max(max(dataTranspose)));

figure_handle=figure('Name', ...
                     'AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425_radiances_channel567', ...
                     'visible','off');

axesm('MapProjection','stereo','MapLatLimit',latlim,...
      'Origin',pole,'Frame','on','Grid','on', ...
      'MeridianLabel','on','ParallelLabel','on');

coast = load('coast.mat');

% surfacem is faster than contourfm, but produces less desirable graph
% surfacem(Latitude,Longitude,dataTranspose);
contourfm(Latitude,Longitude,dataTranspose,'LineStyle','none');

colormap('Jet');
caxis([min_data max_data]); 
cbar_handle=colorbar('YTick', min_data:4:max_data);
set (get(cbar_handle, 'title'), 'string', 'mW/m^{2}/cm^{-1}/sr');

plotm(coast.lat,coast.long,'k');

title({'AIRS.2002.12.31.001.L2.CC\_H.v5.0.14.0.G07282131425';'Radiances at channel=567'} ,'FontSize',16,'FontWeight','bold');

scrsz = get(0,'ScreenSize');

if ishghandle(figure_handle)
    set(figure_handle,'position',scrsz,'PaperPositionMode','auto');

    saveas(figure_handle, ...
           'AIRS.2002.12.31.001.L2.CC_H.v5.0.14.0.G07282131425_radiances567_matlab.jpg');
end