How to read CMORPH precipitation data (NOAA)?

[martin claverie]

I am trying to read CMORPH precipitation data from NOAA (http://www.cpc.ncep.noaa.gov/products/janowiak/cmorph_description.html).

After many try, I was not able to manage to read the data and could not understand why. I also search on internet, and did not find any specific help.

I attach a sample file, but more file can be found in the ftp below.
https://dl.dropboxusercontent.com/u/2768652/20140205_dly-025deg_cpc%2Bcomb.Z
ftp://ftp.cpc.ncep.noaa.gov/precip/global_CMORPH/daily_025deg/

I did many try, but my what I found the more consistent was :

%%
nlat = 480;
nlon =1440;

fid=fopen(['20140205_dly-025deg_cpc+comb'],'r');
a2=fread(fid,'real*4',4,'ieee-be'); % I skip 4 because there are 2 data sets in the file
fclose all;

LonL = 0.125:0.25:360-0.125;
LatL = 59.875:-0.25:-59.875;

b=reshape(a2,[nlat nlon ]);

imagesc(LonL,LatL,b)

%%

The provider give a sample Fortran code that help me to understand how the data is organized.
ftp://ftp.cpc.ncep.noaa.gov/precip/global_CMORPH/README.cmorph.025deg_daily

The image below (found on a trusted website) should be taken as reference.
https://dl.dropboxusercontent.com/u/2768652/20140205.gif

Thank you to all of you that could help me to solve this problem...

Martin

[Francisco]

"martin claverie" wrote in message <lde3jj$90e$1...@newscl01ah.mathworks.com>...

[dawittes]

Hi Martin
I am facing the same issue as you encountered. I want to read data from cmorph using MATLAB if you can help me it would be very helpful.
I appreciate your cooperation in advance.
Dawit

[Abanjo]

Took me a bit, but saw your message and figured I'd share...

fid=fopen([path 'CMORPH_V1.0_ADJ_0.25deg-3HLY_' ctime],'r','b');
rain=fread(fid,1440*480*8,'real*4',0,'ieee-le'); % This is for the 3-hourly data
fclose(fid);

You'll have to reshape it to 1440 x 480 x 8. I am sure the hourly data is similar, although I did read that they changed some things in the new version.

Good luck.

dawittes <dawitte...@gmail.com> wrote in message <FYadnVQ3CdzD8nzJ...@giganews.com>...

[Job de Vries]

Dear all,

I found a similar approach for Matlab which i'll post below. I'm very much struggeling with the orientation of the resulting matrix, lets say I want to extrac precipitation values in Amman, Jordan I'm unclear if I extract the correct values. I end up for coordinaate 31.97 lat and 35.91 for cell index 385 and 493, but unsear If i do it correct here. Love to hear your thoughts.

% translate latitude/longitude to correct indexes
Lat_list=59.963614:-0.072771377:-60;
Lon_list=0.036378335:0.072756669:360;
Latitude = 31.973192;
Longitude = 35.909407;
lat_index = round(abs(59.963614 - Latitude) / 0.072771377);
lon_index = round(abs(0.036378335 - Longitude) / 0.072756669);

for file_nr=1:numel(All_files);
% Extract filename and date attributes
filename = All_files(file_nr).name;

% Return fid and message from the opened file
[fid, message] = fopen(filename, 'r', 'l');

% Each file contains 2 layers for each half hour there is one layer
for i = 1:2
% fread the openen rainfall binary data with dimensions 4948*1648
% use real*4 for floating points with 32 bytes
Rain = fread(fid, [4948, 1649], 'real*4');
Rain = Rain';

% Hear you read rainfall data for the relevan lat cel index and lon index cel
% Based on value from lat_list and Lon List
Rainfall = Rain(lat_index, lon_index) * 0.2;

end
fclose(fid);
end

[Liya Weldegebriel]

Hello Job,
I am struggling to import 8km-30 min CMORPH data into Matlab. I looked at your code and how were you able to read and import CMORPH data into Matlab? (i.e. the file you named All_files).  Would you mind sharing that code as well?  I am new to this and appreciate any suggestions.

I tried this code below but it is giving me error messages.

filename='ftp://ftp.cpc.ncep.noaa.gov/precip/CMORPH_V1.0/RAW/8km-30min/'

Lon=0.036378335:0.072756669:360;
Lat=-59.963614:0.072771377:60;

[fid, message] = fopen(filename, 'r','l')

for i=1:2

Rain= fread(fid, [4948,1649], 'real*4');

end
fclose(fid)


"Job de Vries" wrote in message <o61juf$m3c$1...@newscl01ah.mathworks.com>...