MODIS HDF

[Jayakrishnan PR]

I can plot MODIS level 2 HDF data in Grads. This is employed by assuming the
points in the pass of satellite as station data.

On Nov 30, 2007 10:59 PM, Mike Bosilovich <mike.bosilovich at gmail.com> wrote:

>
> Hi!
>
> If you could, you may need to be more specific about the MODIS data you
> are using. I haven't been able to get MODIS L2 data into grads directly, but
> MODIS L3 data can be read into grads, with the right xdf file
>
> Below are two examples, the first opens MODIS MOD11C1 data (Land surface
> Temperature, daily 0.05 degree grid), and the second opens MOD08(Monthly 1
> degree atmospheric water vapor) the grads call to "open" opens these data.
>
> I've used HDFLook to dump L2 granules to a binary that can be opened in
> Grads, but that is rather tedious. There are probably better ways for L2.
>
> Mike
>
> DSET MOD11/data/Y2004/M%m2/MOD11C1.A2004%m2%d2.004.hdf
> title MODIS Land Surface Temperature (LST) CMG v4
> DTYPE hdfsds
> OPTIONS yrev template
> unpack scale_factor add_offset
> undef -999.0
> XDEF 7200 linear -180 0.05
> YDEF 3600 linear  -90 0.05
> ZDEF 1 linear 1 1
> TDEF 31  linear 01JUL2004 1dy
> VARS 6
> LST_Day_CMG=>LSTDay 0 y,x Daily daytime 3min CMG Land-surface Temp
> LST_Night_CMG=>LSTNite 0 y,x Daily nighttime 3min CMG Land-surface Temp
> QC_Day=>QCDay  0 y,x Quality control for daytime LST and emissivity
> QC_Night=>QCNite  0 y,x Quality control for nighttime LST and emissivity
> Day_view_time=>DayTime  0 y,x Time of daytime LST observation (UTC)
> Night_view_time=>NiteTime  0 y,x Time of nighttime LST observation (UTC)
> ENDVARS
>
> -------------------------------------------------
>
> DSET MOD08/MOD08_M3.A%y4%m2.004.hdf
> dtype hdfsds
> title MODIS MOD08 Atmosphere monthly 1 degree CMG
> UNDEF 0 _FillValue
> unpack scale_factor add_offset
> OPTIONS yrev template
> XDEF 360 linear -180 1.00
> YDEF 180 linear  -90 1.00
> ZDEF 1 linear 1 1
> TDEF 75 linear 01MAY2000 1mo
> VARS 1
> Atmospheric_Water_Vapor_Mean_Mean=>tcwcm 0 y,x Total Column Precipitable
> Water V
> apor -- IR Retrieval: Mean of Daily Mean
> ENDVARS
>
>
>
>
>
> > From: Jayakrishnan PR <prjayakrishnan at gmail.com>
> > Date: Nov 30, 2007 11:46 AM
> > Subject: Re: MODIS HDF
> > To: GRADSUSR at list.cineca.it
> >
> >
> >
> > Dear Mr.Jean,
> >        Last six months I was trying to plot MODIS data in Grads.
> > Today I succeeded with the help of grads user group and some of my
> > friends. There is two ways to plot the MODIS HDF data.
> > 1) Firstly convert the hdf data into ascii form using any software
> > such as ENVI, HDF explorer, etc.
> > 2) Using the ascii code we are able to know the latitude, longitude
> > and the parameter at different heights.
> > 3) Construct a fortran program which will convert this data into
> > station format and I have also written a c program which will convert
> > the out put of fortran into station data format.
> > 4) Now write a ctl file for the station data
> > 5) Run the station map utility using the command stnmap -i
> > stnexample.ctl
> > 6)open the ctl file in grads
> > 7)plot the data. Now set gxout stnmark
> > 8) then set cmark 11( or something)
> >   set digsiz 0.14
> >    now display and it will give the values in the data points as
> > markers. This is a quite good approach because we are not doing any
> > interpolation techniques. Just the pure data.
> >
> > There is another way also. We can directly plot the hdf files in
> > grads. For that we have to write a Data descriptor file. That I am
> > trying now. Yet not succeeded. If you succeeded first, please let me
> > know.
> >     If you want the program or ctl files that I have used dont
> > hesitate to ask me.
> > sincerely
> >
> >
> >
> >
> >
> > On Nov 30, 2007 9:55 PM, Jean Pierre Arabonis < arabonis at egs.uct.ac.za>
> > wrote:
> > >
> > > I tried using grads for the modis data some years ago with no success,
> > I ended up using Envi - interestingly if you re-save the data as hdf in Envi
> > then you can open it with grads. I suspect is is some incompatibility with
> > the file format.
> > >     Please let me know if you do find a solution
> > >     Good Luck
> > >        JP
> > >
> > >
> > >
> > >
> > >
> > > Jayakrishnan PR wrote:
> > > On Fri, 25 Apr 2003 11:28:34 -0000, Pawan Gupta <
> > pawanpgupta at REDIFFMAIL.COM>
> > > wrote:
> > >
> > >
> > >
> > > Dear Friends
> > > Can you help me in displaying MODIS HDF format
> > >
> > > Thanks
> > > pawan
> > >
> > > ********************************************************************
> > >
> > > Dear Pawan,
> > > I also now facing the same problem to analyse MODIS data in hdf format
> > > using grads. If you got the solution, kindly help me.
> > >
> > >
> > >
> > >
> > > --
> > > Jean Pierre Arabonis
> > > arabonis at egs.uct.ac.za
> > > Tel 021 780 1021 cell 084 401 1365
> > > This email is 100% Microsoft Free
> > >
> > >
> >
> >
>


--
***********************************************
Jayakrishnan.P.R
Junior Research Fellow
Department of Atmospheric Sciences
Cochin University of Science And Technology (CUSAT), Cochin-16
Kerala, India.
Mob: 09895417565

***********************************************
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20071201/16e56365/attachment.html