MODIS HDF

Mike Bosilovich mike.bosilovich at GMAIL.COM
Fri Nov 30 12:29:36 EST 2007


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
> >
> >
>
>
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