[gradsusr] lon lat to km

[wendi harjupa]

Dear Mr. Jeff

I have tried to use the scipt which you suggested,
But, still I could not do it. Would you help me more...

here I send my gs file :

'reinit'
'open try2.ctl'
'set grads off'
'set mproj latlon'
'set mpdset hires'
'set gxout shaded'
'set grid on'
'set lon 100  101'
'set lat 0  1'
'define xdist = [(lon 99.7)/dlon]*[dx/2]'
'define ydist = [(lat -1.02)/dlat]*[dy/2]'
'set z 5'
'set t 1'
'd ref'

Below is my ctl file :

DSET 1013.dat
TITLE  RADAR
OPTIONS  TEMPLATE LITTLE_ENDIAN
UNDEF  -1000
XDEF    321 LINEAR    99.688120996    0.004492369
YDEF    321 LINEAR    -1.083708891    0.004522556
ZDEF    39  LINEAR   1.0 0.5
TDEF    15 LINEAR 13:00Z10apr2004  4mn
VARS    2
ref 39  99  Reflectivity(dBZ)
vel 39  99  Doppler Velocity(m/s)
ENDVARS


Would you check my gs file, is there something that I have to revise??

Thank you very much.

Best regards,
wendi



On Fri, Feb 1, 2013 at 10:34 AM, Jeff Duda <jeffduda319 at gmail.com> wrote:

> These commands will help.
>
> 'define dx = 6.371e3*cos(lat*(3.14159/180))*cdiff(lon,x)*(3.14159/180)'
> 'define dy = 6.371e3*cdiff(lat,y)*(3.14159/180))'
>
> They define grid increments in terms of spatial distance rather than
> geographic distance.  If you're trying to change the axes and tick marks,
> you'll have to define an origin and define your x and y distances based on
> that.  For instance, if you set your lower left domain corner (latitude 0
> and longitude 100), then you can define your coordinate distances using
>
> 'define xdist = [(lon-100)/dlon]*[dx/2]'
> 'define ydist = [(lat-0)/dlat]*[dy/2]'
>
> I think this should work, but I haven't tested it myself, so I don't know.
>  dlon and dlat are the step values from the XDEF and YDEF lines of the
> control file, respectively.
>
> Jeff Duda
>
> On Thu, Jan 31, 2013 at 7:02 AM, wendi harjupa <wendiharjupa at gmail.com>wrote:
>
>> Dear Sir/Madam
>>
>> I need help
>> I have problem with grads command,
>> I am not well understand with command gr2XY,
>>
>> Actually I want to convert the lon 100  to 101, and lat 0 to 1 to
>> distance (km)
>> let think that lon 100 is 0 km, and lat 0 is 0 km,
>>
>> what command I can use to convert lon and lat to km?
>>
>> Thank you very much for your help
>>
>> best regards,
>> --
>> -------------
>> Wendi Harjupa. ST
>> Shimane University Graduate School of Engineering Sciences
>> Department of Electronic Control Systems
>> Remote Sensing Laboratory
>> s119447
>> Cellphone : +81-080-4268-6676
>> email : wendi at rslab.riko.shimane-u.ac.jp
>>
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
>
>
> --
> Jeff Duda
> Graduate research assistant
> University of Oklahoma School of Meteorology
> Center for Analysis and Prediction of Storms
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>


-- 
-------------
Wendi Harjupa. ST
Shimane University Graduate School of Engineering Sciences
Department of Electronic Control Systems
Remote Sensing Laboratory
s119447
Cellphone : +81-080-4268-6676
email : wendi at rslab.riko.shimane-u.ac.jp
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