<div dir="ltr"><div><div><div><br><br></div>I could not reach the solution till now even after following the steps told in previous posts. I know I am making a silly mistake. <br><br>This is the projection information of the target location: <br><br>+proj=laea +lat_0=30 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83 +units=m +no_defs<br><br><b>GRASS 7.1.svn (SanLuis_Reservoir_LAEA):~ >g.proj -p</b><br><br>-PROJ_INFO-------------------------------------------------<br>name : Lambert Azimuthal Equal Area<br>proj : laea<br>datum : nad83<br>ellps : grs80<br>lat_0 : 30<br>lon_0 : -96<br>x_0 : 0<br>y_0 : 0<br>no_defs : defined<br>-PROJ_UNITS------------------------------------------------<br>unit : Meter<br>units : Meters<br>meters : 1<br><br><b>GRASS 7.1.svn (SanLuis_Reservoir_LAEA):~ > g.proj -w<br><br></b>PROJCS["Lambert Azimuthal Equal Area",<br> GEOGCS["grs80",<br> DATUM["North_American_Datum_1983",<br> SPHEROID["Geodetic_Reference_System_1980",6378137,298.257222101]],<br> PRIMEM["Greenwich",0],<br> UNIT["degree",0.0174532925199433]],<br> PROJECTION["Lambert_Azimuthal_Equal_Area"],<br> PARAMETER["latitude_of_center",30],<br> PARAMETER["longitude_of_center",-96],<br> PARAMETER["false_easting",0],<br> PARAMETER["false_northing",0],<br> UNIT["Meter",1]]<br><br><b>GRASS 7.1.svn (SanLuis_Reservoir_LAEA):~ > <a href="http://v.info">v.info</a> -g Image_boundary_box</b><br><br>north=823262.924419209<br>south=652223.643294404<br>east=-167210.022680164<br>west=-518209.054236328<br>top=0.000000<br>bottom=0.000000<br><br><br></div><span style="color:rgb(0,0,255)"><b>I should have got this <span style="color:rgb(255,0,255)">(This is correct)</span>:<br><br>north:1638674.575<br>south:1481984.575<br><br>east:1157941.598<br>west:817651.598<br><br></b></span></div><span style="color:rgb(0,0,255)"><b><span style="color:rgb(0,0,0)">Any clue, where am I wrong?</span><br></b></span><div><div><br></div></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Oct 20, 2015 at 4:45 PM, Moritz Lennert <span dir="ltr"><<a href="mailto:mlennert@club.worldonline.be" target="_blank">mlennert@club.worldonline.be</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">On 20/10/15 19:08, Uttam Kumar wrote:<br>
</span><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">
<br>
<br>
I have been trying for a long time. Something wrong is going on. I<br>
appreciate if you can correct me.<br>
<br>
<br>
I have all my source images in sinusoidal projection in a location<br>
called "Landsat_sinu".<br>
<br>
My target locatoin is "Landsat_laea" I tried using the default option in<br>
GRASS GUI as follows:<br>
<br></span>
1.) *Select coordinate system parameters from a list*<br>
<br>
2.) Projection code: *laea*<span class=""><br>
<br>
3.) Datum with associated ellipsoid:<br></span>
Central parallel: *30*<br>
Central Meridian: *-96*<br>
False easting: *0*<br>
False northing: *0*<br>
<br>
4.) Datum code: *nad83*<br>
5.) Select from the list of datum transformation: *1 used in whole nad83<br>
region*<span class=""><br>
<br>
+proj=laea<br>
+lat_0=30<br>
+lon_0=-96<br>
+x_0=0<br>
+y_0=0<br>
+no_defs<br>
+a=6378137<br>
+rf=298.257222101<br>
+towgs84=0.000,0.000,0.000<br>
to_meter=1<br>
+datum=nad83<br>
<br>
Finish.<br>
<br>
Is everything ok with this for the below (required) target definition?<br>
<br></span>
**PROJ.4 : '+proj=laea +lat_0=30 +lon_0=-96 +x_0=0 +y_0=0 +datum=NAD83<br>
+units=m +no_defs '**<span class=""><br>
<br>
Looks like at some point I am making a small mistake. I must get this as<br>
the projected coordinates.<br>
<br></span>
*north=1064601.38274499<br>
south=830176.771464028<br>
east=-1960125.15283348<br>
west=-2265106.68066176*<br>
</blockquote>
<br>
And what is wrong with these coordinates ? Those are exactly the ones I get and they are very close to the ones you got from ENVI:<span class=""><br>
<br>
> > Upper Left (-2265106.681W, 1064601.383N)<br>
> > Lower Left (-2265106.681W, 830181.383N)<br>
> > Upper Right (-1960126.681W, 1064601.383N)<br>
> > Lower Right (-1960126.681W, 830181.383N)<br>
<br></span>
i.e. 4.6m difference for South and 1.5m difference for East. You would have to check how the NAD83 conversion is done exactly to see if the difference could come from there.<br>
<br>
Moritz<br>
<br>
<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span class="">
<br>
<br>
Any help is appreciated.<br>
<br>
Uttam.<br>
<br>
<br>
On Wed, Oct 14, 2015 at 4:52 PM, Moritz Lennert<br></span><div><div class="h5">
<<a href="mailto:mlennert@club.worldonline.be" target="_blank">mlennert@club.worldonline.be</a> <mailto:<a href="mailto:mlennert@club.worldonline.be" target="_blank">mlennert@club.worldonline.be</a>>> wrote:<br>
<br>
[Please keep conversations on the list]<br>
<br>
On 14/10/15 23:19, Uttam Kumar wrote:<br>
<br>
_<br>
<br>
_<br>
_*This information is for the original data (Source):*_<br>
<br>
*PROJ.4 : '+proj=sinu +lon_0=0 +x_0=0 +y_0=0 +a=6371007.181<br>
+b=6371007.181 +units=m +no_defs '*<br>
<br>
<br>
Coordinate System is:<br>
PROJCS["Sinusoidal",<br>
GEOGCS["GCS_Unknown",<br>
DATUM["Unknown",<br>
SPHEROID["S_Unknown",6371007.181,0.0]],<br>
PRIMEM["Greenwich",0.0],<br>
UNIT["Degree",0.0174532925199433]],<br>
PROJECTION["Sinusoidal"],<br>
PARAMETER["False_Easting",0.0],<br>
PARAMETER["False_Northing",0.0],<br>
PARAMETER["longitude_of_center",0.0],<br>
UNIT["Meter",1]]<br>
Origin = (-10801805.197699999436736,4130102.079069999977946)<br>
Pixel Size = (30.000000000000000,-30.000000000000000)<br>
<br>
*<br>
_This information is for the destination data (Target):_*<br>
<br>
*PROJ.4 : '+proj=laea +lat_0=30 +lon_0=-96 +x_0=0 +y_0=0<br>
+datum=NAD83<br>
+units=m +no_defs '*<br>
<br>
<br>
In your first mail you said:<br>
<br>
Lambert Azimuthal Equal Area, Datum: WGS84<br>
<br>
but here the datum is NAD83.<br>
<br>
Using your projection info, I get almost exactly the same results in<br>
GRASS as you report from ENVI:<br>
<br>
On 08/10/15 21:36, Uttam Kumar wrote:> Reprojected in ENVI (Lambert<br>
Azimuthal Equal Area, Datum: WGS84)<br>
> -------------------------------------------------------------------------<br>
> Corner Coordinates:<br>
><br>
> Upper Left (-2265106.681W, 1064601.383N)<br>
> Lower Left (-2265106.681W, 830181.383N)<br>
> Upper Right (-1960126.681W, 1064601.383N)<br>
> Lower Right (-1960126.681W, 830181.383N)<br>
<br>
<br></div></div>
GRASS 7.0.1 (test_LAEA):~ > <a href="http://v.info" rel="noreferrer" target="_blank">v.info</a> <<a href="http://v.info" rel="noreferrer" target="_blank">http://v.info</a>> -g Image_Boundary_box<span class=""><br>
north=1064601.38274499<br>
south=830176.771464028<br>
east=-1960125.15283348<br>
west=-2265106.68066176<br>
<br>
<br>
Don't have the time now to explore the exact differences, but either<br>
it's a question of definition of the bounding box, or it possibly be<br>
a question of which specific NAD83 transformation parameters were used.<br>
<br>
Moritz<br>
<br>
<br>
<br>
</span></blockquote>
<br>
</blockquote></div><br></div>