<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>Hi Xiaoming, <br></div><div><br></div><div>Please let's keep this conversation on the ncl_talk, unless we really need to take it offline.</div><div><br></div><div>Are you familiar with Proj4? Playing around with that, I tried:</div><div><br></div><div>$ proj +proj=lcc +lon_0=-90 +lat_0=40 +lat_1=30 +lat_2=60 <br></div><div>-90 40 <---input<br></div><div>0.00 0.00 <----returned value</div><div><br></div><div>This is a specification for a lambert conformal projection, with parameters:</div><div> +lon_0=-90 longitude at center of projection<br></div><div> +lat_0=40 latitude at center of projection<br></div><div> +lat_1=30 1st standard parallel<br></div><div> +lat_2=60 2nd standard parallel</div><div><br></div><div>I enter the lon/lat pair -90 40 and get back 0 0 in units of meters, which checks out as the center of the projection. <br></div><div><br></div><div>So, the inverse "de-projection" using the XORG/YORG values in your file yields:</div><div><br></div><div>$ invproj +proj=lcc +lat_0=40 +lat_1=30 +lat_2=60 +lon_0=-90 -f "%.6f"<br></div><div>-1296000 -1404000 <---- input<br></div><div>-102.797916 26.266793 <---returned value</div><div><br></div><div>Which I can believe -102.7/26.2 is the lower-left corner of tile #9, just eyeing the tilemap</div><div><br></div><div>That all said, I'm still not certain you are going to get good alignment across your area-of-interest just by specifying LL/UR corners, due to the distortion inherent to the lamber conformal. If you find that to be the case, the "native grids" approach I mentioned previously may be required.<br></div><div> <br></div><div>Hope that helps...</div><div>Rick</div><div><br></div><div><br></div></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Feb 7, 2019 at 7:48 AM Hu, Xiaoming <<a href="mailto:xhu@ou.edu" target="_blank">xhu@ou.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
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<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">Rick <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"><br>
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<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"> Thanks for your reply, I think I agree with all your interpretation.
<br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"> <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">I tried to plot Juniper for tile 9 in this map: <a class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-txt-link-freetext" href="https://www.cmascenter.org/sa-tools/documentation/4.2/html/smoke_bio_inputs.html" target="_blank">
https://www.cmascenter.org/sa-tools/documentation/4.2/html/smoke_bio_inputs.html</a></div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">using <a class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-txt-link-freetext" href="http://www.caps.ou.edu/micronet/temp/forJianPing/plot_xhu_BELD3_Juniper.ncl" target="_blank">
http://www.caps.ou.edu/micronet/temp/forJianPing/plot_xhu_BELD3_Juniper.ncl</a><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">The data is at <a class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-txt-link-freetext" href="http://www.caps.ou.edu/micronet/temp/forJianPing/b3_a.tile9.nzero.ncf" target="_blank">
http://www.caps.ou.edu/micronet/temp/forJianPing/b3_a.tile9.nzero.ncf</a><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">Based on my current technique, I need <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">; res@mpLeftCornerLatF = lat2d(0,0)<br>
; res@mpLeftCornerLonF = lon2d(0,0)<br>
to plot accurately to match tile 9 in <a class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-txt-link-freetext" href="https://www.cmascenter.org/sa-tools/documentation/4.2/html/smoke_bio_inputs.html" target="_blank">
https://www.cmascenter.org/sa-tools/documentation/4.2/html/smoke_bio_inputs.html</a><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"> I wonder if you have a solution. <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"><br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">I am ccing to Dennis if he'd like to give it a try. <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"> </div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">Thanks a lot<br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">Xiaoming <br>
</div>
<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix"><br>
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<div class="gmail-m_-6074412252389754182gmail-m_-990182510301764868moz-cite-prefix">On 2/7/19 8:32 AM, Rick Brownrigg wrote:<br>
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<blockquote type="cite">
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<div dir="ltr">
<div>Hi Xiaoming,</div>
<div><br>
</div>
<div>Yes, NCL could interpret this -- in principle -- but not without more information. The data appear to be in a projected coordinate space. See the examples at</div>
<div><br>
</div>
<div> <a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__ncl.ucar.edu_Applications_native.shtml&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=W32uvgk4VvmL2B6mi-37Lg&m=Rm0xpdrfxUY-YcoOdw7qGfGdEQxejDWnG_-7sJ75n0k&s=n80Mqz4HlpboRb4qhkfzNfZbPlcC7HtYajvc66OEtFA&e=" target="_blank">
http://ncl.ucar.edu/Applications/native.shtml</a><br>
</div>
<div><br>
</div>
<div>The precise cartographic projection parameters are not immediately evident from the metadata given above, although we can make some guesses (it would be better to know for certain!).<br>
</div>
<div><br>
</div>
<div>These parameters:</div>
<div>
<div> :XCENT = -90. ;<br>
</div>
<div> :YCENT = 40. ;<br>
</div>
<div> :XORIG = -1296000. ; <br>
</div>
<div> :YORIG = -1404000. ;<br>
</div>
<div> :XCELL = 1000. ;<br>
</div>
<div> :YCELL = 1000. ;</div>
<div><br>
</div>
<div>XCELL/YCELL affirm the data are at 1 1km spacing. The XCENT/YCENT and XORIG/YORIG give the correspondence between the projected and geographical spaces for the geographical location 90W/40N, a central location in North America.<br>
</div>
<div><br>
</div>
<div>These parameters:<br>
</div>
<div><br>
</div>
<div><span> :P_ALP = 30. ;<br>
</span>
<div> :P_BET = 60. ;<br>
</div>
<div> :P_GAM = -90. ;</div>
<div><br>
</div>
<div>Looking at some of the maps at the EPA site you reference, these could very well be projection parameters for a Lambert Conformal projection, with P_ALP/P_BET being more commonly referred to as "standard parallels" and P_GAM being the "standard meridian".
The values look quite right for North America, but again all of this is conjecture.
<br>
</div>
<div><br>
</div>
<div>Hope this helps...</div>
<div>Rick<br>
</div>
</div>
</div>
</div>
</div>
<br>
<div class="gmail_quote">
<div dir="ltr" class="gmail_attr">On Thu, Feb 7, 2019 at 5:08 AM xiaoming Hu <<a href="mailto:yuanfangcan@hotmail.com" target="_blank">yuanfangcan@hotmail.com</a>> wrote:<br>
</div>
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div dir="ltr">
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
I try to plot spatial distribution of BELD data from <a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__www.epa.gov_air-2Demissions-2Dmodeling_biogenic-2Demissions-2Dlanduse-2Ddatabase-2Dversion-2D3-2Dbeld3&d=DwMFaQ&c=qKdtBuuu6dQK9MsRUVJ2DPXW6oayO8fu4TfEHS8sGNk&r=W32uvgk4VvmL2B6mi-37Lg&m=Rm0xpdrfxUY-YcoOdw7qGfGdEQxejDWnG_-7sJ75n0k&s=Ye9wZ_kUZae0pNvfQ_2QtXtPV5s87-kpy-5IXyYyuqM&e=" target="_blank">https://www.epa.gov/air-emissions-modeling/biogenic-emissions-landuse-database-version-3-beld3</a></div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
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<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
the NetCDF files don't provide latitude/longitude, only with information of</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<span> :P_ALP = 30. ;<br>
</span>
<div> :P_BET = 60. ;<br>
</div>
<div> :P_GAM = -90. ;<br>
</div>
<div> :XCENT = -90. ;<br>
</div>
<div> :YCENT = 40. ;<br>
</div>
<div> :XORIG = -1296000. ; <br>
</div>
<div> :YORIG = -1404000. ;<br>
</div>
<div> :XCELL = 1000. ;<br>
</div>
<div> :YCELL = 1000. ;<br>
</div>
<div> :VGTYP = -9999 ;<br>
</div>
<div> :VGTOP = -9.e+36f ;<br>
</div>
<div> :VGLVLS = 0.f, 0.f ;<br>
</div>
<div> :GDNAM = "BELD3_TILE9 " ;<br>
</div>
<span></span><br>
</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
It there anyway NCL could interpret this ? </div>
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<br>
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<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Thanks</div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
Xiaoming </div>
<div style="font-family:Calibri,Helvetica,sans-serif;font-size:12pt;color:rgb(0,0,0)">
<br>
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<br>
</div>
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