<div dir="ltr"><div>Oops. The center grid point is at (1001, 1001), not (1000, 1000). But those offset formulas are correct as shown.</div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 22, 2022 at 1:53 PM Dave Allured - NOAA Affiliate <<a href="mailto:dave.allured@noaa.gov">dave.allured@noaa.gov</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr"><div>Barry, this file lacks the coordinate variables that are normally provided in most published Netcdf data sets. However, there appears to be almost enough information in the global attributes to construct grid coordinates. There are reference latitude and longitude, and the X and Y grid spacing.</div><div><br></div><div>The reference coordinates are ambiguous. My guess is they are probably grid center coordinates, but not sure. With odd numbers for both X and Y dimensions, that suggests that the center grid point (1000, 1000) is right at (40N, 110W).</div><div><br></div><div>So just calculate X and Y coordinate vectors centered on the reference coordinates, attach them to the data variable, then plot normally. To minimize precision loss, use <b>ispan</b> and divide by 100 as the final step, because 0.01 step size is not exactly representable in floating point. (Not very important.) E.g.:</div><div><br></div><div><div> lats = lat_center + (double (ispan (-1000, 1000, 1)) / 100)</div><div> lons = lon_center + (double (ispan (-1000, 1000, 1)) / 100)</div></div><div dir="ltr"><br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Sep 22, 2022 at 11:28 AM Barry Lynn via ncl-talk <<a href="mailto:ncl-talk@mailman.ucar.edu" target="_blank">ncl-talk@mailman.ucar.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;border-left-color:rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hello:<div><br></div><div>I am wondering if there is a simple way to plot this radar data correctly on a grid.</div><div><br></div><div>I can extract the radar data, no problem, but am wondering how to specify the lat/lon of the data. Can it be obtained from the radar data itself?</div><div><br></div><div>Thank you.</div><div><br></div><div>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures">Variable: b</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures">Type: file</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures">filename:<span style="white-space:pre-wrap"> </span>20120415-080000</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures">path:<span style="white-space:pre-wrap"> </span>20120415-080000.netcdf</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>file global attributes:</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>TypeName : mrefl_mosaic</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>DataType : LatLonHeightGrid</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Time : 1334476800</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>FractionalTime :<span> </span>0</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>MissingData : -999</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>RangeFolded : -1000</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Latitude : 40</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Longitude : -110</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Height : 500</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>LatGridSpacing : 0.01</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>LonGridSpacing : 0.01</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>attributes :<span> </span></span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>dimensions:</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Ht = 31</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Lat = 2001</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Lon = 2001</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>variables:</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>short mrefl_mosaic ( Ht, Lat, Lon )</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Units :<span style="white-space:pre-wrap"> </span>dBZ</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Scale :<span style="white-space:pre-wrap"> </span>10</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139);min-height:22px"><span style="font-variant-ligatures:no-common-ligatures"></span><br></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>float Height ( Ht )</span></p>
<p style="margin:0px;font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:19px;line-height:normal;font-family:Menlo;background-color:rgb(254,244,139)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>Units :<span style="white-space:pre-wrap"> </span>Meters</span></p>-- <div dir="ltr"><div dir="ltr"><div><div dir="ltr">Barry H. Lynn, Ph.D<div><div>Senior <font color="#000000">Scientist, Lecturer,</font></div><div><div><font color="#000000">The Institute of Earth Sciences, <br>The Hebrew University of Jerusalem, <br>Givat Ram, Jerusalem 91904, Israel <br></font></div><font color="#000000">Tel: 972 547 231 170<br>Fax: (972)-25662581</font></div></div><div><span style="color:rgb(136,136,136)"><br></span></div><div>Weather It Is, LTD<br>Weather and Climate Focus<br><a href="http://weather-it-is.com" target="_blank">https://weather-it-is.com</a><br>Jerusalem, Israel<br>Local: 02 930 9525<br>Cell: 054 7 231 170<br>Int-IS: x972 2 930 9525</div></div></div></div></div></div></div>
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