eccodes/doxygen/gribex/latLongGrid.html

590 lines
19 KiB
HTML

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html><!-- #BeginTemplate "/Templates/ecmwf.dwt" --><!-- DW6 -->
<head profile="http://purl.org/metadata/dublin_core">
<!-- ECMWF: Standard External Template -->
<!-- ECMWF: Version 1.062 (banner link corrected) -->
<META http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<META content="$Author: Enrico Fucile $" name="DC.Creator" />
<LINK REL="SHORTCUT ICON" href="/favicon.ico">
<!-- #BeginEditable "meta" -->
<META content="ECMWF webgroup" name="DC.Publisher" />
<META content="webgroup documents" name="DC.Subject" />
<!-- #EndEditable --> <!-- #BeginEditable "metalink" -->
<!-- Users insert meta LINK tags here -->
<!-- #EndEditable --> <!-- #BeginEditable "doctitle" -->
<title>GRIB API Manual</title>
<!-- #EndEditable --><!-- #BeginEditable "customstyle" -->
<!--put custom style here-->
<link rel="stylesheet" href="/publications/manuals/grib_api/doxygen.css" type="text/css">
<!-- #EndEditable -->
<script type="text/javascript" language="JavaScript" src=
"/assets/js/ecmwf.js">
</script>
<link rel="stylesheet" href="/assets/css/ecmwf.css" type=
"text/css">
</head>
<body bgcolor="#FFFFF2" text="#000000">
<a name="top"></a>
<table summary="Formatting Table: Page Layout" width="750" border=
"0" cellspacing="0" cellpadding="0" bgcolor="#FFFFF2">
<tr>
<td bgcolor="#CCCE9B" align="left" valign="middle"><a href="/"><img
src="/assets/images/text_logo.jpg" border="0" alt="Home page"
width="136" height="26" align="middle"></a></td>
<td bgcolor="#CCCE9B">&nbsp;</td>
<td bgcolor="#CCCE9B" valign="middle">
<form name="search" method="post" action="/cgi-bin/htsearch"><input
type="hidden" name="restrict" value="">
<table summary="Formatting Table: Actions Menu" border="0"
cellspacing="4" cellpadding="0" align="right">
<tr>
<td><a href="/" class="menuitem">Home</a></td>
<td>&nbsp;</td>
<td><a href="/your/d/room/" class="menuitem">Your Room</a></td>
<td>&nbsp;</td>
<td><a href="/tools/login/" class="menuitem">Login</a></td>
<td>&nbsp;</td>
<td><a href="/about/contact/" class="menuitem">Contact</a></td>
<td>&nbsp;</td>
<td><a href="/about/feedback/" class="menuitem">Feedback</a></td>
<td>&nbsp;</td>
<td><a href="/about/sitemap/" class="menuitem">Site Map</a></td>
<td>&nbsp;</td>
<td><a href="/tools/qsearch/" class="menuitem">Search:</a></td>
<td valign="bottom"><input type="hidden" name="exclude" value="">
<input type="hidden" name="config" value="wmss"> <input type="text"
name="words" maxlength="128" size="8" style=
"height:20px; width:80px"> </td>
<td>&nbsp;</td>
</tr>
</table>
</form>
</td>
</tr>
<tr>
<td align="center" valign="middle" width="136" bgcolor="#EEEEDE"><a
href="/samples/d/banner/page.html"><img alt="Discover this product"
border="0" width="136" height="64" src=
"/samples/d/banner/image.jpg"></a></td>
<td bgcolor="#EEEEDE">&nbsp;</td>
<td align="right" bgcolor="#EEEEDE">
<table summary="Formatting Table: Top Navigation" cellpadding="2"
cellspacing="0" border="0" width="100%">
<tr bgcolor="#EEEEDE">
<td valign="top" bgcolor="#EEEEDE" width="16%"><a href=
"/about/"><span class="topnav">About Us</span></a><br>
<a class="topnav1" href="/about/overview/">Overview</a><br>
<a class="topnav1" href="/about/location/">Getting here</a><br>
<a class="topnav1" href="/about/committees/">Committees</a> </td>
<td valign="top" bgcolor="#EEEEDE" width="16%"><a href=
"/products/"><span class="topnav">Products</span></a><br>
<a class="topnav1" href="/products/forecasts/">Forecasts</a><br>
<a class="topnav1" href="/products/data/">Order Data</a><br>
<a class="topnav1" href="/products/data/software/">Order
Software</a><br>
</td>
<td valign="top" bgcolor="#EEEEDE" width="16%"><a href=
"/services/"><span class="topnav">Services</span></a><br>
<a class="topnav1" href="/services/computing/">Computing</a><br>
<a class="topnav1" href="/services/archive/">Archive</a><br>
<a class="topnav1" href="/services/prepifs/">PrepIFS</a><br>
</td>
<td valign="top" bgcolor="#EEEEDE" width="16%"><a href=
"/research/"><span class="topnav">Research</span></a><br>
<a class="topnav1" href="/research/ifs/">Modelling</a><br>
<a class="topnav1" href="/research/era/">Reanalysis</a><br>
<a class="topnav1" href="/research/seasonal/">Seasonal</a><br>
</td>
<td valign="top" bgcolor="#EEEEDE" width="16%"><a href=
"/publications/"><span class="topnav">Publications</span></a><br>
<a class="topnav1" href=
"/publications/newsletters/">Newsletters</a><br>
<a class="topnav1" href="/publications/manuals/">Manuals</a><br>
<a class="topnav1" href="/publications/manuals/libraries">Libraries</a><br>
</td>
<td valign="top" bgcolor="#EEEEDE" width="20%"><a href=
"/newsevents/"><span class="topnav">News&amp;Events</span></a><br>
<a class="topnav1" href="/newsevents/calendar/">Calendar</a><br>
<a class="topnav1" href="/newsevents/employment/">Employment</a><a
class="topnav1" href="/newsevents/calendar/"></a><br>
<a class="topnav1" href="/newsevents/itt/">Open Tenders</a><br>
</td>
</tr>
</table>
</td>
</tr>
<tr>
<td align="left" valign="middle" width="136" bgcolor="#CCCE9B">
<!-- #BeginEditable "spare1" -->&nbsp;<!-- #EndEditable --></td>
<td bgcolor="#CCCE9B">&nbsp;</td>
<td valign="middle" bgcolor="#CCCE9B">
<table summary="Formatting Table: Location header" cellpadding="0"
cellspacing="0" border="0" width="100%">
<tr>
<td align="left"><span class="location">
<!-- #BeginEditable "location" -->
<!-- #BeginLibraryItem "/PRODUCTS/DATA/LIBRARY/software_top_menu.lbi" --><span
class="location"><a href="/">Home</a>&nbsp;&gt;&nbsp;
<a href= "/publications/index.html">Publications</a>&nbsp;&gt;&nbsp;
<a href= "/publications/manuals/index.html">Manuals</a> &gt;
<!-- #EndLibraryItem -->Grib API&gt;&nbsp;
<!-- #EndEditable -->&nbsp;</span> </td>
<td align="right"><!-- #BeginEditable "topprevnext" -->
<!-- #EndEditable --></td>
</tr>
</table>
</td>
</tr>
<tr>
<td align="left"><!-- #BeginEditable "spare2" -->&nbsp;
<!-- #EndEditable --> </td>
<td>&nbsp;</td>
<td align="left">
<h1><!-- #BeginEditable "heading" -->
<!-- #EndEditable --></h1>
</td>
</tr>
<tr>
<td valign="top" width="136" background=
"/assets/images/map_backdrop.jpg"><!-- #BeginEditable "submenu" -->
<!-- #BeginLibraryItem "/PRODUCTS/DATA/SOFTWARE/" --><!-- + + + + + NAME = [Data]+ + + + + + + + + -->
<table background="/assets/shim.gif" bgcolor="#FFF1B3" border="0"
cellpadding="1" cellspacing="0" width="100%" class="submenu">
<tbody>
<tr>
<td><a class="menuheading" href=
"/publications/manuals/grib_api/index.html">GRIB API Manual</a> </td>
</tr>
<tr>
<td>
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0"
width="100%">
<tr>
<td>
<table bgcolor="#ffffff" width="100%">
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/installation.html">Installation</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/namespacegribapi.html">Python</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/namespacegrib__api.html">Fortran 90</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/modules.html">C</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/conversion.html">GRIB Conversion</a></td>
</tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/gribexkeys/callGribex.html">GRIBEX keys</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/keys.html">Keys</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/grib_examples.html">Examples</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/grib_api/tools.html">Tools</a></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</tbody>
</table>
<br>
<!-- - - NAME = [archive]- - - - - - - -->
<!-- #EndLibraryItem --><!-- #BeginLibraryItem "/products/data/Library/software_rel6.lbi" --><!-- + + + + + NAME = [Data]+ + + + + + + + + -->
<!-- #BeginLibraryItem "/PRODUCTS/DATA/LIBRARY/software_menu.lbi" --><!-- + + + + + NAME = [Data]+ + + + + + + + + -->
<table background="/assets/shim.gif" bgcolor="#FFF1B3" border="0"
cellpadding="1" cellspacing="0" width="100%" class="submenu">
<tbody>
<tr>
<td><a class="menuheading" href=
"/products/data/software/index.html">Software</a> </td>
</tr>
<tr>
<td>
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0"
width="100%">
<tr>
<td>
<table bgcolor="#ffffff" width="100%">
<tr>
<td><a class="menuitem" href=
"/products/data/software/bufr.html">BUFR</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/crex.html">CREX</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/grib.html">GRIBEX</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/grib_api.html">GRIB API</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/interpolation.html">Interpolation</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/magics.html">Magics</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/metview.html">Metview</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/sms.html">SMS</a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/forms/ECMWF_software_ordering_form.pdf">Ordering
forms</a> <img src="/products/data/archive/forms/pdf.gif" width=
"20" height="20"></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/forms/ECMWF_software_licence.pdf">Software
licence<img src="/products/data/archive/forms/pdf.gif" width="20"
height="20" border="0"></a></td>
</tr>
<tr>
<td><a class="menuitem" href=
"/products/data/software/payment.html">Payment rules</a></td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</tbody>
</table>
<br>
<!-- - - NAME = [archive]- - - - - - - -->
<!-- #EndLibraryItem --><!-- #BeginLibraryItem "/products/data/Library/software_rel6.lbi" --><!-- + + + + + NAME = [Data]+ + + + + + + + + -->
<table background="/assets/shim.gif" bgcolor="#CCCE9B" border="0"
cellpadding="1" cellspacing="0" width="100%" class="submenu">
<tbody>
<tr>
<td><span><a class="menuheading" href=
"/publications/manuals/index.html">Related Manuals</a></span></td>
</tr>
<tr>
<td></td>
</tr>
<tr>
<td>
<table bgcolor="#ffffff" border="0" cellpadding="3" cellspacing="0"
width="100%">
<tr>
<td>
<table bgcolor="#ffffff" width="100%">
<tr>
<td><a class="menuitem" href=
"/publications/manuals/libraries/gribex/index.html">GRIBEX
manual</a> </td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/libraries/interpolation/index.html">Interpolation
manual</a> </td>
</tr>
<tr>
<td><a class="menuitem" href=
"/publications/manuals/metview/index.html">Metview Manuals</a></td>
</tr>
<tr>
<td>
<p><a class="menuitem" href=
"/publications/manuals/magics/index.html">Magics Manuals</a></p>
</td>
</tr>
</table>
</td>
</tr>
</table>
</td>
</tr>
</tbody>
</table>
<br>
<!-- - - NAME = [data]- - - - - - - --> <!-- #EndLibraryItem -->
<!-- #EndEditable --> &nbsp;<br>
</td>
<td>&nbsp;</td>
<td valign="top">
<!-- #BeginEditable "content" -->
<table border="3">
<caption><strong>Latitude/longitude or equidistant cylindrical
or plate carree grids </strong></caption><tbody>
<tr>
<th> Element </th>
<th> Contents </th>
<th style="vertical-align: middle;">
GRIB API keys<br>
</th>
</tr>
<tr>
<td> 1 </td>
<td>Data representation type (see <a
href="/publications/manuals/d/gribapi/fm92/grib1/show/ctables/">WMO code table 6</a>) </td>
<th style="vertical-align: top;"><div align="left"><a href="/publications/manuals/d/gribapi/keys/grids/">gridType</a><br>
</div></th>
</tr>
<tr>
<td> 2 </td>
<td> Number of points along a parallel (Ni). </td>
<th style="vertical-align: top;"><div align="left">
<p>Ni <br>
Nx <br>
</p>
</div></th>
</tr>
<tr>
<td> 3 </td>
<td> Number of points along a meridian (Nj). </td>
<th style="vertical-align: top;"><div align="left">
<p>Nj<br>
Ny<br>
</p>
</div></th>
</tr>
<tr>
<td> 4 </td>
<td> Latitude of the first grid point. </td>
<th style="vertical-align: top;"><div align="left">latitudeOfFirstGridPointInDegrees*1000</div></th>
</tr>
<tr>
<td height="136"> 5 </td>
<td> Longitude of the first grid point. </td>
<th style="vertical-align: top;"><div align="left">longitudeOfFirstGridPointInDegrees*1000</div></th>
</tr>
<tr>
<td> 6 </td>
<td>
<pre>Resolution flag:<br> 0 Direction increments not given. <br> 128 Direction increments given.<br></pre>
</td>
<th style="vertical-align: top;"><div align="left">ijDirectionIncrementGiven*128<br>
</div></th>
</tr>
<tr>
<td> 7 </td>
<td> Latitude of the last grid point. </td>
<th style="vertical-align: top;"><div align="left">latitudeOfLastGridPointInDegrees*1000</div></th>
</tr>
<tr>
<td height="42"> 8 </td>
<td> Longitude of the last grid point. </td>
<th style="vertical-align: top;"><div align="left">longitudeOfLastGridPointInDegrees*1000</div></th>
</tr>
<tr>
<td> 9 </td>
<td> i direction increment. </td>
<th style="vertical-align: top;"><div align="left">iDirectionIncrementInDegrees*1000<br>
</div></th>
</tr>
<tr>
<td> 10 </td>
<td> j direction increment. </td>
<th style="vertical-align: top;"><div align="left">jDirectionIncrementInDegrees*1000<br>
</div></th>
</tr>
<tr>
<td> 11 </td>
<td> Scanning mode flags (see <a
href="/publications/manuals/d/gribapi/fm92/grib1/show/ctables/">WMO
code table 8</a>) </td>
<th style="vertical-align: top;">
<p align="left">iScansNegatively</p>
<p align="left">jScansNegatively</p>
<p align="left">jPointsAreConsecutive</p>
<p align="left"><br>
</p>
</th>
</tr>
<tr>
<td> 12 </td>
<td> Number of vertical coordinate parameters. </td>
<th style="vertical-align: top;"><div align="left">NV<br>
</div></th>
</tr>
<tr>
<td> 13 </td>
<td> Latitude of the southern pole of rotation. </td>
<th style="vertical-align: top;"><div align="left">latitudeOfSouthernPoleInDegrees*1000<br>
</div></th>
</tr>
<tr>
<td> 14 </td>
<td> Longitude of the southern pole of rotation. </td>
<th style="vertical-align: top;"><div align="left">longitudeOfSouthernPoleInDegrees*1000<br>
</div></th>
</tr>
<tr>
<td> 15 </td>
<td> Latitude of the pole of stretching. </td>
<th style="vertical-align: top;"><div align="left">latitudeOfPoleOfStretchingInDegrees
*1000 </div></th>
</tr>
<tr>
<td> 16 </td>
<td> Longitude of the pole of stretching. </td>
<th style="vertical-align: top;"><div align="left">longitudeOfPoleOfStretchingInDegrees
*1000 </div></th>
</tr>
<tr>
<td> 17 </td>
<td><pre>0 Regular grid.<br>1 Quasi-regular (reduced) grid.<br>At the moment, quasi-regular (reduced) latitude/longitude grids are<br>not unambiguously defined. The resolution flag field indicates whether<br>or not both direction increments are given; at least one must be given,<br>as grids are only allowed to be irregular in one direction.<br></pre>
</td>
<th style="vertical-align: top;"><div align="left"><a href="/publications/manuals/d/gribapi/keys/grids/">gridType</a><br>
</div></th>
</tr>
<tr>
<td> 18 </td>
<td><pre>Earth flag:<br> 0 Earth assumed spherical with radius 6367.47 km.<br> 64 Earth assumed oblate spheroidal with size as determined by IAU in 1965:<br> 6378.160km, 6356.775km, f=1/297.0</pre>
</td>
<th style="vertical-align: top;"><div align="left">earthIsOblate<br>
</div></th>
</tr>
<tr>
<td> 19 </td>
<td>
<pre>Components flag:<br> 0 Resolved u and v components of vector quantities relative to easterly<br> and northerly directions.<br> 8 Resolved u and v components of vector quantities relative to the<br> defined grid in the direction of increasing x and y (or i and j)<br> coordinates respectively.<br></pre>
</td>
<th style="vertical-align: top;"><div align="left">uvRelativeToGrid<br>
</div></th>
</tr>
<tr>
<td> 20-22 </td>
<td> Reserved. Set to 0. </td>
<th style="vertical-align: top;"><div align="left"><br>
</div></th>
</tr>
<tr>
<td> 23-nn </td>
<td>
<pre>For a quasi-regular (reduced) grid, the number of points along each parallel<br>must be defined. The number of parallels is given by Nj above.<br>Alternatively, this may be the number of pointqs along each meridian, where<br>the number of meridians is given by Ni above.q<br></pre>
</td>
<th style="vertical-align: top;"><div align="left">pl<br>
</div></th>
</tr>
</tbody>
</table>
<!-- #EndEditable --><br>
<!-- #BeginEditable "related" --> &nbsp; <!-- #EndEditable -->
<br>
<br>
</td>
</tr>
<tr>
<td bgcolor="#CCCE9B" valign="baseline">
<table summary="Formatting Table: date footer" height="16" border=
"0" cellspacing="0" cellpadding="0">
<tr>
<td><a href="#top"><img src="/assets/icons/up.gif" alt=
"Top of page" border="0" width="18" height="18"></a></td>
<td><span class="documentdate"><!-- #BeginEditable "version" --><!-- #BeginDate format:Ge1 -->22.10.2010<!-- #EndDate -->-->
<!-- #EndEditable --></span></td>
</tr>
</table>
</td>
<td valign="middle" bgcolor="#CCCE9B">&nbsp;</td>
<td bgcolor="#CCCE9B" align="right" valign="baseline">
<table summary="Formatting table: main footer" width="100%" border=
"0" cellspacing="0" cellpadding="0">
<tr align="right">
<td align="left"><span class="info">
<!-- #BeginEditable "info" -->&nbsp;&nbsp;
<!-- #EndEditable --></span></td>
<td bgcolor="#CCCE9B"><span class="editor"><a href=
"/tools/detailer/"><img alt="Page Details" src=
"/assets/icons/detailer.gif" border="0" width="18" height="18"></a>
<!-- #BeginEditable "editor" -->&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<!-- #EndEditable --></span></td>
<td bgcolor="#CCCE9B"><span class="copyright"><a href=
"/frontpage/copyright/">&copy; ECMWF</a></span> </td>
<td><!-- #BeginEditable "botprevnext" --><!-- #EndEditable --></td>
</tr>
</table>
</td>
</tr>
<tr>
<td height="1" width="136" bgcolor="#CCCB9E"><img alt="shim"
height="1" width="136" src="/assets/shim.gif"></td>
<td height="1" width="008" bgcolor="#CCCB9E"><img alt="shim"
height="1" width="8" src="/assets/shim.gif"></td>
<td height="1" width="100%" bgcolor="#CCCB9E"><img alt="shim"
height="1" width="160" src="/assets/shim.gif"></td>
</tr>
</table>
</body>
<!-- #EndTemplate -->
</html>