mirror of https://github.com/ecmwf/eccodes.git
755 lines
25 KiB
HTML
755 lines
25 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"> </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> </td>
|
|
<td><a href="/your/d/room/" class="menuitem">Your Room</a></td>
|
|
<td> </td>
|
|
<td><a href="/tools/login/" class="menuitem">Login</a></td>
|
|
<td> </td>
|
|
<td><a href="/about/contact/" class="menuitem">Contact</a></td>
|
|
<td> </td>
|
|
<td><a href="/about/feedback/" class="menuitem">Feedback</a></td>
|
|
<td> </td>
|
|
<td><a href="/about/sitemap/" class="menuitem">Site Map</a></td>
|
|
<td> </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> </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"> </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&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" --> <!-- #EndEditable --></td>
|
|
<td bgcolor="#CCCE9B"> </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> >
|
|
<a href= "/publications/index.html">Publications</a> >
|
|
<a href= "/publications/manuals/index.html">Manuals</a> >
|
|
<!-- #EndLibraryItem -->Grib API>
|
|
<!-- #EndEditable --> </span> </td>
|
|
<td align="right"><!-- #BeginEditable "topprevnext" -->
|
|
<!-- #EndEditable --></td>
|
|
</tr>
|
|
</table>
|
|
</td>
|
|
</tr>
|
|
|
|
<tr>
|
|
<td align="left"><!-- #BeginEditable "spare2" -->
|
|
<!-- #EndEditable --> </td>
|
|
<td> </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 --> <br>
|
|
</td>
|
|
<td> </td>
|
|
<td valign="top">
|
|
|
|
|
|
<!-- #BeginEditable "content" -->
|
|
<style type="text/css">
|
|
<!--
|
|
.style1 {color: #FF0000}
|
|
-->
|
|
</style>
|
|
<h2>GRIB section 4, the binary data section</h2>
|
|
An INTEGER array of at least 42 elements.
|
|
<p>
|
|
<table border="3">
|
|
<caption>
|
|
<strong>Contents of KSEC4</strong>
|
|
</caption> <tbody>
|
|
<tr>
|
|
<th> Element </th>
|
|
<th> Contents </th>
|
|
<th> GRIB API keys<br>
|
|
</th>
|
|
</tr>
|
|
<tr>
|
|
<td> 1 </td>
|
|
<td> Number of data values in array PSEC4 to be encoded or
|
|
which have been decoded. When the 'A' coding option is used, the count
|
|
is the number of image bytes stored four to an integer. When the 'B'
|
|
coding option is used, the count is the number of integers used to
|
|
return image bytes, stored four to an integer.
|
|
<p> When a bitmap is used, this number includes the total
|
|
of both missing and present data values. </p>
|
|
<p> If this number is negative: </p>
|
|
<li> the number of field points is -KSEC4(1), </li>
|
|
<li> the entire field is missing, </li>
|
|
<li> all values in PSEC4 are 0, </li>
|
|
<li> the coded data has all the bits of its scale factor
|
|
are set to 1 </li>
|
|
<li> all the bits of the exponent and mantissa of its
|
|
reference value are set to 1 (This is an ECMWF convention). </li>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left">
|
|
<p>numberOfPoints</p>
|
|
<p>numberOfValues</p>
|
|
<p>numberOfCodedValues</p>
|
|
<p>numberOfMissing<br>
|
|
</p>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 2 </td>
|
|
<td> Number of bits used for each encoded value. </td>
|
|
<th style="vertical-align: top;"><div align="left">
|
|
<p>decimalPrecision</p>
|
|
<p>bitsPerValue</p>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 3 </td>
|
|
<td>
|
|
<pre>Type of data:<br> 0 Grid point data.<br> 128 Spherical harmonic coefficients<br> (Used only if Section 2 is not included when <br> coding data.)</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> 4 </td>
|
|
<td>
|
|
<pre>Type of packing:<br> 0 Simple packing.<br> 64 Complex or second-order packing.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left">packingType =<span class="style1">
|
|
grid_simple | grid_ieee | spectral_complex | spectral_simple | <br>
|
|
spectral_ieee | grid_simple_matrix | grid_second_order | <br>
|
|
grid_second_order_different_width | grid_complex | <br>
|
|
grid_complex_spatial_differencing | grid_jpeg | grid_png | <br>
|
|
grid_simple_log_preprocessing<br>
|
|
</span><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 5 </td>
|
|
<td>
|
|
<pre>Data representation:<br> 0 Floating point data.<br> 32 Integer data.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 6 </td>
|
|
<td>
|
|
<pre>Additional flags indicator:<br> 0 No additional flags.<br> 16 Additional flags.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 7 </td>
|
|
<td> Reserved. Set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 8 </td>
|
|
<td>
|
|
<pre>Number of values indicator:<br> 0 Single datum at each grid point.<br> 64 Matrix of values at each grid point.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 9 </td>
|
|
<td>
|
|
<pre>Secondary bitmaps indicator:<br> 0 No secondary bitmaps.<br> 32 Secondary bitmaps present.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 10 </td>
|
|
<td>
|
|
<pre>Values width indicator:<br> 0 Second order values have constant width.<br> 16 Second order values have different widths.<br></pre>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 11 </td>
|
|
<td> Number of bits for second order values when these have
|
|
constant width. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 12-15 </td>
|
|
<td> Reserved for WMO reserved flag fields. Set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 16 </td>
|
|
<td> For complex packing, a pointer to the start of packed
|
|
data values (ie the octet number). Otherwise set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 17 </td>
|
|
<td> For complex packing, the scaling factor P, stored as
|
|
the INTEGER value P*1000 (in the range -10000 to +10000). Otherwise set
|
|
to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 18 </td>
|
|
<td> For complex packing, the pentagonal resolution
|
|
parameter J specifying the truncation of the subset of the data
|
|
represented as 32-bit floating point numbers (ie not packed). Otherwise
|
|
set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 19 </td>
|
|
<td> For complex packing, the pentagonal resolution
|
|
parameter K specifying the truncation of the subset of the data
|
|
represented as 32-bit floating point numbers (ie not packed). Otherwise
|
|
set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 20 </td>
|
|
<td> For complex packing, the pentagonal resolution
|
|
parameter M specifying the truncation of the subset of the data
|
|
represented as 32-bit floating point numbers (ie not packed). Otherwise
|
|
set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 21 </td>
|
|
<td> The number of non-missing values in a field which uses
|
|
a bitmap.
|
|
<p>When the 'B' coding option is used, this count is the
|
|
number of image bytes
|
|
(versions of GRIBEX after 13.040). </p>
|
|
</td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 22-33 </td>
|
|
<td> Reserved. Set to 0. </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
<tr>
|
|
<td> 34 </td>
|
|
<td> An offset bit pointer to coded values in the GRIB
|
|
record. (This is returned by the 'G', 'I' or 'J' decoding options). </td>
|
|
<th style="vertical-align: top;"><div align="left"><br>
|
|
</div></th>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</p>
|
|
<h2>X decoding option.</h2>
|
|
Elements 34 to 42 are used only for the 'X' option, which decodes up to
|
|
4 values. (See HOPER above). The scanning mode must be from West to
|
|
East and from North to South.
|
|
<table border="3">
|
|
<caption><strong> KSEC4 - X decoding option </strong></caption><tbody>
|
|
<tr>
|
|
<th> Element </th>
|
|
<th> Contents </th>
|
|
</tr>
|
|
<tr>
|
|
<td> 34 </td>
|
|
<td> Number of points to be decoded (maximum 4). </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 35 </td>
|
|
<td> Number of the latitude row of the first value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 36 </td>
|
|
<td> Number of the longitude point of the first value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 37 </td>
|
|
<td> Number of the latitude row of the second value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 38 </td>
|
|
<td> Number of the longitude point of the second value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 39 </td>
|
|
<td> Number of the latitude row of the third value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 40 </td>
|
|
<td> Number of the longitude point of the third value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 41 </td>
|
|
<td> Number of the latitude row of the fourth value. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 42 </td>
|
|
<td> Number of the longitude point of the fourth value. </td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<h2>Grid point matrix packing.</h2>
|
|
For grid point packing, with a matrix of values at each grid point,
|
|
elements 50 to (50+NC1+NC2) are used as follows:
|
|
<table border="3">
|
|
<caption><strong> KSEC4 - grid matrix packing </strong></caption><tbody>
|
|
<tr>
|
|
<th> Element </th>
|
|
<th> Contents </th>
|
|
</tr>
|
|
<tr>
|
|
<td> 50 </td>
|
|
<td> First dimension of each matrix (the number of rows). </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 51 </td>
|
|
<td> Second dimension of each matrix (the number of
|
|
columns). </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 52 </td>
|
|
<td> First dimension coordinate values definition. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 53 </td>
|
|
<td> Number of coefficients or values used to specify the
|
|
first dimension coordinate function, NC1. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 54 </td>
|
|
<td> Second dimension coordinate values definition. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 55 </td>
|
|
<td> Number of coefficients or values used to specify the
|
|
second dimension coordinate function, NC2. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 56 </td>
|
|
<td> First dimension physical significance. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 57 </td>
|
|
<td> Second dimension physical significanc. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> 58 - 59 </td>
|
|
<td> Reserved. Set to 0. </td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
<h2>ECMWF use of REALs.</h2>
|
|
In the WMO specification, the following fields are INTEGER values.
|
|
ECMWF uses floating-point values for its wave models, so these fields
|
|
contain REAL values in both input and output.
|
|
<table border="3">
|
|
<caption><strong> KSEC4 - ECMWF use of REALs </strong></caption><tbody>
|
|
<tr>
|
|
<th> Elements </th>
|
|
<th> Contents </th>
|
|
</tr>
|
|
<tr>
|
|
<td> 60 - (59+NC1) </td>
|
|
<td> Coefficients to define the first dimension coordinate
|
|
values in functional form, or the explicit coordinate values. </td>
|
|
</tr>
|
|
<tr>
|
|
<td> (60+NC1)-(59+NC1+NC2) </td>
|
|
<td> Coefficients to define the second dimension coordinate
|
|
values in functional form, or the explicit coordinate values </td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
|
|
|
|
|
|
<!-- #EndEditable --><br>
|
|
<!-- #BeginEditable "related" --> <!-- #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"> </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" -->
|
|
<!-- #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" --> <!-- #EndEditable --></span></td>
|
|
<td bgcolor="#CCCE9B"><span class="copyright"><a href=
|
|
"/frontpage/copyright/">© 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>
|
|
|