From 31efe677b40fe491c988d50f96b59b1b7e2d46f7 Mon Sep 17 00:00:00 2001
From: lassulus <lassulus@lassul.us>
Date: Wed, 11 Dec 2019 20:44:21 +0100
Subject: Initial commit

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+grib2json
+=========
+
+A command line utility that decodes [GRIB2](http://en.wikipedia.org/wiki/GRIB) files as JSON.
+
+This utility uses the netCDF-Java GRIB decoder, part of the [THREDDS](https://github.com/Unidata/thredds) project
+by University Corporation for Atmospheric Research/Unidata.
+
+Installation
+------------
+
+```
+git clone <this project>
+mvn package
+```
+
+This creates a .tar.gz in the target directory. Unzip and untar the package in a location of choice.
+
+Usage
+-----
+
+The `grib2json` launch script is located in the `bin` directory and requires the `JAVA_HOME` environment
+variable to be defined.
+
+```
+> grib2json --help
+Usage: grib2json [options] FILE
+	[--compact -c] : enable compact Json formatting
+	[--data -d] : print GRIB record data
+	[--filter.category --fc value] : select records with this numeric category
+	[--filter.parameter --fp value] : select records with this numeric parameter
+	[--filter.surface --fs value] : select records with this numeric surface type
+	[--filter.value --fv value] : select records with this numeric surface value
+	[--help -h] : display this help
+	[--names -n] : print names of numeric codes
+	[--output -o value] : write output to the specified file (default is stdout)
+	[--verbose -v] : enable logging to stdout
+```
+
+For example, the following command outputs to stdout the records for parameter 2 (U-component_of_wind), with
+surface type 103 (Specified height level above ground), and surface value 10.0 meters from the GRIB2 file
+_gfs.t18z.pgrbf00.2p5deg.grib2_. Notice the optional inclusion of human-readable _xyzName_ keys and the data array:
+
+```
+> grib2json --names --data --fp 2 --fs 103 --fv 10.0 gfs.t18z.pgrbf00.2p5deg.grib2
+
+[
+    {
+        "header":{
+            "discipline":0,
+            "disciplineName":"Meteorological products",
+            "gribEdition":2,
+            "gribLength":27759,
+            "center":7,
+            "centerName":"US National Weather Service - NCEP(WMC)",
+            "parameterNumber":2,
+            "parameterNumberName":"U-component_of_wind",
+            "parameterUnit":"m.s-1",
+            "surface1Type":103,
+            "surface1TypeName":"Specified height level above ground",
+            "surface1Value":10.0,
+            ...
+        },
+        "data":[
+            -2.12,
+            -2.27,
+            -2.41,
+            ...
+        ]
+    }
+]
+```
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