I found a fix and a way to apply it as a temporary hack. Basically what happens
is the following:
- In Grib2CollectionBuilder.Grib2Rectilyser.make unique coordinate systems are
built from the various PDS sections
- The PDS' data sections are collected into VariableBags
- To determine which coordinates are used the vertical height unit is examined,
among others
- This unit is (usually) provided by the Grib2Customizer (an implementation of
GribTables)
- The current implementation lacks a switch-case for code 150 (generalized
vertical height) and the default mapping defines the unit as 'null'
- From this it is determined that no vertical coordinate is present
- Thus the coordinate is missing and the builder builds the coordinate system
without the height coordinate
- In the end most of the data is missing because the later data sections
overwrite the earlier ones, as one of their distinguishing dimensions is missing
The fix is quite simple: all I did was adding case statements for code 150 in
Grib2Customizer.getVertUnit(int) and Grib2Customizer.getLevelNameShort(int). A
patch is attached below.
For those who stumble over this and don't have access to a patched version, you
can derive a class from Grib2Customizer and override the two offending methods.
Then set a private variable of Grib2Customizer via reflection like shown below.
I recommend doing this in a static block.
Field f = Grib2Customizer.class.getDeclaredField("wmoStandardTable");
f.setAccessible(true);
f.set(null, MyGrib2Customizer.factory(0, -1, -1, -1, -1));
Cheers,
~
Patch:
====
--- ucar/nc2/grib/grib2/table/Grib2Customizer.java.orig 2016-12-05
17:44:09.663099300 +0100
+++ ucar/nc2/grib/grib2/table/Grib2Customizer.java.patched 2016-12-05
17:45:16.147099300 +0100
@@ -408,6 +408,9 @@
case 119:
return new GribLevelType(code, "Pa", null, false); // ??
+ case 150:
+ return new GribLevelType(code, "numeric", null, true);
+
case 160:
return new GribLevelType(code, "m", "sea level", false);
@@ -505,6 +508,8 @@
return "hybrid_pressure";
case 120:
return "pressure_thickness";
+ case 150:
+ return "generalized_vertical_height";
case 160:
return "depth_below_sea";
case GribNumbers.UNDEFINED:
