I pushed a POC https://github.com/did-g/OpenCPN.git
in branch WIP_next
- It uses a multiple files style dialog box, use CTRL and SHIFT for selecting files.
It does interpolation so you can open a 3h wind
GRIB with 1h current
GRIB and get some display (interpolated values are often wrong and it's slow but good enough for now).
If you open files with the same record
type at the same time it will do, something..., surely stupid.
- I chainsawed stuff from qtvlm and ucar.edu for grib2, it's linux
only for now.
You have to install jasper for jpeg decoding, on debian like system:
apt-get install libjasper1
apt-get install libjasper-dev
It's slow and uses a lot of memory but it's a start, no waves or precipitation yet.
Without jasper but with libgrib-api-tools installed you can convert from jpeg to
grid_simple encoding with:
grib_set -s dataRepresentationTemplateNumber=0 src.grb dst.grb
And still open grib2 files, as a matter of fact you can convert grib2 to grib1 with
grib_set -s edition=1 src.grb dst.grb
but it's buggy and there's not always a match between v2 records type and v1 type.
If gribs are too big you can split them with:
grib_copy src.grb dst[shortName].grb
and then open only dts<whatever>.grb
10u and 10v for wind
ucurr and vcurr for current
gust for, well gust (not ugust or vgust, ocpn doesn't use them)
tcc: total cloud cover.
and so on.
- If you use Sean's weather_routing you have to clone:
Internal grib record
format is different and incompatible with older weather_routing versions.
The textbook Manche (English Channel) crossing COG example. model MeteoFrance AROME 0.025° cells and MyOcean current grib. (brown arrows are wind over water
, black wind arrows are current).