Kurt, Even,
Progress! Check this out:
http://imaptools.com:8080/demo/tiger-hycom.html?zoom=8&lat=31.42299&lon=-79.78765&layers=BTT
I tweaked your script, to copy both the water_u and water_v as separate
bands (so back to 80 bands), I actually only need a few depths so
eventually I'll cut that down.
If you zoom out there are lots of blank areas with no currents. I'm not
sure if this is normal or what.
https://gist.github.com/woodbri/ad0984675b17c45739dbb592bde6639a#file-hycom_uv_netcdf_to_uv_gtiff-py
Here are the mapfile bits:
https://gist.github.com/woodbri/ad0984675b17c45739dbb592bde6639a#file-mapfile-for-hycom-ocean-currents-map
Thanks for the help!
-Steve
On 6/6/2016 2:29 PM, Stephen Woodbridge wrote:
On 6/6/2016 1:25 PM, Kurt Schwehr wrote:
+gdal-dev
Some hackish test code I had laying around from last year...
https://gist.github.com/schwehr/01f6604afc7757ea0a676f0eb28be582
Thank you! I have it running, so next I'll play with the code.
You might also be able to just write 80 layers of u-v, pick out pairs
for each depth layer and have the rendering system do the
conversion(s). You could use whatever you want once you have a
geotiff. In this screenshot, I made an 80-layer geotiff of u and v
alternating layers and uploaded that to Earth Engine. It's been a long
time since I heavily used mapserver, but you could probably do the same
there.
https://www.flickr.com/photos/schwehr/26895009754/
Very cool picture!
This really helps to get me started.
Thanks,
-Steve
On Mon, Jun 6, 2016 at 7:51 AM, Stephen Woodbridge
<wood...@swoodbridge.com <mailto:wood...@swoodbridge.com>> wrote:
On 6/5/2016 2:04 PM, Kurt Schwehr wrote:
Stephen,
Take a look at these two discussions for starters on working
with hycom:
http://gis.stackexchange.com/questions/167155/how-can-i-make-geotiffs-of-individual-depth-layers-in-the-hycom-ocean-circulatio
Hi Kurt,
In the link above you mention:
I've got some code written the does things like calculate the
speed
inm/s from the UV and creates a geotiff, etc
Can you share this code, it sounds like exactly what I need for the
current vectors? And I'm interested in figuring out how to
read/write and work with the netcdf files.
I think for now I'll work with the "u" datasets as they seem that
they will be much easier place to start.
Thanks,
-Steve
http://gis.stackexchange.com/questions/170882/how-can-a-make-a-netcdf-with-subgroups-smaller
You should start with the regular grids. e.g.
ftp://ftp.hycom.org/datasets/GLBu0.08/expt_91.1/data/hindcasts/2015/hycom_glb_911_2015093000_t000_uv3z.nc
Make an 80 layer geotiff from the u/v and then use mapserver
as Even
suggested.
-kurt
On Sat, Jun 4, 2016 at 6:29 AM, Even Rouault
<even.roua...@spatialys.com <mailto:even.roua...@spatialys.com>
<mailto:even.roua...@spatialys.com
<mailto:even.roua...@spatialys.com>>> wrote:
Hi,
>
> I want to convert some HYCOM data into GTiff format and
I'm a little
> lost on how to get started, whether I can do what I need
just using a
> vrt or if I'm going to have to write code to process the
data.
>
> To start with I have placed gdalinfo on one file here:
> http://imaptools.com:8080/dl/hycom-gdalinfo.txt
>
> The data comes from
http://hycom.org/dataserver/glb-analysis
> and I will need to be using GLBa0.08 dataset.
>
> I have two use cases:
>
> 1) The simple one is to extract say Band 1 into a
georeferenced GTiff
> and apply color to using color ranges without loosing the
NODATA. I
> think I can do later using .vrt, correct?
gdaldem color-relief can output to a VRT, but given that
this netCDF
file is
georeferenced through a geolocation array, you'll likely
have first
to run
gdalwarp -geoloc to have something useful at the end.
>
> I'm not sure how to deal with the georeferencing, because
the download
> site says: "Native hycom .[ab] data converted to NetCDF on
native
> Mercator-curvilinear HYCOM horizontal grid" but that does
not seem in
> sync with the Metadata in the file.
>
> 2) The more complicated case is that there are two files:
> a) eastward_sea_water_velocity (aka: u, u-velocity)
> b) northward_sea_water_velocity (aka: v, v-velocity)
> that I would like to use to create a grid of vectors with
arrowheads
> using u and v to define the vector and where the color of
the vector is
> related to the magnitude of its length. Ultimately this
data will get
> rendered via mapserver so I'm wondering if I can do this
via a GTiff or
> if I will have to resort to creating a massive point
shapefile with
> attributes of angle and magnitude and use a symbol. It
seems like it
> would be best if I can keep the data as a GTiff and then
sample the
> points and render the vectors on the fly for when you zoom
in/out.
See
http://mapserver.org/input/vector/vector_field.html
You don't need to create a vector file.
You'll have to preprocess your file to get the u and v bands
in the same
raster.
Even
--
Spatialys - Geospatial professional services
http://www.spatialys.com
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org <mailto:gdal-dev@lists.osgeo.org>
<mailto:gdal-dev@lists.osgeo.org
<mailto:gdal-dev@lists.osgeo.org>>
http://lists.osgeo.org/mailman/listinfo/gdal-dev
--
--
http://schwehr.org
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
--
--
http://schwehr.org
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/gdal-dev
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
_______________________________________________
gdal-dev mailing list
gdal-dev@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/gdal-dev
