[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

[THREDDS #EAF-567984]: ncWMS GetMetadata: doesn't handle longitudes on 0-360 scale for irregular grids



Hi John,

I'm CCing Jon Blower on this to see what he thinks.

Ethan

John Maurer wrote:
> Hi TDS/ncWMS support,
> I use ncWMS GetMetadata calls to retrieve min and max data values for a
> given lat/lon bounding box in our Google Maps API. In order to skirt issues
> when spanning the dateline, I put longitudes on a scale of 0 to 360 rather
> than -180 to +180 to avoid an "invalid bounding box" error that occurs when
> the minimum longitude is positive and the maximum longitude is negative.
> While this works for many of our datasets, it returns null min/max values if
> the dataset is on an irregular grid (specifically curvilinear in our cases).
> Perhaps this scenario was overlooked and is a small bug in ncWMS? Here are
> some examples:
> 
> BBOX on 0-360 scale:
> 200.9783935546875,20.662341103925662,203.31985473632812,21.637005211106306
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec/hiog/ROMS_Oahu_Regional_Ocean_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=temp&BBOX=200.9783935546875,20.662341103925662,203.31985473632812,21.637005211106306&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z&ELEVATION=-0.016666666666666666
> 
> {"min":"","max":""}
> 
> Similar BBOX on -180 to +180 scale:
> 160.191650390625,20.174567450431844,-155.50872802734375,22.12381042563998
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec/hiog/ROMS_Oahu_Regional_Ocean_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=temp&BBOX=-160.191650390625,20.174567450431844,-155.50872802734375,22.12381042563998&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z&ELEVATION=-0.016666666666666666
> 
> {"min":25.126493,"max":26.430931}
> 
> Here are examples that span the dateline, to illustrate why I need to use
> the 0-360 scale:
> 
> BBOX on -180 to +180 scale gives invalid bounding box error:
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec/hiog/ROMS_Oahu_Regional_Ocean_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=temp&BBOX=164.6630859375,4.959615024698026,-120.41015624999999,35.817813158696616&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z&ELEVATION=-0.016666666666666666
> 
> {"exception":{"className":"uk.ac.rdg.resc.ncwms.exceptions.WmsException","message":"Invalid
> bounding box format"}}
> 
> But again, a similar BBOX on 0-360 scale returns null for a curvilinear
> dataset:
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec/hiog/ROMS_Oahu_Regional_Ocean_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=temp&BBOX=164.6630859375,4.12728532324537,239.58984375,35.137879119634185&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z&ELEVATION=-0.016666666666666666
> 
> {"min":"","max":""}
> 
> Just to prove that it works for regular gridded datasets, here are a couple
> URLs on 0-360 scale that work:
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/model/wav/swan/oahu/SWAN_Oahu_Regional_Wave_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=shgt&BBOX=201.4391326904297,21.231782183740147,202.60986328125,21.718041902388794&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z
> 
> {"min":0,"max":1.9349945}
> 
> http://oos.soest.hawaii.edu/thredds/wms/hioos/model/atm/ncep_global/NCEP_Global_Atmospheric_Model_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMetadata&item=minmax&LAYERS=tmp2m&BBOX=0,-78.9039293885709,360,78.97138592818217&CRS=EPSG:4326&WIDTH=1705&HEIGHT=761&TIME=2011-07-20T21:00:00Z
> 
> {"min":215.5,"max":321}
> 
> Thanks for giving this a look!
> Cheers,
> John Maurer
> Pacific Islands Ocean Observing System (PacIOOS)
> University of Hawaii at Manoa



Ticket Details
===================
Ticket ID: EAF-567984
Department: Support THREDDS
Priority: High
Status: Open


NOTE: All email exchanges with Unidata User Support are recorded in the Unidata inquiry tracking system and then made publicly available through the web. If you do not want to have your interactions made available in this way, you must let us know in each email you send to us.