Thanks, all! I'm surprised the ordering of coordinates changes with
projection, but I can work with that! I appreciate your responses.
Cheers,
John (Maurer)
On Mon, Apr 15, 2013 at 12:01 AM, Jon Blower <j.d.blower@xxxxxxxxxxxxx>wrote:
> **Ø **for some unfathomable reason the spec switches to
> ymin,xmin,ymax,xmax in 1.3.0 when you use CRS:84****
>
> ** **
>
> I think you mean “… when you use EPSG:4326”. CRS:84 is always x,y axis
> order. ;-)****
>
> ** **
>
> The reason is that the EPSG database uses conventions from navigation,
> which is latitude-longitude order. There was a mistake in WMS1.1.1 that
> meant that EPSG:4326 was defined with the axis order reversed. This was
> corrected in WMS 1.3.0 and a new CRS added (CRS:84) that is defined with
> longitude-latitude axis order.****
>
> ** **
>
> Thanks for those links Ivan, very helpful!****
>
> ** **
>
> Jon****
>
> ** **
>
> *From:* Ivan Price [mailto:Ivan.Price@xxxxxxxxxxx]
> *Sent:* 15 April 2013 10:18
> *To:* John Maurer; THREDDS Users; ncwms-users@xxxxxxxxxxxxxxxxxxxxx
> *Subject:* Re: [Ncwms-users] [thredds] WMS 1.3.0 blank maps using
> EPSG:4326 (but works using CRS:84)****
>
> ** **
>
> it could be the order of lat/longs is reversed in your request.****
>
> ** **
>
> for some unfathomable reason the spec switches to ymin,xmin,ymax,xmax in
> 1.3.0 when you use CRS:84****
>
> ** **
>
> see this:****
>
>
> http://viswaug.wordpress.com/2009/03/15/reversed-co-ordinate-axis-order-for-epsg4326-vs-crs84-when-requesting-wms-130-images/
> ****
>
> ** **
>
> or ncWMS specifically this:****
>
> ** **
>
>
> http://www.resc.rdg.ac.uk/trac/ncWMS/wiki/FrequentlyAskedQuestions#MyWMSclientuseslatitude-longitudeaxisorder
> ****
>
> ** **
>
> so your initial link works if you swap them around...****
>
> ** **
>
>
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec_regridded/hiig/ROMS_Hawaii_Regional_Ocean_Model_Regridded_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMap&FORMAT=image/png&TRANSPARENT=true&LAYERS=water_temp&CRS=EPSG:4326&BBOX=20.17714549791179,202.12371826171875,21.50418550077842,204.46517944335938&WIDTH=1705&HEIGHT=1034&TIME=2013-04-15T00:00:00Z&ELEVATION=-5&STYLES=boxfill/rainbow&NUMCOLORBANDS=256&COLORSCALERANGE=24.02441,26.03417
> ****
>
> ** **
>
> ** **
>
> -i****
>
> ** **
>
> ** **
>
> ** **
>
> *De :* thredds-bounces@xxxxxxxxxxxxxxxx [
> mailto:thredds-bounces@xxxxxxxxxxxxxxxx <thredds-bounces@xxxxxxxxxxxxxxxx>]
> *De la part de* John Maurer
> *Envoyé :* Saturday, 13 April 2013 02:46
> *À :* THREDDS Users; ncwms-users@xxxxxxxxxxxxxxxxxxxxx
> *Objet :* [thredds] WMS 1.3.0 blank maps using EPSG:4326 (but works using
> CRS:84)****
>
> ** **
>
> Hi TDS and/or ncWMS folks,
> I recently upgraded from TDS 4.2.10 to 4.3.16 and am noticing something
> strange in my WMS output. GetMap URL's that used to work fine in TDS 4.2.10
> are coming up blank in 4.3.16. As a workaround, I discovered that changing
> my CRS from EPSG:4326 to CRS:84 fixes the problem. Seems like a bug with
> using EPSG:4326??
>
> Here's an example using a ROMS ocean forecast of water temperature over
> central Hawaii. Using EPSG:4326 gives a blank map:
>
>
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec_regridded/hiig/ROMS_Hawaii_Regional_Ocean_Model_Regridded_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMap&FORMAT=image/png&TRANSPARENT=true&LAYERS=water_temp&CRS=EPSG:4326&BBOX=202.12371826171875,20.17714549791179,204.46517944335938,21.50418550077842&WIDTH=1705&HEIGHT=1034&TIME=2013-04-15T00:00:00Z&ELEVATION=-5&STYLES=boxfill/rainbow&NUMCOLORBANDS=256&COLORSCALERANGE=24.02441,26.03417
>
> In contrast, if I switch this to CRS:84 I now get a color map as expected:
>
>
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec_regridded/hiig/ROMS_Hawaii_Regional_Ocean_Model_Regridded_best.ncd?service=WMS&version=1.3.0&REQUEST=GetMap&FORMAT=image/png&TRANSPARENT=true&LAYERS=water_temp&CRS=CRS:84&BBOX=202.12371826171875,20.17714549791179,204.46517944335938,21.50418550077842&WIDTH=1705&HEIGHT=1034&TIME=2013-04-15T00:00:00Z&ELEVATION=-5&STYLES=boxfill/rainbow&NUMCOLORBANDS=256&COLORSCALERANGE=24.02441,26.03417
>
> Oh... And I just found another workaround. If I switch to WMS 1.1.1
> instead of 1.3.0, EPSG:4326 also works:
>
>
> http://oos.soest.hawaii.edu/thredds/wms/hioos/roms_forec_regridded/hiig/ROMS_Hawaii_Regional_Ocean_Model_Regridded_best.ncd?service=WMS&version=1.1.1&REQUEST=GetMap&FORMAT=image/png&TRANSPARENT=true&LAYERS=water_temp&SRS=EPSG:4326&BBOX=202.12371826171875,20.17714549791179,204.46517944335938,21.50418550077842&WIDTH=1705&HEIGHT=1034&TIME=2013-04-15T00:00:00Z&ELEVATION=-5&STYLES=boxfill/rainbow&NUMCOLORBANDS=256&COLORSCALERANGE=24.02441,26.03417
>
> In short, I'm hoping that somebody can fix the WMS so that EPSG:4326 will
> not give me blank maps in WMS 1.3.0, but I have workarounds in the meantime
> so it's not pressing.
> Thanks!,
> John Maurer
> Pacific Islands Ocean Observing System (PacIOOS)
> University of Hawaii at Manoa****
>
