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Default time in GIBS WMS requests with time dimension

Posted: Thu Jul 29, 2021 11:39 am America/New_York
by clementjonglez
Dear all,

I am using the GIBS's OGC Web Map Service (WMS) [https://wiki.earthdata.nasa.gov/display/GIBS/GIBS+API+for+Developers#GIBSAPIforDevelopers-OGCWebMapService(WMS)] in a software which does not support time dimension.

According to the OGC WMS standard, when no time is specified, the default date should be used by the map server.

Also, according to the GIBS's getCapabilities file [https://gibs.earthdata.nasa.gov/wms/epsg4326/all/wms.cgi?SERVICE=WMS&REQUEST=GetCapabilities&VERSION=1.3.0], for the layers I am using, the default date should be the current date (or a few days before). For instance at the present time, the default date is 2021-07-27.

However, the results look very different when *manually* specifying 2021-07-27 as the time. And by comparing with FIRMS Fire Map, I am pretty sure that the default date is definitely not 2021-07-27.
For instance, below are two pictures:
* modis-no-date-specified.png: from https://gibs.earthdata.nasa.gov/wms/epsg4326/all/wms.cgi?CRS=EPSG:4326&FORMAT=image/png&LAYERS=MODIS_Combined_Thermal_Anomalies_All&REQUEST=GetMap&SERVICE=WMS&STYLES=default&VERSION=1.3.0&TRANSPARENT=true&REQUEST=GetMap&WIDTH=1024&HEIGHT=512&BBOX=-90,-180,90,180
* modis-2021-07-27: from https://gibs.earthdata.nasa.gov/wms/epsg4326/all/wms.cgi?CRS=EPSG:4326&FORMAT=image/png&LAYERS=MODIS_Combined_Thermal_Anomalies_All&REQUEST=GetMap&SERVICE=WMS&STYLES=default&VERSION=1.3.0&TRANSPARENT=true&REQUEST=GetMap&WIDTH=1024&HEIGHT=512&BBOX=-90,-180,90,180&TIME=2021-07-27
Only the second picture actually matches the wild fires on 2021-07-27.

I am using the following layers:
a. MODIS_Combined_Thermal_Anomalies_All
b. VIIRS_NOAA20_Thermal_Anomalies_375m_All
c. VIIRS_SNPP_Thermal_Anomalies_375m_All

Furthermore, there is another issue: with layer a. (MODIS), not specifying any time, a default time is used, the wrong one, but still an image is returned. However, layers b. and c. throw the following error in this case:
"msDrawMap(): Image handling error. Failed to draw layer named 'VIIRS_SNPP_Thermal_Anomalies_375m_All'. msShapefileOpen(): Unable to access file. (/archive/geographic/other/shapefiles/firms/FIRMS_SNPP_LL_LNK//YYYY/FIRMS_SNPP_LL_LNKTTTTTTT_) "
For instance I tried with this URL https://gibs.earthdata.nasa.gov/wms/epsg4326/all/wms.cgi?CRS=EPSG:4326&FORMAT=image/png&LAYERS=VIIRS_SNPP_Thermal_Anomalies_375m_All&REQUEST=GetMap&SERVICE=WMS&STYLES=default&VERSION=1.3.0&TRANSPARENT=true&REQUEST=GetMap&WIDTH=1024&HEIGHT=512&BBOX=-90,-180,90,180
Which contradicts GIBS's documentation when no time is specified: https://wiki.earthdata.nasa.gov/display/GIBS/GIBS+API+for+Developers#GIBSAPIforDevelopers-TimeDimension.1

Best regards
Clément

Re: Default time in GIBS WMS requests with time dimension

Posted: Fri Aug 06, 2021 4:39 pm America/New_York
by rboller
Hi Clément,

Thanks for your report - we're aware of this issue and will provide further details next week.

Regards,
Ryan

Re: Default time in GIBS WMS requests with time dimension

Posted: Wed Aug 11, 2021 12:18 pm America/New_York
by adeluca
Hi Clément,

We have found the issue and are going to test a fix this week. We'll let you know when everything is resolved.

Thanks for your patience,
Alex

Re: Default time in GIBS WMS requests with time dimension

Posted: Tue Sep 07, 2021 8:00 am America/New_York
by clementjonglez
Hi Alex,

Thank you for finding the issue, I am looking forward to the fix.

Best regards
Clément

Re: Default time in GIBS WMS requests with time dimension

Posted: Fri Oct 15, 2021 11:05 am America/New_York
by adeluca
Hi Clément,

Sorry for the long delay on this. The fix has finally be pushed out. Let me know questions or issues.

Thanks for your patience,
Alex

Re: Default time in GIBS WMS requests with time dimension

Posted: Tue Oct 19, 2021 4:21 am America/New_York
by clementjonglez
That solved it, thanks a lot!

Cheers
Clément