Default time in GIBS WMS requests with time dimension
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- Posts: 3
- Joined: Thu Jul 29, 2021 10:52 am America/New_York
Default time in GIBS WMS requests with time dimension
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
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
- Attachments
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- MODIS, no date specified
- modis-no-date-specified.png (49.18 KiB) Not viewed yet
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- MODIS, date specified 2021-07-27
- modis-2021-07-27.png (53.75 KiB) Not viewed yet
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Re: Default time in GIBS WMS requests with time dimension
Hi Clément,
Thanks for your report - we're aware of this issue and will provide further details next week.
Regards,
Ryan
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
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
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
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- Posts: 3
- Joined: Thu Jul 29, 2021 10:52 am America/New_York
Re: Default time in GIBS WMS requests with time dimension
Hi Alex,
Thank you for finding the issue, I am looking forward to the fix.
Best regards
Clément
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
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
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
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- Posts: 3
- Joined: Thu Jul 29, 2021 10:52 am America/New_York
Re: Default time in GIBS WMS requests with time dimension
That solved it, thanks a lot!
Cheers
Clément
Cheers
Clément