I've added this feature request to our list. Jon Blower might have some
thoughts on this as well.
One thing that I wonder about is client support. In particular, does
Godiva2 support this? Again, a question for Jon.
On 12/22/2010 6:00 AM, Rich Signell wrote:
> For getCapabilities requests, it would be great if the TDS would
> express the available times using the WMS multiple time interval
> syntax if it is more efficient than listing each time value
> This can result in huge (100 or more) savings in the WMS
> getCapabilities size when dealing with model output, which is usually
> equally spaced, but perhaps with a few gaps. Instead of listing
> every available time step in ISO format, as is done currently
> In WMS 1.1.1, Annex C.3 states that multiple intervals are allowed in
> the "Extent" element.
> In WMS 1.3.0, Annex C.2 states that multiple intervals are allowed in
> the "Dimension" element.
> Both list the sample format: "min1/max1/res1,min2/max2/res2,..."
> (thanks to Kyle Wilcox for digging out this info)
> For example, we have a dataset
> that contains hourly output over 21 years (183984 time records) for 11
> different variables. There are only 4 gaps longer than 1 hour.
> If you access the WMS getCapabilities document for this dataset, be
> prepared to wait for a while, because it's 51Mb!!
> The problem is that each time value is listed in ISO ASCII:
> <Dimension name="time" units="ISO8601" multipleValues="true"
> current="true" default="2006-01-01T00:00:00.000Z">
> which goes on for 5MB of ASCII values and then this whole mess is
> repeated for each variable "layer".
> Instead, the entire time record could be simply expressed using 5
> intervals of the form:
> Existing way (every time step written out): 51MB
> New way (specifying intervals): 100Kb (500 times
> This would greatly reduce the file sizes on Motherlode, our IOOS
> testbed server, and every other TDS (or WMS, actually) with aggregated
> model output.