Mike, These variables don’t qualify as a trajectory. Based on your CDL you provided, it appears that you have 5 different time series that are on different periods / frequencies. I’m wondering if there is a problem with how you are trying to organize this data, since what you have described tells me that you don’t collect longitudes at the same rate as latitudes, and collect altitudes much faster than either lon or lat. The same holds for your O3 and NO3 measurements. It also says that none of the rates are multiples of any of the others. That may be true, but it seems quite odd. So, before anything else, is your data really this complex, time-wise?
Grace and peace, Jim Visit us on Facebook Jim Biard Research Scholar Cooperative Institute for Climate and Satellites NC North Carolina State University NOAA's National Climatic Data Center 151 Patton Ave, Asheville, NC 28801 e: [email protected] o: +1 828 271 4900 On Mar 18, 2014, at 3:10 PM, Mike Godin <[email protected]> wrote: > I am considering a file from a sampling system that follows a trajectory, but > which collects each variable independently of each other. It would have with > a header that looks like the following (adapted from "Example H.13. A single > trajectory recording atmospheric composition."): > > dimensions: > time_lon = 42; > time_lat = 55; > time_z = 435; > time_O3 = 335; > time_NO3 = 5357; > > variables: > double time_lon(time_lon) ; > time_lon:standard_name = "time"; > time_lon:long_name = "time_lon" ; > time_lon:units = "days since 1970-01-01 00:00:00" ; > float lon(time_lon) ; > lon:standard_name = "longitude"; > lon:long_name = "longitude" ; > lon:units = "degrees_east" ; > double time_lat(time_lat) ; > time_lat:standard_name = "time"; > time_lat:long_name = "time_lat" ; > time_lat:units = "days since 1970-01-01 00:00:00" ; > float lat(time_lat) ; > lat:standard_name = "latitude"; > lat:long_name = "latitude" ; > lat:units = "degrees_north" ; > double time_z(time_z) ; > time_z:standard_name = "time"; > time_z:long_name = "time_z" ; > time_z:units = "days since 1970-01-01 00:00:00" ; > float z(time_z) ; > z:standard_name = “altitude”; > z:long_name = "height above mean sea level" ; > z:units = "km" ; > z:positive = "up" ; > z:axis = "Z" ; > > double time_O3(time_O3) ; > time_O3:standard_name = "time"; > time_O3:long_name = "time_O3" ; > time_O3:units = "days since 1970-01-01 00:00:00" ; > float O3(time_O3) ; > O3:standard_name = “mass_fraction_of_ozone_in_air”; > O3:long_name = "ozone concentration" ; > O3:units = "1e-9" ; > O3:coordinates = "time_O3 lon lat z" ; > > double time_NO3(time_NO3) ; > time_NO3:standard_name = "time"; > time_NO3:long_name = "time_NO3" ; > time_NO3:units = "days since 1970-01-01 00:00:00" ; > float O3(time_NO3) ; > NO3:standard_name = “mass_fraction_of_nitrate_radical_in_air”; > NO3:long_name = "NO3 concentration" ; > NO3:units = "1e-9" ; > NO3:coordinates = "time_NO3 lon lat z" ; > > attributes: > :featureType = "????"; > > The data points could be sampled to generate a header exactly like the > example from the standard, but in doing so, one would lose information about > the timing of each variable's values, and would either end up with data loss, > or a much larger file. So I'm wondering: is this a valid "H.4.2. Single > trajectory"? If not, is it something that can be annotated as a valid CF > metadata file without altering the measured data? > > Thanks, Mike Godin > _______________________________________________ > CF-metadata mailing list > [email protected] > http://mailman.cgd.ucar.edu/mailman/listinfo/cf-metadata
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