Hi David -
I moved to email to avoid cluttering up the ticket.
My CDL files are so ridiculously long that I'll just include the relevant
snippets - please let me know if you'd rather see the actual CDL.
In this file, 'inst' is a dimensionless variable that points (by way of the
ancillary variables attribute) to the variables that contain the
information
about the instruments. I'm putting this metadata into variables instead
of attributes because I need the depth dimension; I think this is becoming
more widely used as a way to document in situ data.
Formerly, I'd have tied 'inst' to the data variable (temp) as an ancillary
variable, but the new NODC templates have introduced the 'instrument'
attribute, so I'm using that instead.
I don't consider any of the instrument variables to be auxiliary
coordinates
in any sense - they're ancillary variables containing metadata.
Thanks -
Nan
netcdf OS_Stratus_2001_D_T300Sec {
dimensions:
time = 105883 ;
depth = 12 ;
latitude = 1 ;
longitude = 1 ;
strlen1 = 20 ;
strlen2 = 6 ;
strlen3 = 90 ;
variables:
double time(time) ;
time:standard_name = "time" ;
double depth(depth) ;
depth:standard_name = "depth" ;
double latitude(latitude) ;
latitude:standard_name = "latitude" ;
double longitude(longitude) ;
longitude:standard_name = "longitude" ;
double temp(time, depth) ;
temp:standard_name = "sea_water_temperature" ;
temp:coordinates = "time depth latitude longitude" ;
temp:instrument= "inst" ;
int inst ;
inst:long_name = "instruments" ;
inst:ancillary_variables = "inst_mfgr inst_mod inst_sn inst_url" ;
char inst_mfgr(depth, strlen1) ;
inst_mfgr:long_name = "instrument manufacturer" ;
char inst_model(depth, strlen2) ;
inst_model:long_name = "instrument model name" ;
int inst_sn(depth) ;
inst_sn:long_name = "instrument serial number" ;
inst_sn:units = "1" ;
char inst_url(depth, strlen3) ;
inst_url:long_name = "instrument reference url" ;
On 6/20/12 6:17 AM, David Hassell wrote:
> #68: CF data model and reference implementation in Python
> -----------------------------+----------------------------------------------
> Reporter: jonathan | Owner: cf-conventions at lists.llnl.gov
> Type: enhancement | Status: new
> Priority: medium | Milestone:
> Component: cf-conventions | Version:
> Resolution: | Keywords:
> -----------------------------+----------------------------------------------
> Comment (by davidhassell):
>
> Replying to [comment:13 ngalbraith]:
>
> Hello Nan,
>
> Thanks for the question. I don't believe that it was our intention to
> limit the use of variables without data arrays.
>
> It would, however, be very useful to see the CDL of your example, as I
> fear that I don't yet undertstand it - is the instrument variable 'data'
> or 'metadata'? Are the ancillary variables (of serial numbers,
> manufacturer, etc.) in some sense auxiliary coordinates? (not independent
> questions!). I'm sure the full CDL of would clear it up for me.
>
> All the best,
>
> David
>
--
*******************************************************
* Nan Galbraith (508) 289-2444 *
* Upper Ocean Processes Group Mail Stop 29 *
* Woods Hole Oceanographic Institution *
* Woods Hole, MA 02543 *
*******************************************************
Received on Wed Jun 20 2012 - 14:01:11 BST
