Multiple Identical sensors

[SBS-EREHM]

I think there is a problem with SENSOR and PARAMETER_SENSOR when there is more than one instance of a specific SENSOR on a float.

If I have a float with two CTDs, I could, for example, repeat CTD_PRES, CTD_TEMP, and CTD_CNDC in the SENSOR array. Similarly, if i have two oxygen optodes, I can repeat OPTODE_DOXY. (Ignore blank padding for the moment.):

SENSOR =
"CTD_PRES ", // CTD1
"CTD_TEMP ",
"CTD_CNDC ",
"CTD_PRES ", // CTD2
"CTD_TEMP ",
"CTD_CNDC ",
"OPTODE_DOXY " , // Optode1
"OPTODE_DOXY " ; // Optode2

Problem: SENSOR entries are controlled by R25. In the PARAMETER section, there is a least one PARAMETER (R03) measured per SENSOR. The PARAMETER_SENSOR links a PARAMETER to a SENSOR using R25. In this case, it would be ambiguous. For this example, there would necessarily be a PARAMETER entry for each temperature (TEMP) for which the PARAMETER_SENSOR for both would be CTD_TEMP. But to which CTD are we referring?

PARAMETER = "PRES", "PRES", "TEMP", "TEMP", "CNDC", "CNDC", "DOXY", "DOXY", ...
PARAMETER_SENSOR = "CTD_PRES", "CTD_PRES", "CTD_TEMP", "CTD_TEMP", "CTD_CNDC", "CTD_CNDC", "OPTODE_DOXY", "OPTODE_DOXY", ....

ArgoDM community can simply dismiss these floats as non-standard, and ask that second instance of an identical sensor be put in the auxiliary file (metadata + data). That does not solve the example of a Triple-O2-optode float, though.

One sufficient solution would be to augment R25 with entries with an optional suffix indicating instance number, e.g, CTD_TEMP, CTD_TEMP2, etc. This would lead to a doubling, tripling, etc. of the number of controlled SENSOR values in R25.

SENSOR = "CTD_PRES", "CTD_TEMP", "CTD_CNDC", "CTD_PRES2 ", "CTD_TEMP2 ", "CTD_CNDC2", "OPTODE_DOXY", "OPTODE_DOXY2 " ;
PARAMETER = "PRES", "PRES", "TEMP", "TEMP", "CNDC", "CNDC", "DOXY", "DOXY", ...
PARAMETER_SENSOR = "CTD_PRES", "CTD_PRES2", "CTD_TEMP", "CTD_TEMP2", "CTD_CNDC", "CTD_CNDC2",
"OPTODE_DOXY", "OPTODE_DOXY2", ....

Another possible solution would involve adding an additional metadata element to each of the SENSOR (2.4.7.1) and PARAMETER (2.4.7.2) lists in the Argo User Manual specifying an ordinal identifying the SENSOR instance, e.g., SENSOR_INSTANCE and PARAMETER_SENSOR_INSTANCE, respectively.

[HCBScienceProducts]

I'd think this is dealt with by §3.3.1 Parameters from duplicate sensors of the User Manual, isn't it?

There are a couple of examples for duplicate sensors in the data system, see, e.g., Brian's unique-dump of the SENSOR field just shown at ADMT24 (slide 9 with both OPTODE_DOXY and OPTODE_DOXY2).

-> Mark as solved?

[vpaba]

Also related with #81

Please reopen if needed