Co-ordinate variables Clause Samples

Co-ordinate variables. All four co-ordinate variables are stored in 2D arrays, with the INSTANCE dimension set to one for single-trajectory storage. The TIME array should be monotonic. The SeaDataNet practice of using Chronological ▇▇▇▇▇▇ ▇▇▇ (CJD) as the numeric representation for time has been followed. The x and y co-ordinates are LONGITUDE and LATITUDE. SeaDataNet convention is to use the 2D WGS- 84 CRS (EPSG 4326). The two co-ordinates share a common qualifier flag variable (POSITION_SEADATANET_QC). The permitted z co-ordinate variables are the same as for profile data, namely DEPTH, HEIGHT or PRES. DEPTH is preferred to PRES.