<?xml version="1.0" encoding="UTF-8"?>
<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2" location="C:/Users/yuanho/Downloads/smallerpd.nc">
<variable name="trajectory_id">
<attribute name="standard_name" value="trajectory_id"/>
</variable>
<variable name="depth" shape="trajectory obs" type="float">
<attribute name="axis" value="Z"/>
</variable>
<attribute name="CF\:featureType" value="trajectory"/>
</netcdf>
1) you do need 2D time time(traj,obs)
2) attribute is CF:featureType, not CF\:featureType, the \: is only for CDL
this seems to work:
<attribute name="CF:featureType" value="trajectory"/> </netcdf>
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