Biometric security in cranes at ground (6,4)

I believe the answer is:

retina scan

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'biometric security' is the definition.
I don't know anything about this answer so I cannot judge whether it can be defined by this definition.

'in cranes at ground' is the wordplay.
'ground' indicates an anagram ('grind' the letters into a new form).
'in'+'cranes'+'at'='incranesat'
'incranesat' anagrammed gives 'RETINA SCAN'.

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I've seen this clue in the Sydney Morning Herald.

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