Hi,
As said before - only instant AP can't work without a Aruba controller (iAP105 not AP105)
other method... config your AP as RAP in front of a controller | and build an SSID that will stay "on air" (BACKUP/persist - ALWAYS ON) and then u will be able to keep your AP signal up and do a site survey.
*But remmamber - Thr ap unit(even as RAP) will still need a connectivity to a controller (even not in the same lan) in first boot of the ap...and it will not work without a eth connected to a lan port (the watchdog will reboot the apunit)
*consider to buy instant version of iAP105 (also need cable connected or it will search for mesh connectivity to another virtual controller on the same segment) or RAP-3WN with 3g stick*
Regards.
Me.