root# iwlist wlan0 scan
Where wlan0 is wireless interface
Security experts and hackers use Aircrack ng suite for details scanning of wireless networks.
We can use following commands for monitoring wireless networks and collect IVS that can be used to cracking WEP keys used for security of wireless networks
root# airmon-ng start wlan0
root# airodump-ng -w output -c 1wlan0
(here wireless AP is listening on channel1 and IV collected in output.* files)
Check check output of these commands you will get better idea.