O inSSIDer pode ser o que você está procurando. Do site:
YOU CAN
– Inspect your Wi-Fi and surrounding networks
– Scan and filter hundreds of nearby access points
– Troubleshoot competing access points and clogged Wi-Fi channels
– Highlight access points for areas with high Wi-Fi concentration
– Track the strength of received signals in dBm over time
– Sort results by MAC Address, SSID, Channel, RSSI, Time Last Seen
– Export Wi-Fi and GPS data to a KML file in Google Earth
FEATURES
– Uses your current wireless card and connection software
– Works with Windows XP, Vista, and 7 (32 and 64 bit)
– Compatible with most GPS devices (NMEA v2.3 +)
E é grátis. Eu usei cargas no passado e é uma grande ferramenta pequena (não, eu não trabalho para eles). Obtenha aqui