Scanmeter
WiFi Antenna
Tuning Software for Linux
Although
there
are many great WiFi related programs available in Linux there isn't a
good antenna setup software like the Netstumbler
in Windows. Of
course, Linux has the all powerful Kismet
and the simple to use
Wavemon but neither is very useful
when it comes to measuring 802.11 RF
signal level and plotting a histogram. I build and test high gain
WiFi antennas as a hobby and need a simple measuring tool so I wrote
Scanmeter which is a bash script that measures signal strength and
displays the wireless strength in a histogram [Fig. 1].
High
gain
antennas are directional by design. When pointing a directional
antenna it is important to measure the WiFi signal level as we move
the antenna. Even when you know the general direction of the access
point, small azimuth angle, elevation and polarization corrections
can produce big differences in signal amplitude.
This is
especially true for distant WiFi access points. Imagine shining a
laser pointer at a building several blocks away. A small movement
of hand will move the laser dot in large sweeps. WiFi antennas are
not as focused as a laser beam but when going for distance every dB
counts so it is important to aim right.
Scanmeter
features a continuously updating histogram. While you are
adjusting the position of your high gain WiFi antenna the signal is
plotted on screen live so you can find the “sweet spot” without
guessing. 1,
2
1,
2
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