The goal is to test the usefulness of a portable system, capable of recording the frequency spectrum with time stamp and GPS information.
The setup consisted on:
- A laptop running the "SMA Simple Spectrum Analyser" software
- The SMA "138MHz-4.4GHz 35M-4.4G USB SMA Source/Signal Generator/Simple Spectrum Analyzer" device
- A Blutooth GPS receiver
- A suitable antenna
- The setup allows to display signal power of a single frequency in a comprehensive maps view.
- The resulting mapped data can be used to determine reception quality within an area.
- It can be used to locate a transmitter.
- It can be used to determine the effect of local obstacles like buildings, trees or mountains.
- The setup is fairly easy and cost effective.
- In order to create usable spectrum recordings, a propper omnidirectional antenna has to be used. This may constitute a problem, but since the car in movement does not always point to the same direction, there is no alternative other than possibly a real-time self orienting antenna.
- The Bluetooth GPS receiver can be difficult to pair and sync to the laptop. A GPS receiver with RS-232 interface is more reliable.
- The whole setup involves several devices and cables. Hence it is very distracting for the driver and prone to errors due to moving parts. It is recommended to build a suitable fixture for all components and have the laptop set out of view in regards to the driver.