Radio frequency spectrum monitoring

In recent years, I developed a multifunction client-server application suite designed to facilitate interactive and scheduled monitoring of the airwaves:

Schematic

This application suite supports a variety of instruments, including several spectrum analyzers and test receivers, signal generators, antenna rotators, and more. Instruments are controlled through GPIB/HPIB, RS-232, or proprietary interfaces like ICOM's CI-V. Additionally, recording and transmission of digital audio is supported.

Device Selection

Instruments are controlled by a remote server co-located with them. Client computers communicate with the remote server using TCP/IP. The suite is designed to function on low-bandwidth connections; simple instrument control is possible even over a cellular modem connection. A regular dial-up connection is sufficient to control a receiver and obtain digital audio in real time. An adaptive transmission algorithm ensures that the suite remains responsive even over unreliable connections.

The instrument interfaces ("virtual instruments") are designed to replicate all important instrument functionality to the remote user. Of particular interest are real-time graphical trances obtained from the instrument and transmitted for visual presentation on the client machine.

ESN

In addition to interactive instrument control, the suite also contains components that support background operation. It is possible to schedule high-speed scans, audio recordings, and other background activity.

Scheduler

In addition to the core components, the suite contains several helper applications, including configuration and instrument calibration programs. All components offer a bilingual English-French user interface.