Abstract: A system and method to modularize a signal observation process to allow continual adaptation as the independent modules evolve. Receivers, digitizers, storage, and synchronization means form discrete subsystems that can be integrated together yet still be independently upgraded or modified. The integrated system is controlled by software that allows continuous deterministic signal observation for arbitrarily long periods of time. The software enables a schedule-based temporal collection of signals through a method that controls the tuning of the receivers and the downloading of data to storage media. The control software also allows automatic distributed operation of multiple sites in synchronization to within parts per million or better.