Factors Contributing to Sensor Density

This white paper is written for system designers developing or optimizing an in-place monitoring system (IPMS) supporting technical surveillance countermeasures (TSCM), cybersecurity, electronic device policy enforcement, spectrum management, and similar critical missions. By providing insight to questions such as “How many sensors do I need?” and “How far apart can they be spaced?”, this white paper assists designers with understanding how key factors, such as receiver noise figure (NF), directly influence the density and distribution of sensors within the total system deployment.

Frequency range, instantaneous bandwidth, and sweep speed are typically understood with respect to their value to an IPMS designed for detection and analysis of anomalous signals. By understanding the approach and techniques presented in this white paper, designers should be capable of evaluating receiver performance against particular threat characteristics that are all too often overlooked, such as signal strength, possible transmitter and receiver locations, and directionality.

This white paper demonstrates that, for an effective IPMS, sensor density is primarily dictated by the specifications and performance of its sensors — most especially the sensor’s noise figure. In specifying and designing an IPMS, selection of the most cost-effective and mission-effective sensor requires a judicious examination of sensor performance and mission objectives — a low-cost sensor with poor noise figure may likely result in a high-cost IPMS with performance limitations, versus fewer high-performance sensors with excellent noise figures.