SensorArrays

A sensor array is a collection of spatially distributed sensing elements designed to measure a physical quantity or field. By combining data from multiple elements, sensor arrays can improve spatial resolution, sensitivity, robustness, and coverage beyond what a single sensor can achieve. Arrays are used across electromagnetic, acoustic, optical, chemical, and thermal domains.

Arrays are characterized by geometry (linear, planar, cylindrical, or spherical), inter-element spacing, and the sensing modality. The elements may be identical or heterogeneous; synchronization and calibration are critical to maintain coherence. Data from the array are processed with algorithms such as beamforming, direction-of-arrival estimation, tomographic reconstruction, and data fusion. For wave-based sensing, spacing is chosen to control aliasing (typically less than half the wavelength). The underlying principle is spatial sampling and constructive/destructive interference to extract information about the field.

Examples include microphone arrays for sound localization and noise reduction; antenna arrays for wireless communications, radar, and radio astronomy; seismic arrays for imaging subsurface structure; ultrasound arrays for medical imaging; optical or infrared sensor arrays in imaging systems; chemical sensor arrays (electronic noses) for pattern recognition.

Design considerations include calibration, mutual coupling between elements, crosstalk, environmental variability, synchronization, processing latency, and data volume. Trade-offs exist among resolution, field of view, bandwidth, and cost. Advances include distributed and sparse arrays, compressive sensing, coded aperture techniques, and adaptive beamforming.

History and impact: sensor arrays have roots in acoustics and radio engineering, with major advances driving radar, sonar, and communications. Today they underpin many technologies in defense, industry, and research.