• Diversification of sensing modalities and transduction principles across late-1960s studies, illustrating a broad methodological expansion from solid-state mosaics to electrochemical, optical, magnetic, and piezoelectric sensors [1], [2], [10], [16], [20], [13], [9].

• Thermal/heat-transfer based sensing methods for environmental and fluid measurements, emphasizing line-source and point-source heating in soils and hot-film gauges [6], [9], [19], [8], [2].

• Calibration, correction, and accuracy improvement across sensors, including perturbation theory, dynamic sensitivity, cosine-law corrections, and numerical filtering for indirect sensing [7], [8], [5], [17], [11], [13].

• Field-oriented environmental sensing and long-term instrumentation for soil, aquatic, and atmospheric contexts, highlighting portable field instruments and in situ measurements [14], [20], [15], [9].