Journal Paper Digests 2026 #23
- Applications of electronic nose and electronic tongue technologies in agricultural and food inspection: A review
- Beyond SMAP: Can GNSS-R Platforms Ensure Continuity of Global Soil Moisture Observations?
Beyond SMAP: Can GNSS-R Platforms Ensure Continuity of Global Soil Moisture Observations?
The absence of a definitive follow-on strategy for the Soil Moisture Active Passive (SMAP) mission, which has already surpassed its planned mission lifetime, presents a significant challenge for the hydrological science community. GNSS-Reflectometry (GNSS-R), which exploits reflected satellite navigation signals, has emerged as a rapidly growing alternative for soil moisture retrieval, increasingly positioned as a low-cost path to global observation. The two approaches, however, differ fundamentally in how they sense the surface, and the hydrological science community should weigh these differences carefully before decisions are made that could compromise the continuity of this essential climate variable’s data record. In this study, we compared soil moisture products from these two systems across seven perspectives: (a) observation characteristics, (b) spatial resolution, (c) coverage and frequency of observations, (d) vulnerability to radio frequency interference, (e) complementarity potential, (f) performance, and (g) cost considerations. Our assessment suggests that GNSS-R is better understood as a complement to SMAP than as a replacement. A GNSS-R constellation can deliver sub-daily observations, and lower upfront costs, capabilities that genuinely extend what single-platform missions can offer. At the same time, GNSS-R retrievals exhibit variable spatial sampling and canopy attenuation, and the highest-performing products are typically trained, calibrated, or benchmarked against SMAP (an implicit cost that the low-cost framing of GNSS-R does not fully capture). Taken together, these findings underscore the need for sustained investment in both SMAP-class L-band missions and the expanding GNSS-R constellation, each contributing complementarity strengths to a resilient global soil moisture observing system.
Applications of electronic nose and electronic tongue technologies in agricultural and food inspection: A review
Electronic-nose and electronic-tongue technologies provide rapid approaches for characterising volatile and non-volatile fingerprints in agricultural products and foods. Electronic noses can support non-destructive headspace measurements, whereas electronic tongues generally require liquid-phase sampling or extraction. This review examines their sensing principles, chemometric workflows, and applications in quality grading, authenticity verification, adulteration detection, and safety monitoring. Particular attention is given to the transition from exploratory classification towards validated quantitative prediction and to the use of data-, feature-, and decision-level fusion. Cross-modal combinations with machine vision, spectroscopy, chromatography, and tactile sensing are also evaluated according to whether they constitute genuine data fusion, complementary characterisation, or analytical validation. The reviewed studies demonstrate substantial analytical potential, but most fusion models have been evaluated under controlled laboratory conditions. Evidence from long-term, multi-batch, cross-device, and production-line deployment remains limited. Future industrial translation will therefore require improved sensor stability, standardised sampling, external validation, model-transfer strategies, interpretable algorithms, and engineering designs suitable for routine operation.