Global food security is under increasing strain, with timely and accurate crop distribution data becoming crucial for effective policy-making. Traditional agricultural surveys are often slow and labor-intensive, while remote sensing, though highly effective in covering large areas with high spatiotemporal resolution, typically produces crop maps late in the growing season. Early crop identification is further complicated by limited observational data and subtle spectral characteristics. Addressing these challenges, the need for more efficient early crop identification technologies has become critical.
On 19 March 2025, a team of researchers from the School of Geography and Planning at Sun Yat-sen University published a study (DOI: 10.34133/remotesensing.0438) in Journal of Remote Sensing, proposing a novel method for early crop identification using Bayesian Probability Update Model (BPUM). This technique merges historical crop data with real-time remote sensing, overcoming data gaps and improving classification accuracy during the early crop growth stages. The study aims to offer more timely insights into crop distribution, assisting agricultural production and food security strategies.
The study’s central innovation is the development of BPUM, which iteratively updates crop planting probabilities by integrating historical knowledge and real-time data. This approach allows for accurate crop identification 1-2 months ahead of traditional methods. By optimizing classification stability and applicability, BPUM proves effective across regions with diverse climatic conditions, making it a versatile tool for global agricultural monitoring.
The team tested BPUM in two U.S. agricultural regions with differing climates—Minnesota and Georgia. BPUM's early-stage accuracy outperforms conventional techniques, achieving overall classification accuracies of 94.66% and 96.00% in two study areas. By extracting spatiotemporal features from historical crop maps (CDL), the researchers trained an Artificial Neural Network (ANN) model to predict prior crop probabilities. The Bayesian formula was then applied to combine this prior knowledge with remote sensing data, iteratively refining the crop planting predictions. The results demonstrated BPUM’s superior accuracy during early growth stages (April to May), especially when crop spectral characteristics were not yet distinct. The integration of historical data significantly enhanced classification precision.
“The strength of BPUM lies in its ability to continuously improve crop classification through iterative updates, combining historical insights with real-time data,” said the research team. “This model not only advances early crop identification but also opens new avenues for agricultural monitoring and food security decision-making.”
The research team conducted multiple experiments to validate BPUM’s performance under various data combinations and time frames. The team also highlighted the classification ability of BPUM by demonstrating the pixel correction process in classification and comparing it with other early mapping methods, and emphasized the advantages of organically integrating prior knowledge and remote sensing data.
Looking ahead, BPUM holds immense promise for widespread application, particularly in regions lacking historical crop maps. By incorporating lower-resolution remote sensing data, BPUM could play a key role in large-scale crop mapping efforts. Its potential extends beyond early crop identification, contributing to global food security, agricultural management, and climate change response, while promoting the sustainable development of agriculture worldwide.
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References
DOI
10.34133/remotesensing.0438
Original Source URL
https://spj.science.org/doi/10.34133/remotesensing.0438
Funding information
This study was supported in part by the National Key R&D Program of China under Grant 2022YFB3903402, in part by the National Natural Science Foundation of China under Grant 42222106, and in part by the National Natural Science Foundation of China under Grant 61976234.
About Journal of Remote Sensing
The Journal of Remote Sensing, an online-only Open Access journal published in association with AIR-CAS, promotes the theory, science, and technology of remote sensing, as well as interdisciplinary research within earth and information science.