田块尺度作物长势的实时监测是精准农业的关键。然而，卫星遥感监测范围广但易受天气与空间分辨率制约，无人机（unmanned aerial vehicle, UAV）空间分辨率高但受续航限制，单一数据源难以满足大范围连续监测的需求。针对此问题，本研究基于UAV、Sentinel-2与PlanetScope SuperDove多光谱数据，提出一种基于改进CACAO算法的跨平台时空融合方法。该方法构建了“UAV+Sentinel-2”与“SuperDove+Sentinel-2+UAV”两种数据组合策略，并通过前向预测与后向更新两种模式，近实时地生成每日1米分辨率的归一化植被指数（NDVI）时间序列数据集。进一步采用留一法交叉验证（Leave-One-Out Cross-Validation, LOOCV），并与现有GLM-STF（基于广义线性模型的时空融合，Generalized Linear Model-based Spatiotemporal Fusion）算法进行对比，以评估融合结果的精度。结果表明：（1）不同平台的NDVI数据具有良好的一致性，Sentinel-2与SuperDove NDVI相关性达到0.97，无人机与卫星NDVI相关性超过0.75，满足数据融合的前提；（2）CACAO算法能够有效地重建水稻的物候动态，其中后向更新模式生成的NDVI时间序列更为平滑，且基于CACAO的两种数据组合策略均获得了较高的精度（R > 0.94），在关键物候期引入高时间分辨率的SuperDove数据能在一定程度上提升精度，相关性从0.51提升至0.67；（3）CACAO算法在整个生长季中表现出比GLM-STF算法更稳定和略高的精度优势。综上所述，本研究提出的跨平台融合框架能够有效生成连续、高精度的田块尺度水稻NDVI时间序列，可以为作物长势的精细化监测与精准化管理提供有力的技术支持。

Objective: The real-time and precise monitoring of crop growth status at the field scale is a critical component for achieving modern precision agriculture. Multi-source remote sensing technologies, including satellite platforms and unmanned aerial vehicles (UAVs), have emerged as effective non-destructive tools for this purpose. However, these data sources present a significant spatiotemporal trade-off, limiting their independent utility. Satellite remote sensing, while offering broad-area coverage, is often constrained by adverse weather conditions and insufficient spatial resolution to capture in-field variability. Conversely, UAV remote sensing provides exceptionally high spatial resolution but is hampered by limited battery endurance, making large-scale continuous (e.g., daily) monitoring challenging. Consequently, a single data source is inadequate for supporting the continuous monitoring of crop growth at the field scale. To address this critical gap, this study proposes a cross-platform spatiotemporal fusion method. The objective is to synergistically integrate satellite and UAV data, effectively leveraging their complementary temporal and spatial resolutions to generate a continuous, high-resolution dataset for precision agriculture. Method: This research was based on a synergistic combination of multi-platform, multispectral remote sensing data, including high-resolution UAV imagery, Sentinel-2 data and PlanetScope SuperDove data. We developed an improved CACAO (Consistent Adjustment of the Climatology to Actual Observations) algorithm, adapting its core logic for cross-platform data fusion rather than its original climatological application. Two distinct data combination strategies were designed and tested: (1) a baseline “UAV+Sentinel-2” strategy and (2) an enhanced “SuperDove+Sentinel-2+UAV” strategy, which integrates high-frequency commercial satellite data. The CACAO framework was implemented using two distinct modes: a “forward prediction” (FP) mode, designed for near real-time applications, and a “backward updating” (BU) mode, which iteratively refines historical estimates as new data becomes available. The final output of the framework is a near real-time, daily 1-meter resolution normalized difference vegetation index (NDVI) time-series dataset. The accuracy of the fusion results was rigorously evaluated using two methods: (1) Leave-One-Out Cross-Validation (LOOCV), which assesses the model’s predictive power, and (2) a benchmark comparison against the established GLM-STF (Generalized Linear Model-based Spatiotemporal Fusion) algorithm. Result: The prerequisite for data fusion was confirmed as NDVI data from the different platforms exhibited good consistency, with a strong correlation between Sentinel-2 and SuperDove (R = 0.97) and a reliable correlation was observed between UAV and satellite data (R > 0.75). In addition, the CACAO algorithm was proven to effectively reconstruct the phenological dynamics of the rice crop. A key finding was that the backward updating (BU) mode produced a significantly smoother and more robust NDVI time series than the forward prediction (FP) mode. Both CACAO-based data combination strategies achieved high overall accuracy (R > 0.94). Critically, the study demonstrated that introducing high-temporal-resolution SuperDove data during key phenological stages can substantially improve accuracy, with the correlation increasing from 0.51 to 0.67 in a specific validation case. Finally, in the comparative analysis, the CACAO algorithm demonstrated greater stability and slightly higher accuracy than the GLM-STF algorithm, particularly showing more robust performance across the entire growing season. Conclusion: In conclusion, the cross-platform fusion framework proposed in this study, centered on the improved CACAO algorithm, is an effective and robust solution for generating continuous, high-precision (daily 1-meter) field-scale rice NDVI time series. This approach successfully overcomes the limitations of single-source data platforms. The framework provides strong technical support for the fine-grained monitoring of crop growth and the implementation of precision management strategies in modern agriculture.