Integrating High-Resolution Imaging and Water-Sensitive Paper for Enhanced Agricultural Spray Droplet Characterization

Water-sensitive papers (WSP) have emerged as a low-cost, field-deployable spray characterization method, posing significant challenges for field deployment. To address the limitations of existing WSP analysis approaches, this work presents a comprehensive methodology for the characterization of agricultural spray droplets using WSP and image processing techniques. This methodology is validated through testing that encompasses a range of scenarios, including varying droplet densities, simulating overlap, and utilizing different resolution cameras for image capture. The results indicate that camera resolution consistently plays a critical role in minimizing measurement errors across different droplet stain types, particularly for single and double stains. Higher resolution cameras (2560x1440) significantly improve the accuracy of coverage and diameter measurements, reducing both MAE and RMSE and yielding higher R2 values, suggesting a better fit. This analysis provides valuable insights for optimizing the setup in environmental and agricultural assessments involving WSP.