New Methods for Automatic Delay Time Compensation in Grain Yield Maps

Crop yield data is a key component of precision agriculture, critical for both development and evaluation of precision management strategies. Ideally, software that generates grain yield maps from raw yield monitor data should automatically correct common errors associated with machine and operating characteristics. Perhaps the most basic correction required is to properly compensate for the time lag (or position lag) between the cutting of the crop from the field and the grain flow measurement by the flow sensor in the combine. Past research has suggested several approaches to automatically determine delay time but for various reasons these have not been implemented in mapping software. In this paper we present a new, computationally efficient method that can accurately determine delay time for individual fields using the image processing method of phase correlation. This method was evaluated using a number of yield maps with varying degrees of harvest complexity and results were compared to a geostatistical method. The new method performed satisfactorily on larger datasets with a significant amount of spatial variability. Additionally, this method was more computationally efficient than previous methods. Results of this study will increase the feasibility of including automatic delay time compensation in yield mapping software.