Measurements of Mouldboard Plow Draft: I. Spectrum Analysis and Filtering

摘要: Measurements of mouldboard plow draft can potentially provide a useful tool for continuously mapping, as surrogate variable, crop limiting soil properties such strength/compaction. Numerous researchers have shown that loading on tillage tools be periodic. One source higher frequency periodic has been related to failure modes in the soil. Lower tools, assuming depth is relatively constant, more often reflects local spatial variability physical moisture, texture, organic matter, and/or This study presents spectrum and cross-spectrum analysis recorded during normal fall plowing operations along adjacent transects. objective this was determine dominant components order elucidate meaningful frequencies which might better variation properties. Spectral densities were generally dominated by signals with few cycles per 300-m transect. The cross-amplitude squared coherency between transects provided further indication characterized because they an correlation function frequency. Spatial dependence data quantified using autocorrelation cross-correlation. An additional use spectral information help design physically filters raw data. Taking Fast Fourier Transform filtering domain optimal filter informed via analysis, convenient method isolating signal.