Programmed data logging in forest harvesting using floating-aperture data compression

A floating-aperture data compression algorithm has been employed in the design of a data acquisition and recording system for monitoring human and machine performance variables in forest harvesting operations. Use of the algorithm allows multiple analog and digital variables to be sampled but not necessarily recorded at 1/1000-min intervals. Data are only recorded when changes on a channel exceed a preset tolerance. Analysis of one of the analog channels recorded in the field illustrates a 52:1 data compression ratio compared with data both sampled and recorded at 1/1000-min intervals. The complete data acquisition and recording system was designed to meet the requirements of field operation and its field use has verified that it functions correctly.