The Effect of Workload on Performance of Operators Monitoring Unattended Ground Sensors
Abstract
The objective was to determine the effect of workload (target activity level and number of sensors used) on unattended ground sensor (UGS) operators' target-detection ability, false-alarm rate, and direction and speed estimation accuracy. Experienced operators monitored activations of UGS used in grids under six workload conditions--two levels of target activity x three levels of number of sensors monitored. Target activity level was defined as either 5 or 14 vehicle groups per 27 sensors per hour. The operators monitored in counterbalanced sequence 27 sensors (3 grids), 54 sensors (6 grids), and 108 sensors (12 grids). Percentage of detections decreased linearly from 85% (4 to 6 vehicle groups per hour presented on 27 sensors) to 26% (about 40 vehicle groups per hour presented on 108 sensors). Without special training, operators should monitor no more than 60 sensors being activated by a maximum of 10 vehicular groups per hour (detection completeness for this condition was 76%). The number of false alarms and the accuracy of speed estimation did not significantly change over workload. Operator accuracy in direction estimation decreased significantly as a function of workload from true azimuth + or - 30 deg. to true azimuth + or - 54 deg.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1978
- Accession Number
- ADA061694
Entities
People
- Billy E. Biggs
- Harold Martinek
- Lawrence R. Edwards
- Sterling S. Pilette
Organizations
- HRB Systems