The dynamic accuracy of a tracking total station (TTS) was evaluated using a rotary test fixture to determine the viability of using a TTS as a position reference for dynamic global navigation satellite-based system (GNSS) accuracy testing. Tests were performed at angular velocities ranging from 0 to 3.72 rad/s at a radius of 0.635 m. A technique was developed to determine the average latency of the TTS measurement serial data output. TTS measurements were interpolated at a GNSS sampling interval to provide a method for direct comparison between TTS and GNSS position measurements. The estimated latency from the TTS serial data output was shown to be consistently near 0.25 s for all angular velocities and less variable when using a reflector-based machine target versus a prism-based target. Average positional error in the TTS position measurement increased with angular velocity from 3 to 90 mm, partly due to internal filtering which caused the magnitude of the TTS position measurement to decrease under stead-state sinusoidal motion. The standard deviation of error ranged from less than 1 to 20 mm as angular velocity increased. Sight distance from the TTS to the target was shown to have very little effect on accuracy between 4 and 30 m. The TTS was determined to be an adequate benchmark for most dynamic GNSS and vehicle auto-guidance testing but is limited by relatively large position measurement errors at high angular velocities.
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This material is based upon work supported by the USDA National Institute of Food and Agriculture under agreements 2008-34628-19532 and 2010-34628-21691. Any opinions, findings, or conclusions expressed in this publication are those of the author(s) and do not necessarily reflect the view of the USDA.
Sama, Michael P. and Stombaugh, Timothy S., "Performance Evaluation of a Tracking Total Station as a Position Reference forDynamic GNSS Accuracy Testing" (2014). Biosystems and Agricultural Engineering Faculty Publications. 8.