Analysis of Station Quality Issues from EarthScope's Transportable Array

160 of the first 400 Earthscope USARRY transportable array (TA) stations have completed their first two-year deployment and are being moved to their next locations. Over the past 4 years the majority of stations have run with few interruptions in the transfer of real time data to the Array Network Facility (ANF) at the Univ of CA San Diego and near real time data to the IRIS Data Management System (DMS). The combination of telemetered data and dedicated people reviewing the waveforms and state of health data have revealed several conditions that can affect the data quality or cause loss of data. The data problems fall into three broad categories; station power, equipment malfunction, and communication failures. Station power issues have been implicated in several types of noise seen in the seismic data (as well as causing station failures and resultant data gaps). The most common type of equipment problem that has been found to degrade data quality is caused by sensor problems, and has affected all 3 types of sensors used in the TA to varying degrees. While communication problems can cause real time data loss, they do not cause a degradation of the quality of the data, and any gaps in the real time data due solely to communications problems are filled in later with the continuous data recorded to disk at each TA station. Over the past 4 years the TA team has recognized a number of noise sources and have made several design changes to minimize the effects on data quality. Design/procedural changes include: stopping water incursion into the stations, power conditioning, changing mass re-center voltage thresholds. Figures that demonstrate examples are provided. Changes have created better data quality and improved the station performance. Vigilance and deployment of service teams to reestablish communications, replace noisy sensors, and troubleshoot problems is also key to maintaining the high-quality TA network.