While watching test missions from the Mission Control Centers, our customer experienced telemetry data drop outs from legacy fixed telemetry trackers due to line of sight and RF multipath issues when test aircraft were taxiing out for take off. Arcata engineers designed and built a mobile telemetry tracking system that was installed along the taxiway to eliminate drop outs. Arcata engineers are now working to upgrade the telemetry system by integrating a Best Telemetry Source Selector (BSS), which will input telemetry data from up to 8 telemetry sources and identify the best source to provide to the Mission Control Centers.