A measuring system includes a first measuring device and a second measuring device. The measuring system is configured to, between the first measuring device and the second measuring device, determine a first phase shift at a first frequency, determine a second phase shift at a second frequency, and determine a third phase shift at a third frequency. The first measuring device includes a phase difference calculator configured to calculate a first phase difference between the first phase shift and the second phase shift, and a second phase difference between the second phase shift and the third phase shift. The first measuring device also includes a range/velocity calculator configured to determine a first biased distance estimate from the first phase difference, a second biased distance estimate from the second phase difference, and an unbiased distance and/or velocity from the first biased distance estimate and the second biased distance estimate.