For the past three years , the MIT Haystack Observatory and the broadband team have been developing a proof - of - concept broadband geodetic VLBI microwave ( 2 - 12 GHz ) receiver . Also on - going at Haystack is the development of post - correlation processing needed to extract the geodetic observables . Using this processing , the first fully - phase - calibrated geodetic fringes have been produced from observations conducted with the proof - of - concept system . The results we present show that the phase - calibrated phase residuals from four 512 MHz bands spanning 2 GHz have an RMS phase variation of 8deg which corresponds to a delay uncertainty of 12 ps .