Calibration of the Infrared Tully-Fisher Relation and the Global Value of the Hubble Constant

Among existing secondary distance indicators, the IR Tully-Fisher relation is probably the most reliable available for measuring the far flung Hubble flow. Absolute calibration of the method, however, remains highly uncertain owing to the poor state of nearby galaxy distances. A coordinated ground-based and space attack on this problem, primarily involving Cepheids, holds out great promise for a measurement of the Hubble constant good to ten percent.