A computerized ionospheric tomography (CIT) experiment utilizing an array of nine Navy Navigation Satellite System (NNSS) receivers deployed along a north‐south line from South Dakota to south Texas (spanning over 2000 km) is currently underway. The Mid‐America Computerized Ionospheric Tomography Experiment (MACE '93) began collecting data from three receivers deployed in Texas on June 1, 1993. This “short communiqué” presents preliminary results from the ex