A CATV station apparatus 100 subjects received optical signals to processes of optical-electrical conversion, signal separation, coupling, and demodulation for obtaining an uplink signal. The system receives a signal from an optical line terminal at an optical network unit and derives an OLT clock. More specifically, compositions including disodium cromoglycate and therapeutic methods that include the pulmonary administration of such compositions are described. At the time the product is to be authenticated, a second measurement is taken, which is compared to the product signature. These teachings extend to more than two transmit antennas. A polynomial correction surface is determined based on a pixel array center, height, and width, surface fitting parameters, and pixel coordinates.