less than the minimum acceptable value then a correction step 162 calculates a quantity an increase current channel gain by g step 164 is performed and then the system processor 68 returns to the outer loop 132 for the selected tri cell the algorithm tests each mask once per channel for six channels and then tests each of four banks of six channels for each of five tries the algorithm then compares the results of the five tries each of the twenty four channels if a test step 166 indicates three or more times that the mask a has the largest value of e a set mask step 168 for that channel selects photodetector a as the one providing the strongest signal if a test step 170 indicates three or more times that the mask b has the largest value of e a set mask step 172 for that channel selects photodetector b as the one providing the strongest signal if a test step 174 indicates three or more times that the mask c has the largest value of e a set mask step 176 for that channel selects photodetector a as the one providing the strongest signal the outer loop 132 has a variable index so that processor duty cycle usage algorithm efficiency can be traded against algorithm accuracy typical test results demonstrated that three passes were sufficient to insure adequate accuracy for most applications of the sensor system 10 the structures and methods disclosed herein illustrate the principles of the.