Abstract: An angular position indicator for cranes which uses a combination of electronic, optical and mechanical components. It is intended for use on fixed or mobile Cranes and designed to operate in harsh industrial environments. Wireless communication replaces fixed electrical hardwiring that would otherwise be required between system components. The angular position indicator uses an angular displacement transducer of unique design. The angular position indicator performs pattern recognition of optical apertures using analog measurements of the illumination of optical detectors. The design allows for a substantial increase in measurement resolution as compared to digital optical encoders with the same number of optical channels.