There's no set limit, it depends on the power of the laser and the sensitivity of the receiver.

Selectivity can mean a couple of things. It could be mean being selective or when an electronic receiver is selective. Likewise, sensitivity could mean the act of being sensitive or how a receiver or instrument responds to signals or to change the strength or to change the signal all together.

Some of the key features for the Raymarine RS130 GPS receiver are, very high sensitivity -162dBm,

These are the 3 criteria in choosing a good receiver. Sensitivity refers to the ability of the receiver to receive very weak signal. Selectivity to select the desired frequency and reject the others. lastly, Fidelity to produce good quality of signal without distortion.

A receiver test set is a device used to measure and evaluate the performance of a communication receiver. It can generate test signals and measure key parameters such as sensitivity, selectivity, and dynamic range of the receiver to ensure it meets specified requirements and standards. This tool is commonly used in the manufacturing and maintenance of communication equipment.