Pseudolites (PL) are used in a variety of situations, both to augment the GPS based navigation and also to navigate entirely without GPS.  At least four pseudolite transmitters are used to illuminate the region of interest, if navigation without GPS is necessary.

These pseudolites can thus be used to navigate in indoor conditions, urban canyons or in other GPS obscured situations.  These can also be used for augmentation of GPS, improving accuracies, such as those required for precision approach and landing, etc.

In order to meet the diverse applications using an unified architecture, CRS developed a software-based pseudolite system that offers unprecedented flexilibty and reconfigurability.