A systematic method for acquiring positioning signals, such as global positioning
system (GPS) signals, uses different signal detection algorithms at different stages
of signal detection. For example, a method for detecting multiple positioning signals
may include first detecting a first positioning signal using a robust but less
sensitive signal detection method, such as non-coherent integration. Based on the
signal parameter values that allow detection of the first positional signal, detecting
a second positioning signal using a more sensitive method, such as coherent integration.
In this manner, by capturing the strongest signal first using a robust method,
signal detection parameter values common to positioning signals can be narrowed
to allow subsequent signal acquisitions using a more sensitive—but computationally
more intensive—method.