JPL sequences or JPL codes consist of two linear feedback shift registers (LFSRs) whose code sequence lengths La and Lb must be prime (relatively prime).
Areas of application include distance measurements utilizing spread spectrum signals for satellites and in space technology.
They are also utilized in the more precise military P/Y code used in the Global Positioning System (GPS).
Their major advantage is, that they produce relatively long sequences with only two LFSRs, which makes it energy efficient and very hard to detect due to huge spreading factor.
The same structure can be used to realize a dither generator, used as an additive noise source to remove a numerical bias in digital computations (due to fixed point arithmetics, that have one more negative than positive number, i.e. the mean value is slightly negative).