Low Probability of Detection/Intercept
This is my first post on this forum.
I have often seen the terms "low probability of intercept" (LPI) and "low probability of detection" (LPD) used within the same sentence (and often stated "LPI/LPD") when describing active sensors and datalinks. What is the difference between these two concepts, or are they essentially synonymous? (In the interest of saving responders' time and effort, I understand, at least at a layman's level, concepts like frequency-hopping, directional antennae, narrow beam width, etc., and that these features might make a sensor/datalink difficult to detect or intercept).