GPS Approach Minimums
It is easy to get confused by the variety of published minimums on GPS approach procedures. Selecting the right one for the conditions and aircraft equipment is extremely important because each are fundamentally different. Let's start by reviewing the different types of minimums followed by practical application of each.
LNAV - Think of this minimum as the same found on your typical VOR or LOC approach. It is a classic 'dive and drive' approach descending from the FAF to the MDA with no vertical guidance. Once reaching the MDA the pilot is expected to level off and hopefully acquire the runway environment to visually land using normal maneuvering.
LNAV/VNAV (LNAV+V) - These minimums add an additional layer of safety by computing a VDA, or vertical descent angle, from the FAF to the TCH. This means you can fly a continuous descent final approach (CDFA) similar to an ILS. There is no vertical path signal but depending on your aircraft equipment the GPS receiver can calculate the vertical path using information coded in the approach data.
LPV - Lateral and Precision Vertical minimums can be used by WAAS receivers which improve position accuracy and provide both lateral and vertical guidance, much like an ILS. This is why LPV are considered precision approaches whereas the other minimums are not, despite the vertical guidance.