This approach shows two sets of minimums that both have vertical guidance with a Decision Altitude (DA). What is the difference between LNAV/VNAV and LPV, and why does LPV have lower minimums?
There's an FAA paper on RNAV approaches that explains the differences between LP, LPV, LNAV and LNAV/RNAV approaches. I made a table for my own reference but since StackExchange doesn't allow tables (AFAIK) here's a summary:
- LP: no vertical guidance; WAAS required; MDA for minimums
- LPV: vertical guidance; WAAS required; DA for minimums
- LNAV: no vertical guidance; WAAS not required; MDA for minimums; requires RAIM integrity if WAAS is not available
- LNAV/VNAV: vertical guidance; WAAS or baro-VNAV required; DA for minimums; requires RAIM integrity if WAAS is not available (i.e. if using baro-VNAV); possible temperature restrictions if using baro-VNAV
The difference between LPV and LNAV/VNAV is that although they both have vertical guidance, LPV was intentionally designed to be very similar to an ILS approach with an increasingly sensitive glideslope whereas LNAV/VNAV was not. Other answers have additional comments about LNAV/VNAV having been designed earlier and for different equipment which would certainly make sense.
LNAV/VNAV approaches were originally designed for larger, more sophisticated turbine aircraft utilizing onboard Flight Management Systems (FMS). These types of approaches uses barometric altimeters and ground radio equipment to compute a descent path and add vertical guidance to an existing non-precision approach.
An LPV approach still provides vertical guidance but is not a precision approach. In this type of approach WAAS GPS satellite and ground-based data are used to provide the aircraft with the vertical descent information.
Usually a WAAS approved GPS navigator, like the Garmin 430w, is capable of flying both LPV and LNAV/VNAV approaches.
LPV is a higher precision approach requiring equipment beyond what is needed for LNAV/VNAV. In particular you need dual WAAS recievers in a certified installation. The improved guidance is what allows the lower DH. See this link for more information.
. A LPV approach can provide WAAS vertical guidance as low as 200 feet AGL. LNAV/VNAV approaches also provide approved vertical guidance and existed before the WAAS system was certified. At that time, only aircraft equipped with a flight management system (FMS) and certified baro-VNAV systems could use the LNAV/VNAV minimums. Also the design of an LPV approach incorporates angular guidance with increasing sensitivity as an aircraft gets closer to the runway. (This is intentional to aid pilots in transferring their ILS flying skills to LPV approaches).
LPV - Localizer Performance with Vertical Guidance is some kind of enhanced satellite navigation with an required accuracy of 16 meters in the horizontal and 20 meters in the vertical plane during 95 percent of the time, achieved by multiple special GPS (WAAS) receivers. Obviously this accuracy allows to reduce the minima on the approaches.
In order to get the LPV minima you need:
1 - An approach certified SBAS/WAAS capable receiver
2 - That the GPS+SBAS signals are good enough for LPV approach (horizontal and vertical protection levels low enough)
If you have an approach certified GPS receiver without WAAS, then no LPV/LP for you, but there are still the possibility of getting a VNAV or a pure LNAV approach depending on your installation and GPS signal quality.
In essence you will always automatically get the best minima possible. The receiver will tell you which one automatically.
Look up the documentation for your GPS receiver.
Dual receveivers are NOT required !
There is also the possibility of getting an LPV, but with a higher DH/same visibility if the signal quality is within LPV250 but outside LPV requirements.
Read below with a grain of salt, as I'm not a CFII.
From what I understand, there are no "precision" GPS approaches, aside from CAT1,2,3.
LPV is more accurate, uses WAAS, and means LP with vertical guidance.
LNAV/VNAV is an older tech, and was originally designed before WAAS was available. Before WAAS, aircraft with flight management/director systems were equipped to fly LNAV/VNAV. The VNAV portion consisted of Baro-VNAV equipment requirements. Nowadays, you can buy some newer aircraft equipped with Baro-VNAV, or fly those approaches with capable WAAS GPS.
Either way, you should read your aircraft manual and check it's equipment and what approaches it's qualified for.
Here's a link to more info I found.