What is LPV?
A localizer performance with vertical guidance (LPV) approach is a modern instrument approach procedure that uses wide area augmentation system (WAAS) GPS capabilities to attain the most precise position available today. An LPV approach can get a pilot down to a 200-250 feet decision altitude, making it possible for aircraft to land at runways in very low visibility. Without WAAS capabilities, pilots flying in extremely poor visibility conditions might otherwise have to fly to an alternate airport.
LPV approaches and WAAS capabilities in general open up new options for pilots. With properly-equipped aircraft, operators will save time and money by using WAAS as an extremely precise navigational aid. In addition, aircraft pilots will be able to complete landings where they couldn't before, including remote airfields or approaches not easily supported by radio navigation. Instead of relying on radio NAVAIDS, pilots can count on an extremely precise and stable satellite navigation system.
As of November 2012, there were 3,030 LPV approaches published, according to the FAA.
How it Works:
A LPV approach is similar to an LNAV/VNAV approach, but is much more precise and can allow descent to minimums of 200-250 feet. WAAS capabilities are required for precise lateral and vertical guidance, classifying it a precision approach. In fact, an LPV approach is almost identical to an instrument landing system (ILS), but is more accurate and since it utilizes satellite technology, no expensive ground equipment is necessary. This also means the cost is less, as there is no equipment and no regular maintenance needed.
The WAAS takes the error out of typical GPS signals by analyzing the GPS data at a master station and then sending the corrected data information to GPS receivers. The receivers, in turn, are able to remove any GPS errors, making the GPS information even more error-proof and allowing for a more precise result.
Why WAAS is Better:
GPS accuracy is improved from about 100 meters with regular GPS service to about seven meters with WAAS, leaving hardly any room for error, and providing the most precise navigational tool to date.
WAAS will benefit the national airspace system as a whole by increasing capacity, utilizing runways more efficiently, reducing equipment costs both on board and on the ground, and increasing approach capabilities.