The minima section of an RNAV or GPS approach chart looks like a bowl of alphabet soup. Full of ever-changing acronyms, it’s hard for the weekend flyer to keep up. To help, I studied the AIM and compiled this at-a-glance list of GPS approach minima and what they mean to you.
|GLS||GNSS Landing System||GLS uses LAAS (Local Area Augmentation System) to provide ILS-like lateral and vertical guidance. GLS is still under development|
|LPV||Localizer Performance with Vertical Guidance||Uses WAAS to provide ILS-like lateral and vertical guidance. Minimums will be slightly higher than GLS|
|LNAV/VNAV||Lateral Navigation with Vertical Navigation||Vertical guidance provided by a barometric altimeter based system or WAAS GPS|
|LP||Localizer Performance||Localizer-like performance provided by a WAAS capable GPS. No vertical guidance|
|LNAV||Lateral Navigation||Step-down non precision approach with no vertical guidance. Any GPS certified for IFR approaches can fly to LNAV minimums|
All of this information and more is in the latest Airman Information Manual. For the 2013 manual, check pages 5-4-21 and 5-4-22.