WAAS Performances

WAAS
Title	WAAS Performances
Author(s)	GMV.
Level	Basic
Year of Publication	2011

The Wide Area Augmentation System (WAAS) is an GPS Augmentation system developed by the Federal Aviation Administration (FAA), with the goal of improving its accuracy, integrity, and availability. Essentially, WAAS is intended to enable aircraft to rely on GPS for all phases of flight, including precision approaches to any airport within its coverage area.

WAAS Performances

Performances are usually described in terms of accuracy, integrity, availability and continuity. The WAAS specification Performance Requirements are different depending on the phase of the flight: en route through 1) Non-precision approach (NPA) and 2) Precision Approach.

1. WAAS Performance Requirements for Non-Precision Approach are summarized in the following table:{| class="wikitable" align="center"

! Performance Requirement ! Total System ! Navigation System ! WAAS Signal-in-Space ! Airborne |- align="center" ! Availability | 0.999 | 0.999 | 0.999 | Not Specified (N/S) |- align="center" | Accuracy
95% Horizontal Position
99.999% Horizontal Position
95% Vertical Position
95% Pseudorange |
N/S
N/S
N/A
N/A |
100 m
500 m
N/A
N/S |
N/S
N/S
N/A
N/S |
N/S
N/S
N/A
1.2 m |- align="center" | Integrity
Integrity Risk
Time-to-Alarm |
N/S
10 s |
N/S
10 s |
10e-7/hour
8 s |
N/S
2 s |- align="center" | Continuity
Continuity of Navigation
Continuity of Fault Detection |
1 - 10e-5/hour
1 - (2x10e-5)/hour |
1 - 10e-5/hour
1 - (2x10e-5)/hour |
1 - 10e-8hour
1 - 10e-5/hour |
1 - 10e-5/hour
1 - 10e-5/hour |}

1. WAAS Performance Requirements for Precision Approach are summarized in the following table: