GPS and INS theory and operating characteristics

T-45C TS INav-02

Introduction to INav and Voice Procedures

(2) VOR/DME: possible, depending upon

facilities

Errors

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TACAN 40 Degree

(1) TACAN: locks on in increments of 40

Lock-on Error

degrees from actual bearing

(2) VOR/DME: N/A

IV.

GPS and INS theory and operating characteristics

Sg 9, fr 5

Lesson Organization

GPS 2.1.10.1.1.1.1.

THEORY: GPS is a 24+ satellite-based navigation,

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positioning, and time transfer system. GPS satellites

Global Positioning

transmit identity, calibration, and time signals. Aircraft

System (GPS)

use passive receivers to process that satellite data.

Triangulation and sensed aircraft flight path angles are

used to compute aircraft position. Altitude can also be

extrapolated using GPS signals

NOTE: The T-45C does not use GPS to generate

cockpit altitude information. The T-45C GPS and

INS are linked together in the Global Positioning

System/Inertial Navigation Assembly (GINA).

GPS receivers process satellite signal time-delay

measurements to determine satellite-to-aircraft

range

U.S. GPS system is operated by DoD from Falcon

AFS, CO and some overseas backup sites

GPS can serve an unlimited number of properly

equipped users, worldwide

GPS signal strength is reduced somewhat by heavy

weather, but not enough to interfere with data

reception

The U.S. GPS was certified as having initial

operational capability (IOC) in Dec 93. Was partially

functional during Desert Storm (1991), and earlier

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