The radio-navigation subsystem LOCerr
The masked subsystem block LOCerr (Localizer steady-state
errors), which is contained in the ILS-sublibrary of the blocklibrary
NAVLIB, computes the steady-state error
in the localizer signal caused by the ground equipment. The magnitude of
the error is computed according to ICAO guidelines. Both localizer
misalignment and steady-state errors in the localizer sensitivity can be
taken into account. See the references below for
more info about the theoretical backgrounds.
Other blocks in the ILS sublibrary of NAVLIB are: Nominal ILS signals, GSerr, GSnoise, and
LOCnoise, and the example system ILS example.
Inputsignal
Nominal value of localizer current
iloc, [micro-Ampere]
Outputsignal
Localizer current
iloc, including steady-state errors,
[micro-Ampere]
Block-parameters
-
performance category (1, 2, or 3, see the FDC user-manual or ref.[1] for more info)
-
percentage of maximum allowable error in localizer sensitivity
(iloc = Sloc * Gamma_loc, where
iloc is localizer current through cockpit instrument,
Gamma_loc is the angle between the line from projection of
aircraft's c.g. on ground to localizer antenna and runway
centerline, Sloc is the localizer sensitivity)
-
percentage of maximum allowable localizer misalignment
-
distance from runway threshold to localizer antenna, [m]
The block-parameters can be specified in dialog-boxes which appear after
double-clicking the block
LOCerr.
Apart from the FDC user-manual, the following reference contains more information about the ILS signals:
-
M.O. Rauw: A Simulink environment for Flight Dynamics and Control
analysis - Application to the DHC-2 'Beaver', part I:
Implementation of a model library in Simulink. Delft University
of Technology, September 1993 (also contained in the STAR database of
NASA, report number NONP-NASA-SUPPL-DK-94-28027)
-
Anon.: Approach and Landing Simulation. AGARD report 632, Ames,
1975