## The radio-navigation subsystem GSnoise

The sublibrary ILS of the library NAVLIB contains two different masked subsystem blocks which implement glideslope noise signals: GSnoise1 and GSnoise2. See the references below for more details about the theoretical backgrounds.

Other blocks in the ILS sublibrary of NAVLIB are: Nominal ILS signals, GSerr, LOCerr, and LOCnoise, and the example system ILS example.

### GSnoise1

This block generates glideslope noise according to AGARD R-632, assuming a constant approach speed. The user must specify the scale length Lgs (typically 85 m), the standard deviation sigma_gs (usually <= 15 micro-Ampere), and the approach speed V.
GSnoise1 doesn't have any inputs.
Outputsignal: Glideslope-noise [micro-Ampere]

### GSnoise2

This block uses a glideslope noise filter according to NASA CR-2022. The user doesn't have to specify any parameters.
GSnoise2 doesn't have any inputs.
Outputsignal: Glideslope-noise [micro-Ampere]

### References

Apart from the FDC user-manual, the following references contain more information about the ILS signals:

1. 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
2. Anon.: Approach and Landing Simulation. AGARD report 632, Ames, 1975
3. Johnson, W.A., McRuer, D.T.: Development of a Category II Approach System Model. NASA Contractor Report 2022, Washington D.C., USA, 1972