## The blocklibrary NAVLIB

The FDC blocklibrary NAVLIB contains radio-navigation blocks for Simulink. Currently, there are two sublibraries, one for ILS signals and one for VOR signals. ILS stands for Instrument Landing System; VOR means 'Very high frequency Omnidirectional Range'. If desired, this library could be enhanced with other radio-navigation blocks, such as Global Positioning System. A detailed theoretical description about these simulation models can be found in the references at the end of this page.

The ILS sublibrary contains the following blocks:

- ILS (Nominal ILS signals)
  ILS signals without noise and/or steady-state errors
- GSerr
  Glideslope steady-state errors according to ICAO guidelines
- GSnoise1
  Glideslope noise according to AGARD R-632 (ref.[2])
- GSnoise2
  Glideslope noise according to NASA CR-2022 (ref.[3])
- LOCerr
  Localizer steady-state errors according to ICAO guidelines
- LOCnoise1
  Localizer noise according to AGARD R-632 (ref.[2])
- LOCnoise2
  Localizer noise according to NASA CR-2022 (ref.[3])
- ILS example
  Example system which demonstrates the practical use of the other ILS blocks

The VOR sublibrary contains the following blocks:

- VOR (Nominal VOR signals)
  VOR signals without error components
- VORerr
  Steady-state error for the VOR signal
- VOR example
  Example system which demonstrates the practical use of the other VOR blocks

Note: currently there are no accurate noise models available for the VOR blocks. Should such models become available, they can easily be included in the VOR sublibrary of NAVLIB.

### References

Apart from the FDC user-manual, the following reference contains 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 (also contained in the STAR database of NASA, report number NONP-NASA-SUPPL-DK-94-28027)
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