In-flight verification of instrument landing system signals

A method, to enable in-flight verification of an instrument landing system (ILS) transmission, comprising the steps of:

• (a) providing a first output indicative of in-flight reception of an ILS transmission representative of a point in space relevant to a predetermined feature of an ILS approach to a runway;
• (b) utilizing positional information from a source other than said ILS to provide a second output representative of the actual location in space of the point in space indicated by said first output;
• (c) providing a data output representative of ILS approach specification data and usable to determine a spatial characteristic of said feature consistent with accurate ILS operation;
• and
• (d) providing, with use of said first, second and data outputs, an approximation of a level of error regarding said feature of the ILS approach.

A method, to enable in-flight verification of an instrument landing system (ILS) transmission, comprising the steps of:

• (a) providing a first output indicative of in-flight reception of an ILS transmission representative of a point in space relevant to a predetermined feature of an ILS approach to a runway;
• (b) utilizing positional information from a source other than said ILS to provide a second output representative of the actual location in space of the point in space indicated by said first output;
• (c) providing a data output representative of geographical runway location and ILS approach specification data and usable to determine the intended location of said point in space consistent with accurate ILS operation;
• (d) providing, with use of said first, second and data outputs, an approximation of a level of error, regarding said aspect of the ILS approach, representative of a variation between said intended and actual in-space locations and
• (e) providing, in response to said approximation, an indication upon said level of error exceeding a predetermined value.

A system, to enable in-flight verification of an instrument landing system (ILS) transmission, comprising:

• a first unit, responsive to in-flight reception of an ILS transmission, to provide a first output indicative of a point in space representative of a predetermined feature of an ILS approach to a runway;
• a second unit, responsive to received positional data, to provide a second output based at least partially on altitude data and representative of the actual location in space of the point in space indicated by said first output;
• a database access facility arranged to enable access to at least one database to provide a data output representing data usable to determine an intended spatial characteristic of said feature consistent with accurate ILS operation;
• and
• a third unit, responsive to said first, second and data outputs and arranged to provide a discrepancy output representative of a discrepancy between said intended spatial characteristic and said actual location in space.