Apparatus and method for detecting an interference radiation on board of an aircraft

• US 5,970,395 A
• Filed: 07/18/1997
• Issued: 10/19/1999
• Est. Priority Date: 07/18/1996
• Status: Expired due to Term

• Current Assignee: Daimlerchrysler North America Corporation (Mercedes-Benz Group AG)
• Original Assignee: Daimlerchrysler North America Corporation (Mercedes-Benz Group AG)
• Inventors: Hildebrandt, Fred, Weiler, Werner, Krumbholz, Michael
• Primary Examiner(s): LOOMIS, PAUL A
• Application Number:
  US08/896,893
• Time in Patent Office: 823 Days
• Field of Search: 455/67.1, 455/67.3, 455/456, 455/457, 455/501, 455/63, 455/132, 455/150.1, 455/431
• US Class Current: 455/67.13
• CPC Class Codes: G01R 29/08 Measuring electromagnetic field characteristics
• CPC Class Codes: G01R 31/001 Measuring interference from external sources to, or emission from, the device under test, e.g. EMC, EMI, EMP or ESD testing measuring electromagnetic fields G01R29/08; circuits for generating HV pulses in dielectric strength testing G01R31/14
• CPC Class Codes: G01R 31/008 on air- or spacecraft, railway rolling stock or sea-going vessels

Abstract

An apparatus for detecting high frequency interference radiation signals, such as radio frequency emissions, on board a passenger aircraft includes at least two receiver units for receiving and measuring the interference radiation signal, and a monitoring unit for evaluating the signal measurement results. Each receiver unit respectively includes at least one antenna, the monitoring unit includes an interference computer, and a digital data signal transmission path connects the receiver units to the monitoring unit. The interference computer evaluates the data signals received from the receiver units to determine the location of an interference radiation source within the aircraft, and indicates corresponding location and warning information on a display unit connected to the interference computer.

Claims

1. A method of detecting and locating a source of an interference radiation on board an aircraft, using an apparatus including a plurality of receiver units each respectively including at least one antenna, a monitoring unit including an interference computer adapted to receive and evaluate digital signals from said receiver units, a digital data transmission pathway linking said receiver units and said monitoring unit and adapted to convey digital signals therebetween, and a display unit connected to an output of said monitoring unit, said method comprising the following steps:

a) receiving an interference radiation in said receiver units with said antennas of said receiver units;

b) in each one of said receiver units, sampling said interference radiation in at least one specified frequency range, and comparing said sampled interference radiation with at least one specified signal level threshold;

c) if said sampled interference radiation exceeds said threshold in said step (b), then preparing and transmitting from said receiver units to said monitoring unit respective digital signals that respectively include at least an identifier of a respective originating one of said receiver units, and first data specifying a respective frequency range and second data specifying a respective signal field strength of said interference radiation as received in said respective originating receiver unit;

d) evaluating and comparing with one another in said monitoring unit said respective digital signals transmitted from said receiver units, and thereby determining a location of a source of said interference radiation; and

e) transmitting from said monitoring unit to said display unit information indicating at least said location of said source of said interference radiation.

2. The method according to claim 1,

wherein each said receiver unit respectively further includes a frequency scanner, a bus transmitting unit, and a bus receiving unit, each said antenna is connected to a respective receiving input of said frequency scanner, said bus transmitting unit is interposed and connected between a signal output of said frequency scanner and said data transmission pathway, and said bus receiving unit is interposed and connected between said data transmission pathway and a signal input of said frequency scanner, and

wherein said sampling and said comparing in said step b) are carried out in said frequency scanner.

3. The method according to claim 2,

wherein said data transmission pathway includes an electrical data bus including an electrical conductor connected to said monitoring unit and to said bus transmitting unit and said bus receiving unit of each said receiver unit, and

wherein said transmitting in said step c) is carried out by said bus transmitting unit which transmits said digital signals as electrical signals via said electrical data bus.

4. The method according to claim 2,

wherein said data transmission pathway includes an optical data bus including an optical conductor connected to said monitoring unit and to said bus transmitting unit and said bus receiving unit of each said receiver unit, and

wherein said transmitting in said step c) is carried out by said bus transmitting unit which transmits said digital signals as optical signals via said optical data bus.

5. The method according to claim 2,

wherein said data transmission pathway is a wireless radio data transmission pathway, and

wherein said transmitting in said step c) is carried out by said bus transmitting unit which transmits said digital signals as radio signals via said wireless radio data transmission pathway.

6. The method according to claim 2,

wherein said data transmission pathway is a wireless infrared data transmission pathway, and

wherein said transmitting in said step c) is carried out by said bus transmitting unit which transmits said digital signals as infrared signals via said wireless infrared data transmission pathway.

7. The method according to claim 2,

wherein each said receiver unit includes a plurality of said antennas that are respectively tuned to different frequency ranges,

wherein said receiving in said step a) comprises receiving said interference radiation in said different frequency ranges respectively with said plural antennas of each said receiver unit,

wherein said sampling in said step b) is carried out in said different frequency ranges, and

wherein said comparing in said step b) is carried out using a plurality of said thresholds respectively for said different frequency ranges.

8. The method according to claims 1,

wherein said monitoring unit further includes a level matrix, a scan control unit, and a scan input unit, said level matrix is connected to a memory input of said interference computer, said scan input unit is interposed and connected between said data transmission pathway and a signal input of said interference computer, said scan control unit is interposed and connected between a signal output of said interference computer and said data transmission pathway, and said level matrix comprises a memory module adapted to store information specifying frequency ranges in which said interference radiation is to be detected and respective signal level threshold values for each of said frequency ranges, and

wherein said method further comprises storing said information specifying said frequency ranges and said signal level threshold values in said memory module.

9. The method according to claim 1,

wherein said antenna is a direction finding antenna adapted and arranged to be rotatable about a substantially vertical axis, and said receiver unit further comprises a rotational drive unit connected to and adapted to rotationally drive said direction finding antenna, and

wherein said method further comprises actuating said rotational drive unit so as to rotate said antenna during said step a).

10. The method according to claim 1, further comprising connecting said receiver units and said monitoring unit to a data bus installed in said aircraft, and using said data bus as said data transmission pathway.

11. The method according to claim 1, further comprising arranging said receiver units above a cabin ceiling panel within a fuselage of said aircraft.

12. The method according to claims 11, wherein said arranging is carried out to position said receiver units spaced apart from one another along a line extending parallel to a lengthwise axis of said aircraft.

13. The method according to claim 11, wherein said arranging is carried out to position said receiver units longitudinally spaced apart from one another in a first direction parallel to a lengthwise axis of said aircraft and laterally spaced apart from one another in a second direction parallel to a crosswise pitch axis of said aircraft.