DME Transponder Self-Verification via Pseudo Interrogation

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Solution Overview

Problem

Conventional distance measuring equipment (DME) performance verification is time-consuming and costly, requiring dedicated jigs and facilities, which hinders efficient operation and increases costs.

Innovation Solution

A DME system with a monitoring processor that generates pseudo interrogations to verify transponder performance, allowing for efficient detection of anomalies and improved verification efficiency without the need for dedicated equipment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional DME performance verification methods are used, then measurement accuracy is ensured, but verification time and cost increase significantly

Engineering Contradiction:
Improvetransponder performance verification accuracyVSAvoidverification time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The monitoring processor generates pseudo-interrogations that replicate the format and structure of actual aircraft interrogations. These pseudo-interrogations are copied from standard interrogation templates, allowing the transponder to be tested with realistic signal patterns without requiring actual aircraft or complex test facilities, thus reducing verification time while maintaining accuracy

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The DME system performs self-verification by having its monitoring processor generate and analyze pseudo-interrogations internally. The system tests its own transponder using self-generated test signals, eliminating the need for external dedicated verification equipment and reducing both time and cost requirements for performance verification

Inventive Principle:
Principle #25Self-service

2Reliability

If dedicated verification jigs and facilities are used, then verification reliability is improved, but device complexity and cost increase

Engineering Contradiction:
Improveperformance verification reliabilityVSAvoidverification equipment complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The monitoring processor serves multiple functions: it generates pseudo-interrogations for transponder testing, analyzes the transponder's replies, and performs performance evaluation. This multi-functional approach eliminates the need for separate dedicated verification equipment, reducing device complexity while maintaining verification reliability through integrated self-testing capabilities

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

Instead of requiring physical copies of actual interrogation signals from aircraft, the system creates digital copies through pseudo-interrogations generated by the monitoring processor. These synthesized test signals replicate the essential characteristics of real interrogations, providing reliable verification without complex external facilities

Inventive Principle:
Principle #26Copying

3Productivity

If pseudo-interrogations are generated for verification, then verification efficiency is improved, but signal format precision requirements increase

Engineering Contradiction:
Improveverification efficiencyVSAvoidpseudo-interrogation signal format precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The monitoring processor generates pseudo-interrogations with precisely controlled parameters including pulse width, pulse spacing, and timing intervals that match standard DME interrogation specifications. By carefully adjusting these signal parameters to conform to established formats, the system achieves high verification efficiency while maintaining the precision required for accurate transponder performance evaluation

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP2267479B1Distance measuring equipment and distance measuring equipment monitor system
Publication Date: 2016.03.16 KK TOSHIBA
  • EP2267479B1 patent drawingFigure 1~2
  • EP2267479B1 patent drawingFigure 3(a)~3(b)
  • EP2267479B1 patent drawingFigure 4

AI summary

A transponder (12) transmits a reply in response to an interrogation input thereto, the interrogation including twin pulses, and a monitoring processor (13) transmits to the transponder a pseudo interrogation identical in format to the interrogation, receives from the transponder a reply responding to the pseudo interrogation, and monitors a performance of the transponder, the monitoring processor (13) including a pulse spacing adjuster (131c) operable to adjust a pulse spacing of twin pulses along with generation of the pseudo interrogation, and a monitor (134b) operable to output an alarm in response to a failed reception or a delayed reception of a reply from the transponder after transmission of a pseudo interrogation with a compliant pulse spacing, and further to output an alarm in response to a reception of a reply from the transponder after transmission of a pseudo interrogation with an uncompliant pulse spacing.