Madiha Jafri

Graphical and statistical analysis of airplane passenger cabin RF coupling paths to avionics

Portable wireless technology provides many benefits to modern day travelers. Over the years however, numerous reports have cited portable electronic devices (PEDs) as a possible cause of electromagnetic interference (EMI) to aircraft navigation and communication radio systems. PEDs may act as transmitters, both intentional and unintentional, and their signals may be detected by the various radio receiver antennas installed on the aircraft. Measurement of the radiated field coupling between passenger cabin locations and aircraft communication and navigation receivers, via their antennas is defined herein as interference path loss (IPL). IPL data is required for assessing the threat of PEDs to aircraft radios, and is very dependent upon airplane size, the interfering transmitter position within the airplane, and the location of the particular antenna for the aircraft system of concern. NASA Langley Research Center, Eagles Wings Inc., and United Airlines personnel performed extensive IPL measurements on several Boeing 737 airplanes. This paper provides a graphical and statistical analysis of IPL data measured onboard two Boeing 737 airplanes. The analysis reveals valuable insight into EMI field propagation characteristics, measurement repeatability, selection of test equipment, and interpretation of measurement data related to IPL.

Graphical analysis of B-737 airplane pathloss data for GPS and evaluation of coupling mitigation techniques

The use of portable electronic devices (PEDs) onboard commercial airliners is considered to be desirable for many passengers. However, the possibility of electromagnetic interference (EMI) caused by these devices may affect flight safety. PEDs may act as transmitters, both intentional and unintentional, and their signals may be detected by the various navigation and communication radios onboard the aircraft. Interference pathloss (IPL) is defined as the measurement of the radiated field coupling between passenger cabin locations and aircraft communication and navigation receivers, via their antennas. The paper first focuses on IPL measurements for GPS, taken on an out-of-service United Airlines B-737-200. IPL pattern symmetry is verified by analyzing data obtained on the windows of both the port and starboard sides of the aircraft. Further graphical analysis is performed with the door and exit seams sealed with conductive tape in order to understand better the effects of shielding on IPL patterns. Shielding effects are analyzed from window data for VHF and LOC systems. In addition, the shielding benefit of applying electrically conductive film to aircraft windows is evaluated for GPS and TCAS systems.

Comparative analysis of interference path loss coupling patterns on B-737 vs B-757 airplanes

Portable wireless technology provides many benefits to modern day travelers. The objective of this paper is to analyze IPL measurement data, to better understand the impact on coupling levels based on the different locations of the aircraft radio antennas on B-757 and B-737 airplanes, and to provide a basis for future fuzzy logic modeling of airplane IPL. This effort will build upon previous fuzzy modeling of IPL data for B-737 airplane data (Jafri, 2004).

Fuzzification of electromagnetic interference patterns onboard commercial airliners due to wireless technology

The use of portable wireless technology has increased dramatically over the past few years. Over the years however, numerous reports have cited portable electronic devices (PED) as a possible cause of electromagnetic interference (EMI) to aircraft navigation and communication radio systems. PED may act as transmitters and their signals may be detected by the various radio receiver antennas installed on the aircraft. Measurement of the radiated field coupling between passenger cabin locations and aircraft communication and navigation receivers, via their antennas is defined herein as interference path loss (IPL). Personnel from NASA Langley Research Center, Eagles Wings Incorporated, and United Airlines performed extensive IPL measurements on several Boeing 737 airplanes. In previous work, the IPL data collected was graphically plotted and presented using MATLAB. This paper provides an introductory result of modeling EMI patterns using fuzzy logic, using the graphical analysis of IPL data. The application of fuzzy logic seeks to provide a means of estimating IPL at various locations within an airplane passenger cabin using simple modeling parameters. Fuzzy logic methods may provide a means to assess IPL characteristics of aircraft that have not been subject to expensive measurement or modeling processes and may also be useful for estimating the merit of aircraft design changes intended to minimize the potential for EMI.

Classification and Prediction of Interference Pathloss Measurements Inside B-757 Using Feed Forward Neural Networks (Prepared December 2005)

Neural network modeling is introduced in this paper to classify and predict interference pathloss measurements on a Boeing 757 airplane. Interference patterns inside the aircraft are classified and predicted based on the locations of the doors, windows, aircraft structure and the aircraft system-of-concern. Modeled results are compared with measured data and a plan is proposed to enhance the modeling for better prediction of electromagnetic coupling problems inside aircraft

Interference Path Loss Prediction in A319/320 Airplanes Using Modulated Fuzzy Logic and Neural Networks

In this paper, neural network (NN) modeling is combined with fuzzy logic to estimate Interference Path Loss measurements on Airbus 319 and 320 airplanes. Interference patterns inside the aircraft are classified and predicted based on the locations of the doors, windows, aircraft structures and the communication/navigation system-of-concern. Modeled results are compared with measured data. Combining fuzzy logic and NN modeling is shown to improve estimates of measured data over estimates obtained with NN alone. A plan is proposed to enhance the modeling for better prediction of electromagnetic coupling problems inside aircraft.

Classification and Prediction of RF Coupling Inside A-320 and A-319 Airplanes using Feed Forward Neural Networks

Neural network modeling is introduced in this paper to classify and predict interference path loss measurements on Airbus 319 and 320 airplanes. Interference patterns inside the aircraft are classified and predicted based on the locations of the doors, windows, aircraft structures and the communication/navigation system-of-concern. Modeled results are compared with measured data and a plan is proposed to enhance the modeling for better prediction of electromagnetic coupling problems inside aircraft

Graphical analysis of electromagnetic coupling on B-737 and B-757 aircraft for VOR and LOC IPL data

The objective of this paper is to analyze the IPL data measured, to better understand the impact on coupling levels based on the different locations of the aircraft radio antennas on the B-757 and B-737 airplanes, and to provide a basis for future fuzzy logic modeling of airplane IPL. This effort will build upon previous fuzzy modeling of IPL data for B-737 airplane data. Systems studied and compared include the instrument landing system localizer (LOC) and VHF omniranging (VOR) system.

Prediction of interference pathloss inside b-737 and b-757 using modulated fuzzy logic and neural networks

Not available for publication.

Graphical representation of the effects of antenna locations on path loss data [aircraft EMI]

The use of portable wireless technology has increased dramatically over the past few years. This increased use has caused a heightened concern for electromagnetic interference from wireless-enabled technologies, such as laptop computers and cellular phones to aircraft communication and navigation radios. Researchers at NASA Langley Research Center, United Airlines and Eagles Wings Incorporated, have tested and collected interference path loss data on a United out-of-service B737 aircraft near Victorville, CA. This paper summarizes the results found from the measured data sets as well as includes graphical representations of the interference path loss data on a B737 plane with different system antennas.