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Storm Cell Lighting Positional Sensor System

IP.com Disclosure Number: IPCOM000236212D
Publication Date: 2014-Apr-11

Publishing Venue

The IP.com Prior Art Database

Abstract

Aircraft travel in inclement weather that produces lighting is a common hazard. Lighting sensors are mature enough to provide good azimuth angular information of the lighting strike with respect to the sensor but do not provide good enough range detection due to a very large variation in EM field. Only air to ground lighting strikes will be modeled because of their narrow azimuth resolution and ease of mathematical modeling since long, cloud to cloud lightning events complicate the mathematical analysis in this paper. An analog to digital converter with fixed sampling rate on the order tenths of nanoseconds may be required in order to separate in time the detections of the two sensors separated by a characteristic distance such as a wingspan of an aircraft. We have chosen a wingspan sensor alignment by placing two inline lighting sensors, one in each wing tip of the aircraft separated by distance, W, in meters.

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Storm Cell Lighting Positional Sensor System

Introduction:

Aircraft travel in inclement weather that produces lighting is a common hazard. Lighting sensors are mature enough to provide good azimuth angular information of the lighting strike with respect to the sensor but do not provide good enough range detection due to a very large variation in EM field. Only air to ground lighting strikes will be modeled because of their narrow azimuth resolution and ease of mathematical modeling since long, cloud to cloud lightning events complicate the mathematical analysis in this paper. An analog to digital converter with fixed sampling rate on the order tenths of nanoseconds may be required in order to separate in time the detections of the two sensors separated by a characteristic distance such as a wingspan of an aircraft. We have chosen a wingspan sensor alignment by placing two inline lighting sensors, one in each wing tip of the aircraft separated by distance, W, in meters.

We assume the lighting detection systems has two lighting sensors connected to a computer unit that has digital converters with time resolution in the fractions of nanoseconds, we can claim we can detect the range of the lighting strike with respect to the position of the aircraft sensors in the aircraft and the lighting strike. The lighting sensors will provide the times of arrival of the signal in a nanosecond resolution, and the positional azimuth angles of the lighting strike with respect to the sensors. The sensors signals are being timed by a synchronized analog to digital converters (A2D) clock with fractional nanosecond resolution. Let t0 define the time the lighting strikes within the storm cell, t1 define the time the lighting electromagnetic pulse reaches the left (or pilot's side) wing sensor and t2 define the time the electromagnetic pulse reaches the right wing sensor.

The characteristic time delay along the sensor separation is given by W/c (~ 10-7 seconds where W is a typical wingspan of an aircraft, say ~ 30 m). The characteristic distance traveled by a jet aircraft with constant cruising speed, V (at 500 knots), is equal to V*W/c (about 0.02 mm). Therefore the distance traveled by the aircraft does not need to be of any concern for any strike detection system. This article will discuss the mathematical model that can be used to derive the angular resolution data required due to the lighting (air to ground) in a storm cell and a wing span positional sensor system, in the Appendix 1 other a sensors alignment are considered: a nose to tail alignment, a nose-wing tip alignment, and finally a nose and extended tail alignment. In Appendix 2 the MATLAB code to produce the figures in this article is shown.

Background

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Technical Discussion

Wingspan Alignment

The wingspan alignment, the sensors are located on the wings and their separation distance is given by W, the wingspan. The Cartesian plane under consideration is defined by the triang...