Bistatic DIAL for multi-species aviation pollutant measurements from RPAS

This paper presents the conceptual design of a new low-cost measurement system for the determination of pollutant concentrations associated with aircraft operations. The proposed system employs Light Detection and Ranging (LIDAR) and passive electro-optics equipment installed in two non-collocated components. The source component consists of a tuneable small-size and low-cost/weight LIDAR emitter, which can be installed either on airborne or ground-based autonomous vehicles, or in fixed surface installations. The sensor component includes a target surface calibrated for reflectance and passive electro-optics equipment calibrated for radiance, both installed on an adjustable support. The proposed bistatic system determines the column-averaged molecular and aerosol pollutant concentrations along the LIDAR beam by measuring the cumulative absorption and scattering phenomena along the optical slant range. The molecular column densities are measured by means of Differential Absorption LIDAR (DIAL), which exploits the known molecular vibration processes for non-ambiguous species detection. Aerosol concentrations such as particulate and soot are determined by means of knowledge-based inversion with regularization. The laboratory calibration of the system components is also discussed. Previously published uncertainty analysis results highlighted the positive qualities of the proposed measurement system even in degraded meteorological conditions, making the proposed bistatic LIDAR a viable alternative to other systems currently employed

Orbital and meteorological factors pertinent to satellite transmissions of facsimile weather charts Final report

Automatic picture transmission system on Nimbus and earth synchronous satellites for transmission of weather chart

Bistatic LIDAR system for the characterisation of aviation-related pollutant column densities

In this paper we investigate an innovative application of Light Detection and Ranging (LIDAR) technology for aviation-related pollutant measurements. The proposed measurement technique is conceived for the high-resolution characterisation in space and time domains of aviation-related pollutant gases. The system performs Integral Path Differential Absorption (IPDA) measurement in a bistatic LIDAR measurement setup. The airborne component consists of a tuneable Near Infrared (NIR) laser emitter installed on an Unmanned Aircraft (UA) and the ground sub-system is composed by a target reference surface (calibrated for reflectance) and a differential transmittance measuring device based on a NIR Camera calibrated for radiance. The specific system implementation for Carbon Dioxide (CO2) measurement is discussed. A preliminary assessment of the error figures associated with the proposed system layout is performed

Multi-objective optimisation of aircraft flight trajectories in the ATM and avionics context

The continuous increase of air transport demand worldwide and the push for a more economically viable and environmentally sustainable aviation are driving significant evolutions of aircraft, airspace and airport systems design and operations. Although extensive research has been performed on the optimisation of aircraft trajectories and very efficient algorithms were widely adopted for the optimisation of vertical flight profiles, it is only in the last few years that higher levels of automation were proposed for integrated flight planning and re-routing functionalities of innovative Communication Navigation and Surveillance/Air Traffic Management (CNS/ATM) and Avionics (CNS+A) systems. In this context, the implementation of additional environmental targets and of multiple operational constraints introduces the need to efficiently deal with multiple objectives as part of the trajectory optimisation algorithm. This article provides a comprehensive review of Multi-Objective Trajectory Optimisation (MOTO) techniques for transport aircraft flight operations, with a special focus on the recent advances introduced in the CNS+A research context. In the first section, a brief introduction is given, together with an overview of the main international research initiatives where this topic has been studied, and the problem statement is provided. The second section introduces the mathematical formulation and the third section reviews the numerical solution techniques, including discretisation and optimisation methods for the specific problem formulated. The fourth section summarises the strategies to articulate the preferences and to select optimal trajectories when multiple conflicting objectives are introduced. The fifth section introduces a number of models defining the optimality criteria and constraints typically adopted in MOTO studies, including fuel consumption, air pollutant and noise emissions, operational costs, condensation trails, airspace and airport operations

4-dimensional trajectory generation algorithms for RPAS mission management systems

This paper presents the algorithms enabling real-time 4-Dimensional Flight Trajectory (4DT) functionalities in Next Generation Mission Management Systems (NG-MMS), which are the core element of future Remotely Piloted Aircraft Systems (RPAS) avionics. In particular, the algorithms are employed for multi-objective optimisation of 4DT intents in various operational scenarios spanning from online strategic to tactical and emergency tasks. The adopted formulation of the multi-objective 4DT optimisation problem includes a number of environmental objectives and operational constraints. In particular, this paper describes the algorithm for planning of 4DT based on a multi-objective optimisation approach and the generalised expression of the cost function adopted for penalties associated with specific airspace volumes, accounting for weather, condensation trails and noise models

The effects of tube deformities on the dynamic calibration of a tubing system

Using the Berge and Tijdemen method for tube calibration is powerful as it allows for tubes of various dimensions to be used in a dynamic pressure data acquisition system by using post-processing methods to calibrate for the tubes natural dynamic response. Knowing the tubes response and using the inverse Fourier transform to calibrate the tube system is accepted however knowing how tube deformities influence this calibration is not known. Small singular deformities caused by pinch, twist and bending, which corresponded to a pinch and internal area ratios less than approximately 5 and 3.57 respectively, do not affect the tubing response of a system. Significant effects on the tubes response only occur at pinch and area ratios above these values. Furthermore, pinching ratios above 5 are extreme and represent a tube that is pinched locally to the point where it is almost blocked. This is testament to the tubes resilience to local and internal diameter changes. It can be safely assumed that unwanted and unexpected dampening of a tubing system could be due to a local tube deformity