Unmanned Aircraft bistatic LIDAR for CO<inf>2</inf> column density determination

Abstract

A novel technique for laser remote sensing of aviation-related atmospheric pollutants from Unmanned Aircraft (UA) platforms is presented. In particular, the paper focuses on Carbon Dioxide (CO 2 ), which is the most important aviation greenhouse gas, and whose column density data can be used for environmental monitoring purposes and to support the development and validation of aircraft engines and Systems for Green Operations (SGO). The proposed measurement techniques are based on a near-infrared bistatic Light Detection and Ranging (LIDAR) system using a modified version of the Integrated Path Differential Absorption (IPDA) technique currently adopted in state-of-the-art (monostatic) remote sensing LIDARs. Target surfaces of known spectral reflectance and Bidirectional Reflectance Distribution Function (BRDF) are irradiated with two laser beams of appropriate wavelengths. The first wavelength is selected in coincidence with one vibrational band of the CO 2 molecule, exhibiting significant absorption phenomena (absorption line). The second wavelength is selected in the same transmission window but outside the absorption line. By measuring the difference in incident energy between the two beams, and inverting the differential transmittance models, it is possible to determine the pollutant column density. Parasite effects include haze, precipitation and dust particulate, which can be modelled as well. In addition to the bistatic LIDAR technique, a monostatic control technique is also proposed in this paper for experimental and calibration purposes.

Real-Time Trajectory Optimisation Models for Next Generation Air Traffic Management Systems

“…Future research will assess the NG-FMS 4DT intent generation and execution performance in perturbed conditions, based on different navigation architectures and in combination with Avionics-Based Integrity Augmentation strategies [15,16]. Novel sensing techniques for aviation related pollutants and atmospheric boundary layer/wake turbulence, currently being researched, will provide valuable inputs for dynamic air traffic optimisation [17,18].…”

Active and Passive Electro-Optical Sensors for Health Assessment in Food Crops

“…Most common DIAL systems are monostatic (single-pulsed), but these require complex and expensive components to detect the very weak backscatter by aerosol particles [ 132 ]. As the bistatic LIDAR layout reduces cost, size, weight and power compared to monostatic LIDAR one, a bistatic LIDAR system has been proposed as a cost-effective solution that can be integrated on small drones for the early detection of crop diseases [ 132 , 133 ]. The extension of this method to the agricultural sector was evaluated to measure CO 2 concentrations associated with photosynthesis and respiration [ 105 , 134 ].…”

Bistatic DIAL for Multi-Species Aviation Pollutant Measurements from RPAS

“…The conceptual design of the bistatic measurement system was initially proposed in [10], based on previous research [11][12][13][14]. As depicted in Fig.…”

“…2 depicts the payload bay of a recent variant of the AEROSONDE RPAS, which will serve as the initial reference for the system components design. In [10] we introduced the key features of the measuring system and discussed the rationale supporting its development. A calibration technique was also introduced, employing a second ground-based LIDAR emitter and electro-optics photo-detectors.…”

“…From Eq. 7, the fraction between the measured incident laser energy associated with the on-absorption line of pollutant species P and the one associated with the off-absorption line, can be expressed as [10]:…”