Feasibility Study for an Airborne N₂O Lidar

Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt (DLR) D-82234 Oberpfaffenhofen, Germany Lead Author e-mail address: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 9 April 2026

Abstract

Nitrous oxide, N₂O is the third most important anthropogenic greenhouse gas after carbon dioxide and methane. The major source is nitrogen fertilization in croplands. Differential absorption lidar is very demanding since suitable absorption lines exist only in the infrared, which challenges lidar transmitter and detector options. Spectroscopic investigations and lidar instrumental noise simulations show that in the 4.5 µm band a trough position between two strong N₂O lines is likely the best option for an airborne lidar. A second option exists in the 3.9 µm band, at the cost of higher laser frequency stability constraints. Independently on the 3.9 versus 4.5 µm question an airborne lidar is expected to fulfill the N₂O measurement requirements for regional gradient or hot spot detection with technically realizable and affordable transmitter (100 mW average laser power) and receiver (20 cm telescope) characteristics. However, such a system would benefit from progress in infrared transmitter and detector technology.