Remote sensing of motor vehicle exhaust emissions: the road ahead

摘要

In the past decade interest has focused on the remote analysis of emissions from motor vehicles using spectrometric techniques, driven by recognition of the fact that a very large proportion of the environemtnal damage done in this way originates with a small percentage of vheicles. Several instrumentation manufacturers now market such devices, and others are developing new technologies that will offer opportunities for enhanced performance and lower cost. In this paper we review the evolution of technologies and methodologies applied to motor vehicle exhaust emissions, ranging from simple broadband sources and band-pass filters o tunable diode laser absorption spectroscopy. In so doing we examine the compromises and sources of error inhernet in each which have earned such devices a very variable reputation, at least in the early years of development. we also look at techniques that may have the potential to solve these problems, and critically examine the reasons why tese have not (yet) been applied. In conclusion, we will present initial findings and resutls from a European consortium studying the problems of cost-effective emissions monitoring, and validation of emissions inventory data using complementary numerical modelling techniques.