The following video shows LGR's Ultraportable Greenhouse Gas Analyzer recording methane (as well as CO2 and H2O) from aircraft to determine the location of natural gas leaks while flying above pipelines.
http://fox40.com/2012/11/27/detecting-natural-gas-leaks/
http://www.pgecurrents.com/2012/11/27/pge-uc-davis-research-new-aerial-gas-leak-survey-technology/
http://www.news.ucdavis.edu/search/news_detail.lasso?id=10408
http://www.sfgate.com/business/article/Methane-detector-tracks-pipeline-leaks-4071523.php
http://www.capradio.org/articles/2012/11/27/new-technology-helps-detect-gas-leaks-from-the-skies
http://www.youtube.com/watch?v=kbLqBijqac8
http://yubanet.com/california/Pollution-detecting-aircraft-surveys-PG-E-pipeline-for-gas-leaks.php#.ULVfOtPjnqE
http://www.dailydemocrat.com/news/ci_22076099/ud-davis-pollution-detecting-aircraft-surveys-pg-e