1. http://oceanservice.noaa.gov/facts/lidar.html
2. https://www.nasa.gov/content/goddard/hubble-goes-high-definition-to-revisit-iconic-pillars-of-creation
3. [Thin-Film Optical Filters];Macleod,2001
4. [Optical Coating Technology];Baumeister,2004
5. Characterizing sub-nanometer narrow bandpass filters using a Cary 400/500;Burt,2011