Formaldehyde Profiler Using Laser Induced Fluorescence Technique

Formaldehyde (HCHO) is a key trace species that is of great interest to atmospheric scientists in NASA and other research institutions. In this SBIR project, we proposed to build an airborne atmospheric formaldehyde (HCHO) profiler implementing a Laser Induced Fluorescence (LIF) technique. This airborne instrument can also be used on the ground for measuring vertical HCHO profiles. To our knowledge, there exists no previous formaldehyde remote sensor that can measure range resolved formaldehyde profile by any technique. The instrument will be able to provide an HCHO profile from an aircraft flying at 20 km altitude to the ground at a 1 km range resolution, and achieve sensitivities better than 70 part-per-trillion-by-volume (pptv) concentration levels at a range of 1 km at nighttime with one second averaging time. In addition, we will explore the feasibility of daytime operation achieving sensitivity of less than 1 part-per-billion-by-volume (ppbv) at a range of 3 km. In Phase I we have built a breadboard formaldehyde profiler instrument and demonstrated the capability of performing highly sensitive nighttime formaldehyde measurements. The outcome of the Phase I work established the feasibility for high sensitivity detection of range resolved HCHO, and provides the design of the prototype sensor.