The Daily Press has published a story covering a very interesting subject: NASA Langley Research Center testing out the world’s first triple-pulsed laser system in a King Air B200. The Triple-pulsed LIDAR remote sensing system’s mission is to measure carbon dioxide and water vapor. The tests carried two pilots and two scientists who flew from Hampton to New Jersey and then to North Carolina.
“These are the two very dominant greenhouse gases,” principal investigator Upendra N. Singh told the Daily Press. “So that will allow you to understand how the greenhouse gases are rising up and how much effect it can have on the atmosphere or the temperature of this planet.”
NASA Langley is well known for their LIDAR development in order to measure CO2, and often times have incorporated King Air to carry the instrumentation (along with a C-130H). The new system is certainly one of the most complicated, which required the project manager Mulugeta Petros and his team to determine a way to shoot three distinct pulses, each a different color/wavelength, within 200 microseconds, all during flight.
“It’s very difficult,” Petros told the Daily Press. “We had to push the technology. Basically, that’s what NASA does — it pushes the technology.”
“In the beginning,” said Singh, “we thought we can never build it. But NASA was OK because the concept was so unique that, if you could build it, the payoff is quite large.”
The Daily Press gave the following breakdown of the process:
“A LIDAR instrument shoots laser pulses through a column of air, where they hit their target and bounce back to the plane.
The new instrument needs three pulses to take two measurements because the third acts as a neutral reference wavelength, while the other two are designed to have some of their energy absorbed by either CO2 or water vapor molecules, which reduces their return time.
Climate scientists are always looking for ways to better understand the sources and impacts of carbon dioxide in the atmosphere. But a LIDAR that can also measure water vapor isn’t just about studying the greenhouse effects; it’s also about understanding, and thus better predicting, the impacts on weather.”
“Earth is a water planet,” said NASA Langley atmospheric scientist Tamer F. Refaat. “Only about 0.04 percent of water is in the atmosphere; although it’s very little, it’s very dynamic. Most of the weather phenomena that you see — winds, rain, fog, hurricanes, all this — is coming because of that little amount of water vapor in the atmosphere.”
The ultimate end goal is to produce a more compact model of the system that can be sent to space. The team noted it will allow for measurements day and night and produce a much better picture of CO2 conditions by allowing the additional measurement of polar regions. When that happens, it will be nice knowing the King Air played such a vital a part in that mission.