Articles | Volume 18, issue 18
https://doi.org/10.5194/amt-18-4593-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-18-4593-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
18 Sep 2025
Research article |
| 18 Sep 2025
| 18 Sep 2025
JLH Mark2 – An Improved Opto-Mechanical Approach to Open-Path in situ Water Vapor Measurement in the Upper Troposphere/Lower Stratosphere
Robert L. Herman
CORRESPONDING AUTHOR
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Robert F. Troy
Robert Troy Engineering, West Hills, California, 91307, USA
formerly at: Jet Propulsion Laboratory, Pasadena, California, 91109, USA
Kim M. Aaron
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Isabelle Sanders
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Kevin Schwarm
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Joshua Eric Klobas
Aeronautics Systems, Northrop Grumman Systems Corporation, Redondo Beach, California, 90278, USA
Aaron Swanson
Aeronautics Systems, Northrop Grumman Systems Corporation, Redondo Beach, California, 90278, USA
Andrew Carpenter
Aeronautics Systems, Northrop Grumman Systems Corporation, Redondo Beach, California, 90278, USA
Scott Ozog
Aeronautics Systems, Northrop Grumman Systems Corporation, Redondo Beach, California, 90278, USA
Keith Chin
formerly at: Jet Propulsion Laboratory, Pasadena, California, 91109, USA
Lance E. Christensen
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Dejian Fu
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Robert F. Jarnot
Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, 91109, USA
Robert A. Stachnik
formerly at: Jet Propulsion Laboratory, Pasadena, California, 91109, USA
Ramabhadran Vasudev
formerly at: Jet Propulsion Laboratory, Pasadena, California, 91109, USA
Data sets
SEAC4RS ER-2 Aircraft Miscellaneous Data: JLH instrument. R. L. Herman et al. https://doi.org/10.5067/ASDC/SUBORBITAL/SEAC4RS_Miscellaneous_ER2_Data_1
Short summary
This paper presents a new opto-mechanical design for an airborne atmospheric water vapor sensor, the Jet Propulsion Laboratory Laser Hygrometer (JLH) Mark2. The design maximizes instrument optical stability over the wide range of temperatures experienced during flight. We demonstrate that key changes in the redesigned instrument have significantly improved the performance and precision of water vapor measurements. We did this research to enable improved scientific instrumentation for aircraft.
This paper presents a new opto-mechanical design for an airborne atmospheric water vapor sensor,...
