• Skip to primary navigation
  • Skip to main content
SRI logo
  • About
    • Press room
    • Our history
  • Expertise
    • Advanced imaging systems
    • Artificial intelligence
    • Biomedical R&D services
    • Biomedical sciences
    • Computer vision
    • Cyber & formal methods
    • Education and learning
    • Innovation strategy and policy
    • National security
    • Ocean & space
    • Quantum
    • Robotics, sensors & devices
    • Speech & natural language
    • Video test & measurement
  • Ventures
  • NSIC
  • Careers
  • Contact
  • 日本支社
Search
Close
Oceans & space publications October 1, 2008

Comparison of Water Vapor Measurements By Airborne Sun Photometer and Diode Laser Hygrometeron the NASA DC-8

Abstract

In January–February 2003, the 14-channel NASA Ames airborne tracking sun photometer (AATS) and the NASA Langley/Ames diode laser hygrometer (DLH) were flown on the NASA DC-8 aircraft. The AATS measured column water vapor on the aircraft-to-sun path, while the DLH measured local water vapor in the free stream between the aircraft fuselage and an outboard engine cowling. The AATS and DLH measurements have been compared for two DC-8 vertical profiles by differentiating the AATS column measurement and/or integrating the DLH local measurement over the altitude range of each profile (7.7–10 km and 1.1–12.5 km). These comparisons extend, for the first time, tests of AATS water vapor retrievals to altitudes >∼6 km and column contents <0.1 g cm−2. To the authors’ knowledge, this is the first time suborbital spectroscopic water vapor measurements using the 940-nm band have been tested in conditions so high and dry. Values of layer water vapor (LWV) calculated from the AATS and DLH measurements are highly correlated for each profile. The composite dataset yields r 2 0.998, rms difference 7.7%, and bias (AATS minus DLH) 1.0%. For water vapor densities AATS and DLH had r 2 0.968, rms difference 27.6%, and bias (AATS minus DLH) −4.2%. These results for water vapor density compare favorably with previous comparisons of AATS water vapor to in situ results for altitudes <∼6 km, columns ∼0.1 to 5 g cm−2, and densities ∼0.1 to 17 g m−3.

↓ View online

Share this
Career call to action image

Work with us

Search jobs

How can we help?

Once you hit send…

We’ll match your inquiry to the person who can best help you.

Expect a response within 48 hours.

Our work

Case studies

Publications

Timeline of innovation

Areas of expertise

Institute

Leadership

Press room

Media inquiries

Compliance

Careers

Job listings

Contact

SRI Ventures

Our locations

Headquarters

333 Ravenswood Ave
Menlo Park, CA 94025 USA

+1 (650) 859-2000

Subscribe to our newsletter


日本支社
SRI International
  • Contact us
  • Privacy Policy
  • Cookies
  • DMCA
  • Copyright © 2023 SRI International
Manage Cookie Consent
To provide the best experiences, we use technologies like cookies to store and/or access device information. Consenting to these technologies will allow us to process data such as browsing behavior or unique IDs on this site. Not consenting or withdrawing consent, may adversely affect certain features and functions.
Functional Always active
The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network.
Preferences
The technical storage or access is necessary for the legitimate purpose of storing preferences that are not requested by the subscriber or user.
Statistics
The technical storage or access that is used exclusively for statistical purposes. The technical storage or access that is used exclusively for anonymous statistical purposes. Without a subpoena, voluntary compliance on the part of your Internet Service Provider, or additional records from a third party, information stored or retrieved for this purpose alone cannot usually be used to identify you.
Marketing
The technical storage or access is required to create user profiles to send advertising, or to track the user on a website or across several websites for similar marketing purposes.
Manage options Manage services Manage {vendor_count} vendors Read more about these purposes
View preferences
{title} {title} {title}