Precision Doppler Shift Measurements with a Frequency Comb Calibrated Laser Heterodyne Radiometer
-
1.
National Institute of Standards and Technology
-
2.
University of Colorado Boulder
-
3.
California Institute of Technology
Abstract
We report precision atmospheric spectroscopy of CO2 using a laser heterodyne radiometer (LHR) calibrated with an optical frequency comb. Using the comb-calibrated LHR, we record spectra of atmospheric CO2 near 1572.33 nm with a spectral resolution of 200 MHz using sunlight as a light source. The measured CO2 spectra exhibit frequency shifts by approximately 11 MHz over the course of the five-hour measurement, and we show that these shifts are caused by Doppler effects due to wind along the spectrometer line of sight. The measured frequency shifts are in excellent agreement with an atmospheric model, and we show that our measurements track the wind-induced Doppler shifts with a relative frequency precision of 100 kHz (15 cm/s), equivalent to a fractional precision of a few parts in 1010. These results demonstrate that frequency-comb-calibrated LHR enables precision velocimetry that can be of use in applications ranging from climate science to astronomy.
Acknowledgement
R.C. acknowledges support from the National Academies NRC Research Associateship Program. The authors thank Eugene Tsao and David Plusquellic for valuable comments and discussions. This work is a contribution of NIST and is not subject to copyright in the USA. Mention of specific products or trade names is for technical and scientific information and does not constitute an endorsement by NIST.
Funding
This work was supported by the NIST IMS program, NIST financial assistance award 70NANB18H006, and the NASA Astrophysics Division. R.C. acknowledges support from the National Academies NRC Research Associateship Program.
Acknowledgement
The authors thank Eugene Tsao and David Plusquellic for valuable comments and discussions. This work is a contribution of NIST and is not subject to copyright in the United States. Mention of specific products or trade names is for technical and scientific information and does not constitute an endorsement by NIST.
Files
| Name | Size | Download all |
|---|---|---|
|
md5:95d48ff4df69c378814509b13482d993
|
638.6 kB | Preview Download |
Additional details
- National Institute of Standards and Technology
- 70NANB18H006
- National Aeronautics and Space Administration
- 80NSSC21K2006
- Submitted
-
2023-07-14Submitted v1
- Submitted
-
2023-07-13Compiled
- Caltech groups
- Division of Geological and Planetary Sciences
- Publication Status
- Submitted