Overview

pwv_kpno is a Python package for modeling the atmospheric absorption due to H₂O at Kitt Peak National Observatory. It provides atmospheric models from 300 to 1,200 nm for years 2010 onward. Understanding atmospheric effects is important when calibrating ground based astronomical observations. Astronomers traditionally calibrate broad-band imaging by using a reference catalog to compute correction terms for color, airmass, and perhaps a higher-order color-airmass term. pwv_kpno provides an alternative that can be performed at the user’s convenience.

Atmospheric absorption in the near-infrared is highly dependent on the column density of precipitable water vapor (PWV). By measuring the delay of GPS signals through the atmosphere, the SuomiNet project provides accurate PWV measurements for multiple, international locations. The pwv_kpno package uses published SuomiNet data in conjunction with MODTRAN models to determine the modeled atmospheric transmission function at Kitt Peak in close to real time. The package also provides automated retrieval and processing of SuomiNet data, allowing photometry to typically be corrected within an hour of observation.

pwv_kpno is open source software released under the GNU General Public License. Issues raised on GitHub and pull requests from contributors are welcome.

How to Cite

If you use pwv_kpno as part of any published work or research, we ask that you please use the following standard acknowledgement:

This research made use of the pwv_kpno python package, an open source project that provides models for the atmospheric absorption due to precipitable water vapor in the near-infrared (Perrefort, Wood-Vasey et al. 2018)

If the publisher allows, you can also include a footnote with a link pointing to the documentation page https://mwvgroup.github.io/pwv_kpno/.

Acknowledgements

This work is based in part on observations taken at Kitt Peak National Observatory, National Optical Astronomy Observatory (NOAO Prop. IDs: 2011B-0482 and 2012B-0500; PI: Wood-Vasey), which is operated by the Association of Universities for Research in Astronomy (AURA) under a cooperative agreement with the National Science Foundation.

Additional Resources

• An up time monitor for the SuomiNet website can be found here.
• For more information on the Kitt Peak National Observatory, see www.noao.edu/kpno/
• To learn more about the SuomiNet project, see www.suominet.ucar.edu/overview.html.
• For an additional example on the correlation between GPS signals and atmospheric modeling, see Blake and Shaw, 2011.