What is pwv_kpno?

pwv_kpno is a scientific Python package that provides models for the atmospheric transmission due to precipitable water vapor (PWV) at user specified sites. By measuring the delay of dual-band GPS signals traveling through the atmosphere, it is possible to determine the PWV column density along the line of sight. pwv_kpno leverages this principle to provide atmospheric models for user definable sites as a function of date, time, and airmass. Using the package, ground-based photometric observations taken between 3,000 and 12,000 Å can be easily corrected for atmospheric effects due to PWV.

How it Works

The SuomiNet project is a meteorological initiative that provides semi-hourly PWV measurements for hundreds of GPS receivers worldwide. The pwv_kpno package uses published SuomiNet data in conjunction with MODTRAN models to determine the modeled, time-dependent atmospheric transmission. By default, the package provides access to the modeled transmission function at Kitt Peak National Observatory. However, the package is designed to be easily extensible to other locations within the SuomiNet Network. Additionally, pwv_kpno provides access to atmospheric models as a function of PWV, which is independent of geographical location.

Contributing and Attribution	Acknowledgements	Additional Resources
pwv_kpno is open source software released under the GNU General Public License. Issues raised on GitHub and pull requests from contributors are welcome. Additionally, pull requests introducing default configuration files for new sites are also welcome. If you use pwv_kpno as part of any published work or research, we ask that you please cite Perrefort, Wood-Vasey et al. 2018 If the publisher allows, you can also include a footnote with a link pointing to this documentation page.	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. This work was supported in part by the US Department of Energy Office of Science under DE-SC0007914.	1. The official pwv_kpno paper is available on Arxiv.org.
		2. An up time monitor for the SuomiNet web server can be found here.
		3. To learn more about the SuomiNet project, see suominet.ucar.edu.
		4. For an additional example on the correlation between GPS signals and atmospheric modeling, see Blake and Shaw, 2011.