skylight 1.1 CRAN release

first CRAN release

BlueGreen Labs releases a new package, skylight. The skylight package returns sky illuminance parameters for both the sun and the moon, for a given date/time and location. In addition, ancillary parameters such as sun and moon azimuth and altitude are provided. The code is an almost verbatim transcription of the work by Janiczek and DeYoung (1987), published in the US Naval observatory circular. An online copy of this manuscripts can be found on the internet archive (

How to cite this package in your article

You can cite this package like this “we obtained sky illuminance data using the skylight R package (Hufkens 2022)". Here is the full bibliographic reference to include in your reference list:

Koen Hufkens. (2022). bluegreen-labs/skylight: skylight: A Simple Sky Illuminance Model. Zenodo.

In addition, reference the original work by Janiczek and DeYoung (1987)


To install the current stable release use a CRAN repository:



  • Janiczek and DeYoung (1997). Computer Programs for Sun and Moon Illuminance With Contingent Tables and Diagrams, US Naval observatory circular nr. 171, 1987
Koen Hufkens, PhD
Partner, Researcher

As an earth system scientist and ecologist I model ecosystem processes.