Sunrise

Sunrise is a D-Bus application and standalone library that calculates sunrise and sunset times for automation use.

Usage

D-Bus Service

The following methods are available for D-Bus consumption:

Brightness (Double, Double coordinates) ↦ (Double percentage)
Sunrise (Double, Double coordinates) ↦ (UInt64 time)
Sunset (Double, Double coordinates) ↦ (UInt64 time)

The current D-Bus service name is me.lacour.Sunrise1. Introspection is available.

Standalone Library

sun.cpp and sun.h can be dropped into your project for direct usage. This is useful for microcontroller applications.

Advanced parameters can be used, such as setting a custom zenith angle or day offset.

Example usage:

#include <sun.h>

int main() {
  double lat = 35.535113;
  double lng = -115.451481;

  Sun sun(lat, lng);

  bool rises = sun.rises();
  long sunrise = sun.sunrise();

  bool sets = sun.sets();
  long sunset = sun.sunset();

  double brightness = sun.brightness();

  return 0;
}

Installation

Sunrise is currently only available for direct installation on Arch Linux: https://aur.archlinux.org/packages/sunrise/

Building

The D-Bus development library is required for building from source (libdbus on Arch, libdbus-1-dev on Debian and Ubuntu, and dbus-devel on Fedora).

git clone https://github.com/laCour/sunrise.git
cd sunrise
make

In order to run the binary without connecting to the elevated D-Bus system bus, define DEBUG in main.h.

References

• The Astronomical Almanac from the United States Naval Observatory (USNO)
• NASA Space Science Data Coordinated Archive (NSSDCA)
• Astronomical Applications Department of the U.S. Naval Observatory

Notes

The purpose of this project was to further define constants used in calculating sunset and sunrise times. Previously, the source of constants used in calculations were not defined anywhere these equations were used. Although I have not been able to find the source of all constants, the majority have been defined.

The following constants have not yet been sourced:

• SUN_MEAN_LONGITUDE - Equations use a modified mean longitude (about 0.7% more than the known mean longitude), I've not been able to find how this has been modified.
• 0.06571 - Used to calculate the mean time of rising/setting.
• 6.622 - Used to calculate the mean time of rising/setting.

EARTH_MEAN_ORBITAL_DIFF is a century constant based on the calculated distances of the earth's aphelion and perihelion for the next 100 years.