Observer

class pysolorie.observer.Observer(observer_latitude: float | None = None, observer_longitude: float | None = None)

A class to model an observer based on horizontal and equatorial pictures of the sun-earth geometry.

To instantiate the Observer class, provide the following parameter.

Parameters:

• observer_latitude (Optional[float]) – The latitude of the observer in degrees (optional).

• observer_longitude (Optional[float]) – The longitude of the observer in degrees (optional).

calculate_sunrise_sunset(day_of_year: int) → tuple

Calculate the hour angle at sunrise and sunset.

The hour angle at sunrise and sunset is calculated using the formula:

\[\cos(\omega) = -\tan(\phi) \times \tan(\delta)\]

- \(\omega\) is the hour angle

- \(\phi\) is the latitude of the observer

- \(\delta\) is the solar declination.

Parameters:

day_of_year (int) – The day of the year.

Returns:

The hour angle at sunrise and sunset in radians.

Return type:

tuple

calculate_zenith_angle(day_of_year: int, solar_time: float) → float

Calculate the solar zenith angle.

The solar zenith angle is calculated using the formula:

\[\cos(\theta_z) = \sin(\phi) \times \sin(\delta) + \cos(\phi) \times \cos(\delta) \times \cos(\omega)\]

- \(\theta_z\) is the solar zenith angle

- \(\phi\) is the latitude of the observer

- \(\delta\) is the solar declination

- \(\omega\) is the hour angle.

Parameters:

• day_of_year (int) – The day of the year.

• solar_time (float) – The solar time in seconds.

Returns:

The zenith angle in radians.

Return type:

float

property observer_latitude: float | None

Getter for the observer’s latitude.

Returns:

The observer’s latitude in radians.

Return type:

Optional[float]

property observer_longitude: float | None

Getter for the observer’s longitude.

Returns:

The observer’s longitude in radians.

Return type:

Optional[float]