# poliastro.earth.sensors¶

## Module Contents¶

### Functions¶

 min_and_max_ground_range(h, η_fov, η_center, R) Calculates the minimum and maximum values of ground-range angles ground_range_diff_at_azimuth(h, η_fov, η_center, β, φ_nadir, λ_nadir, R) Calculates the difference in ground-range angles from the η_center angle and the latitude and longitude of the target
poliastro.earth.sensors.min_and_max_ground_range(h, η_fov, η_center, R)

Calculates the minimum and maximum values of ground-range angles

Parameters
• h (Quantity) – Altitude over surface.

• η_fov (Quantity) – Angle of the total area that a sensor can observe.

• η_center (Quantity) – Center boresight angle.

• R (Quantity) – Attractor equatorial radius.

Returns

• Λ_min (~astropy.units.Quantity) – Minimum value of latitude and longitude.

• Λ_max (~astropy.units.Quantity) – Maximum value of latitude and longitude.

Notes

For further information, please take a look at “Fundamentals of Astrodynamics and Applications”, 4th ed (2013)” by David A. Vallado, pages 853-860.

poliastro.earth.sensors.ground_range_diff_at_azimuth(h, η_fov, η_center, β, φ_nadir, λ_nadir, R)

Calculates the difference in ground-range angles from the η_center angle and the latitude and longitude of the target for a desired phase angle, β, used to specify where the sensor is looking.

Parameters
• h (Quantity) – Altitude over surface.

• η_fov (Quantity) – Angle of the total area that a sensor can observe.

• η_center (Quantity) – Center boresight angle.

• β (Quantity) – Azimuth angle, used to specify where the sensor is looking.

• R (Quantity) – Earth equatorial radius.

Returns

• delta_λ (~astropy.units.Quantity) – The difference in ground-range angles from the n_center angle.

• φ_tgt (~astropy.units.Quantity) – Latitude angle of the target point.

• λ_tgt (~astropy.units.Quantity) – Longitude angle of the target point.

Raises

ValueError – This formula always gives the answer for the short way to the target ot the acute angle, β, which must be greater than 0º and less than 180º.

Notes

For further information, please take a look at “Fundamentals of Astrodynamics and Applications”, 4th ed (2013)” by David A. Vallado, pages 853-860.