# Class ElevationAngle

Object
Angle
ElevationAngle

All Implemented Interfaces:
  `Serializable`, `Comparable<Angle>`, `Formattable`

public final class ElevationAngle extends Angle
The angular height of an object measured from the horizontal plane. The elevation angle is part of local topocentric coordinates together with azimuth and distance. For visible objects the elevation is an angle between 0° and 90°.
Note: Elevation angle and altitude angle may be used interchangeably. Both altitude and elevation words are also used to describe the height in meters above sea level.

## Immutability and thread safety

This final class is immutable and thus inherently thread-safe.

Since:
  0.4
See Also:
  - `CoordinateSystems​.angle(AxisDirection, AxisDirection)`
  - Serialized Form

- ## Field Summary

  Fields
  Modifier and Type
  Field
  Description
  `static final ElevationAngle`
  `NADIR`
  An elevation angle of -90° for an imaginary point directly below a location.
  `static final ElevationAngle`
  `ZENITH`
  An elevation angle of 90° for an imaginary point directly above a location.

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `ElevationAngle(double ε)`
  Constructs a new elevation angle with the specified angular value.
  `ElevationAngle(String string)`
  Constructs a newly allocated `ElevationAngle` object that contain the angular value represented by the string.

- ## Method Summary

  ### Methods inherited from class Angle

  `compareTo, degrees, equals, formatTo, hashCode, radians, toString`

  ### Methods inherited from class Object

  `clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Field Details

  - ### ZENITH

    public static final ElevationAngle ZENITH
    An elevation angle of 90° for an imaginary point directly above a location. This is the opposite of `NADIR` direction.

  - ### NADIR

    public static final ElevationAngle NADIR
    An elevation angle of -90° for an imaginary point directly below a location. This is the opposite of `ZENITH` direction.

- ## Constructor Details

  - ### ElevationAngle

    public ElevationAngle(double ε)
    Constructs a new elevation angle with the specified angular value.
    Parameters:
      `ε` - elevation angle value in decimal degrees.

  - ### ElevationAngle

    public ElevationAngle(String string) throws NumberFormatException
    Constructs a newly allocated `ElevationAngle` object that contain the angular value represented by the string. The string should represent an angle in either fractional degrees (e.g. 45.5°) or degrees with minutes and seconds (e.g. 45°30').
    Parameters:
      `string` - a string to be converted to an `ElevationAngle`.
    Throws:
      `NumberFormatException` - if the string does not contain a parsable angle, or represents an elevation angle.