Ellipsoid

Ellipsoid is meant to capture common geometry functions that are performed on an ellipsoid.

Factory

from isce3.core import ellipsoid

obj = ellipsoid(**kwds)

Documentation

class isce3.core.Ellipsoid.Ellipsoid

Wrapper for pyEllipsoid.

a

Semi-major axis of ellipsoid.

Returns

Semi-major axis of ellipsoid in meters.

Return type

float

b

Semi-minor axis of ellipsoid.

Returns

Semi-minor axis of ellipsoid in meters.

Return type

float

static bind(pyEllipsoid elp)

Binds the current pyEllipsoid instance to another C++ Ellipsoid pointer.

Parameters

elp (pyEllipsoid) – Source of C++ Ellipsoid pointer.

copyFrom(elp)

Copy ellipsoid parameters with any class that has semi-major axis and eccentricity parameters.

Parameters

elp (obj) – Any object that has attributes a and e2.

Returns

None

e2

Eccentricity-squared of ellipsoid.

Returns

Eccentricity-squared of ellipsoid.

Return type

float

getImagingAnglesAtPlatform(pos, vel, los)

Compute azimuth angle and look angle at imaging platform.

Parameters
  • pos (numpy.ndarray) – triplet of floats representing platform position in ECEF coordinates (m)

  • vel (numpy.ndarray) – triplet of floats representing platform veloctity in ECEF coodinates (m/s)

  • los (numpy.ndarray) – triplet of floats representing line-of-sight vector in ECEF coordiantes (m)

Returns

tuple containing:
  • azi (float): Azimuth angle in radians. Measured anti-clockwise from North.

  • look (float): Look angle in radians. Measured w.r.t ellipsoid normal at platform.

Return type

(tuple)

lonLatToXyz(llh)

Transform Lon/Lat/Hgt position to ECEF xyz coordinates.

Parameters

llh (numpy.ndarray) – triplet of floats representing Lon (rad), Lat (rad) and hgt (m). Can be of shape (3,) or (n,3).

Returns

triplet of floats representing ECEF coordinates in meters

Return type

numpy.ndarray

rDir(lat, hdg)

Directional radius as a function of heading and latitude.

Note

lat and hdg should be of same size.

Parameters
  • lat (float or numpy.ndarray) – Latitude in radians. Can be constant or 1D array.

  • hdg (float or numpy.ndarray) – Heading in radians. Measured clockwise from North.

Returns

Directional radius in meters.

Return type

float or numpy.ndarray

rEast(lat)

Prime Vertical Radius as a function of latitude.

Parameters

lat (float or numpy.ndarray) – Latitude in radians. Can be constant or 1D array.

Returns

Prime Vertical radius in meters

Return type

float or numpy.ndarray

rNorth(lat)

Meridional radius as a function of latitude.

Parameters

lat (float or numpy.ndarray) – Latitude in radians. Can be constant or 1D array.

Returns

Meridional radius in meters

Return type

float or numpy.ndarray

xyzToLonLat(xyz)

Transform Lon/Lat/Hgt position to ECEF xyz coordinates.

Parameters

xyz (numpy.ndarray) – triplet of floats representing ECEF coordinates in meters. Can be of shape (3,) or (n,3).

Returns

triplet of floats representing Lon (rad), Lat (rad) and hgt (m)

Return type

numpy.ndarray