s2d2.orbit_tools

Module Contents

Functions

wgs84_param()
earth_eccentricity()
earth_axes()
standard_gravity()	provide value for the standard gravitational parameter of the Earth
transform_rpy_xyz2ocs(xyz, uvw, roll, pitch, yaw, ...)
estimate_inclination_via_xyz_uvw(xyz, uvw)
calculate_correct_mapping(Zn_grd, Az_grd, bnd, det, ...)	param Zn_grd: observation angles of the different detectors/bands
remap_observation_angles(Ltime, lat, lon, radius, ...)
get_absolute_timing(lat, lon, sat_dict)
acquisition_angles(Px, Gx)	given satellite and ground coordinates, estimate observation angles
line_of_sight(Lat, Lon, Zn, Az[, eccentricity, major_axis])	param Lat: location of observation angles
ground_vec(Lat, Lon[, eccentricity, major_axis])	get ground coordinates in Cartesian system
_make_timing_system(IN, dX, dY, Ltime)
time_fitting(Ltime, Az, Zn, bnd, det, X, Y, geoTransform)
orbital_fitting(Sat, Gx[, lat, lon, radius, ...])	param Sat: observation vector from ground location towards the satellite
_omega_lon_calculation(φ, λ, inclination)	param lat: location on the Earth
_gc_calculation(ltime, period, inclination, ω_0, λ_0)
orbital_calculation(ltime, radius, inclination, ...)
observation_calculation(ltime, Sat, Gx, radius, ...)	param ltime:
_pert_param(idx, pert, *args)	perterp one of the arguments
partial_obs(ltime, Sat, Gx, φ, λ, radius, inclination, ...)	numerical differentiation, via pertubation of the observation vector
partial_tim(ltime, Sat, Gx, φ, λ, radius, inclination, ...)

s2d2.orbit_tools.wgs84_param()

s2d2.orbit_tools.earth_eccentricity()

s2d2.orbit_tools.earth_axes()

s2d2.orbit_tools.standard_gravity()

provide value for the standard gravitational parameter of the Earth

Returns:

μ – standard gravity

Return type:

float, unit: m**3 * s**-2

s2d2.orbit_tools.transform_rpy_xyz2ocs(xyz, uvw, roll, pitch, yaw, xyz_time, ang_time)

s2d2.orbit_tools.estimate_inclination_via_xyz_uvw(xyz, uvw)

s2d2.orbit_tools.calculate_correct_mapping(Zn_grd, Az_grd, bnd, det, grdTransform, crs, sat_dict=None)

Parameters:

• Zn_grd ({numpy.ndarray, numpy.masked.array}, size=(k,l,h)) – observation angles of the different detectors/bands

• Az_grd ({numpy.ndarray, numpy.masked.array}, size=(k,l,h)) – observation angles of the different detectors/bands

• bnd (numpy.ndarray, size=(h,)) – number of the band, corresponding to the third dimension of ‘Zn_grd’

• det (numpy.ndarray, size=(h,)) – number of the detector, corresponding to the third dimension of ‘Zn_grd’

• grdTransform (tuple, size=(8,)) – geotransform of the grid of ‘Zn_grd’ and ‘Az_grd’

• crs (osgeo.osr.SpatialReference() object) – coordinate reference system (CRS)

• sat_dict (dictonary) –

  metadata of the satellite platform, preferably having the following elements:

  • ’inclination’

  • ’revolutions_per_day’

  • ’altitude’

Returns:

• Ltime (numpy.ndarray, size=(p,), unit=seconds) – asd

• lat, lon (float, unit=degrees) – ground location of the satelite at time 0

• radius (float, unit=metre) – distance away from Earths’ center

• inclination (unit=degrees) – tilt of the orbital plane in relation to the equator

• period (float, unit=seconds) – time it takes to complete one revolution

• time_para (numpy.ndarray, size=(p,b)) – polynomial fitting parameters for the different bands (b)

• combos (numpy.ndarray, size=(h,2)) – combinations of band and detector pairs, corresponding to the third dimension of ‘Zn_grd’

s2d2.orbit_tools.remap_observation_angles(Ltime, lat, lon, radius, inclination, period, time_para, combos, X_grd, Y_grd, det_stack, bnd_list, geoTransform, crs)

s2d2.orbit_tools.get_absolute_timing(lat, lon, sat_dict)

s2d2.orbit_tools.acquisition_angles(Px, Gx)

given satellite and ground coordinates, estimate observation angles

s2d2.orbit_tools.line_of_sight(Lat, Lon, Zn, Az, eccentricity=None, major_axis=None)

Parameters:

• Lat (numpy.ndarray, size=(m,n), unit=degrees) – location of observation angles

• Lon (numpy.ndarray, size=(m,n), unit=degrees) – location of observation angles

• Zn (numpy.ndarray, size=(m,n), unit=degrees) – polar angles of line of sight to the satellite, also known as, delcination and right ascension.

• Az (numpy.ndarray, size=(m,n), unit=degrees) – polar angles of line of sight to the satellite, also known as, delcination and right ascension.

• eccentricity (float) – eccentricity squared, if None default is WGS84 (6.69E-10)

• major_axis (float, unit=meters) – length of the major axis, if None default is WGS84 (6.37E6)

Returns:

• Sat (numpy.ndarray, size=(m*n,3)) – observation vector from ground location towards the satellite

• Gx (numpy.ndarray, size=(m*n,3)) – ground location in Cartesian coordinates

s2d2.orbit_tools.ground_vec(Lat, Lon, eccentricity=None, major_axis=None)

get ground coordinates in Cartesian system

Parameters:

• Lat (numpy.ndarray, size=(m,n), unit=degrees) – location of observation angles

• Lon (numpy.ndarray, size=(m,n), unit=degrees) – location of observation angles

• eccentricity (float) – eccentricity squared, if None default is WGS84 (6.69E-10)

• major_axis (float, unit=meters) – length of the major axis, if None default is WGS84 (6.37E6)

Returns:

Gx – ground location in Cartesian coordinates

Return type:

numpy.ndarray, size=(m*n,3)

s2d2.orbit_tools._make_timing_system(IN, dX, dY, Ltime)

s2d2.orbit_tools.time_fitting(Ltime, Az, Zn, bnd, det, X, Y, geoTransform)

s2d2.orbit_tools.orbital_fitting(Sat, Gx, lat=None, lon=None, radius=None, inclination=None, period=None, sat_dict=None, convtol=0.001, orbtol=1.0, maxiter=20, printing=False)

Parameters:

• Sat (numpy.ndarray, size=(m*n,3)) – observation vector from ground location towards the satellite

• Gx (numpy.ndarray, size=(m*n,3)) – ground location in Cartesian coordinates

• lat (float, unit=degrees) – location of satellite within orbital track

• lon (float, unit=degrees) – location of satellite within orbital track

• radius (float, unit=meter) – radius towards the orbiting satellite

• inclination (float, unit=degrees, range=-180...+180) – inclination of the orbital plane with the equator

• period (float, unit=seconds) – time it takes to revolve one time around the Earth

• sat_dict (dictonary) –

s2d2.orbit_tools._omega_lon_calculation(φ, λ, inclination)

Parameters:

• lat ({float, numpy.array}, unit=radians) – location on the Earth

• lon ({float, numpy.array}, unit=radians) – location on the Earth

• inclination ({float, numpy.array}, unit=radians) – angle of the orbital plane i.r.t. the equator

s2d2.orbit_tools._gc_calculation(ltime, period, inclination, ω_0, λ_0)

s2d2.orbit_tools.orbital_calculation(ltime, radius, inclination, period, ω_0, λ_0)

s2d2.orbit_tools.observation_calculation(ltime, Sat, Gx, radius, inclination, period, ω_0, λ_0)

Parameters:

• ltime (numpy.array, size=(m,1)) –

• Sat (numpy.ndarray, size=(m,3)) – observation vector from ground location towards the satellite

• Gx (numpy.ndarray, size=(m,3)) – ground location in Cartesian coordinates

• radius (float, unit=meter) – radius towards the orbiting satellite

• inclination (float, unit=degrees, range=-180...+180) – inclination of the orbital plane with the equator

• period (float, unit=seconds) – time it takes to revolve one time around the Earth

• ω_0 (float, unit=degrees) – angle towards ascending node, one of the orbit Euler angles

• λ_0 (float, unit=degrees) – ephemeris longitude

Returns:

Vx

Return type:

numpy.array, size=(m,3)

s2d2.orbit_tools._pert_param(idx, pert, *args)

perterp one of the arguments

Parameters:

• idx (integer, range=0...m-1) – index which of the arguments should be perturbed

• pert ({float, numpy.array}) – amount of pertubation

• args (tuple, size=m) – tuple with different arguments, with datatypes like arrays or floats

Returns:

args – tuple with different arguments, with datatypes like arrays or floats

Return type:

tuple, size=m

s2d2.orbit_tools.partial_obs(ltime, Sat, Gx, φ, λ, radius, inclination, period)

numerical differentiation, via pertubation of the observation vector

s2d2.orbit_tools.partial_tim(ltime, Sat, Gx, φ, λ, radius, inclination, period, pertubation=0.1)