eci: astropy optional, but with substantial error tolerance

v2.4.1

Author: scivision

setup.cfg

@@ -1,6 +1,6 @@
 [metadata]
 name = pymap3d
-version = 2.4.0
+version = 2.4.1
 author = Michael Hirsch, Ph.D.
 author_email = [email protected]
 description = pure Python (no prereqs) coordinate conversions, following convention of several popular Matlab routines.

src/pymap3d/__init__.py

@@ -36,7 +36,7 @@
 from .enu import enu2geodetic, geodetic2enu, aer2enu, enu2aer
 from .ned import ned2ecef, ned2geodetic, geodetic2ned, ecef2nedv, ned2aer, aer2ned, ecef2ned
 from .ecef import geodetic2ecef, ecef2geodetic, eci2geodetic, geodetic2eci, ecef2enuv, enu2ecef, ecef2enu, enu2uvw, uvw2enu
-from .sidereal import datetime2sidereal
+from .sidereal import datetime2sidereal, greenwichsrt
 from .latitude import (
     geod2geoc,
     geoc2geod,
@@ -66,9 +66,9 @@
 from .lox import meridian_arc, meridian_dist, loxodrome_inverse, loxodrome_direct, departure, meanm
 from .los import lookAtSpheroid
 from .timeconv import str2dt
+from .eci import eci2ecef, ecef2eci
 
 try:
     from .azelradec import radec2azel, azel2radec
-    from .eci import eci2ecef, ecef2eci
 except ImportError:
     from .vallado import radec2azel, azel2radec

src/pymap3d/aer.py

@@ -6,10 +6,8 @@
 from .enu import geodetic2enu, aer2enu, enu2aer
 from .ellipsoid import Ellipsoid
 
-try:
-    from .eci import eci2ecef, ecef2eci
-except ImportError:
-    eci2ecef = ecef2eci = None
+from .eci import eci2ecef, ecef2eci
+
 
 __all__ = ["aer2ecef", "ecef2aer", "geodetic2aer", "aer2geodetic", "eci2aer", "aer2eci"]
 
@@ -165,7 +163,16 @@ def aer2geodetic(
 
 
 def eci2aer(
-    x: "ndarray", y: "ndarray", z: "ndarray", lat0: "ndarray", lon0: "ndarray", h0: "ndarray", t: datetime
+    x: "ndarray",
+    y: "ndarray",
+    z: "ndarray",
+    lat0: "ndarray",
+    lon0: "ndarray",
+    h0: "ndarray",
+    t: datetime,
+    *,
+    deg: bool = True,
+    use_astropy: bool = True
 ) -> typing.Tuple["ndarray", "ndarray", "ndarray"]:
     """
     takes Earth Centered Inertial x,y,z ECI coordinates of point and gives az, el, slant range from Observer
@@ -187,6 +194,10 @@ def eci2aer(
          observer altitude above geodetic ellipsoid (meters)
     t : datetime.datetime
         Observation time
+    deg : bool, optional
+        true: degrees, false: radians
+    use_astropy: bool, optional
+        use Astropy (recommended)
 
     Returns
     -------
@@ -197,12 +208,10 @@ def eci2aer(
     srange : "ndarray"
          slant range [meters]
     """
-    if eci2ecef is None:
-        raise ImportError("pip install astropy")
 
-    xecef, yecef, zecef = eci2ecef(x, y, z, t)
+    xecef, yecef, zecef = eci2ecef(x, y, z, t, use_astropy=use_astropy)
 
-    return ecef2aer(xecef, yecef, zecef, lat0, lon0, h0)
+    return ecef2aer(xecef, yecef, zecef, lat0, lon0, h0, deg=deg)
 
 
 def aer2eci(
@@ -214,7 +223,9 @@ def aer2eci(
     h0: "ndarray",
     t: datetime,
     ell=None,
+    *,
     deg: bool = True,
+    use_astropy: bool = True
 ) -> typing.Tuple["ndarray", "ndarray", "ndarray"]:
     """
     gives ECI of a point from an observer at az, el, slant range
@@ -239,6 +250,8 @@ def aer2eci(
           reference ellipsoid
     deg : bool, optional
           degrees input/output  (False: radians in/out)
+    use_astropy : bool, optional
+        use AstroPy (recommended)
 
     Returns
     -------
@@ -252,12 +265,9 @@ def aer2eci(
     z : "ndarray"
         ECEF z coordinate (meters)
     """
-    if ecef2eci is None:
-        raise ImportError("pip install numpy")
-
-    x, y, z = aer2ecef(az, el, srange, lat0, lon0, h0, ell, deg)
+    x, y, z = aer2ecef(az, el, srange, lat0, lon0, h0, ell, deg=deg)
 
-    return ecef2eci(x, y, z, t)
+    return ecef2eci(x, y, z, t, use_astropy=use_astropy)
 
 
 def aer2ecef(

src/pymap3d/azelradec.py

@@ -20,7 +20,7 @@
 
 
 def azel2radec(
-    az_deg: "ndarray", el_deg: "ndarray", lat_deg: "ndarray", lon_deg: "ndarray", time: datetime, usevallado: bool = False
+    az_deg: "ndarray", el_deg: "ndarray", lat_deg: "ndarray", lon_deg: "ndarray", time: datetime, *, use_astropy: bool = True
 ) -> typing.Tuple["ndarray", "ndarray"]:
     """
     viewing angle (az, el) to sky coordinates (ra, dec)
@@ -37,8 +37,8 @@ def azel2radec(
               observer longitude [-180, 180] (degrees)
     time : datetime.datetime or str
            time of observation
-    usevallado : bool, optional
-                 default use astropy. If true, use Vallado algorithm
+    use_astropy : bool, optional
+                 default use astropy.
 
     Returns
     -------
@@ -48,20 +48,21 @@ def azel2radec(
          ecliptic declination (degrees)
     """
 
-    if usevallado or Time is None:  # non-AstroPy method, less accurate
-        return vazel2radec(az_deg, el_deg, lat_deg, lon_deg, time)
+    if use_astropy and Time is not None:
 
-    obs = EarthLocation(lat=lat_deg * u.deg, lon=lon_deg * u.deg)
+        obs = EarthLocation(lat=lat_deg * u.deg, lon=lon_deg * u.deg)
 
-    direc = AltAz(location=obs, obstime=Time(str2dt(time)), az=az_deg * u.deg, alt=el_deg * u.deg)
+        direc = AltAz(location=obs, obstime=Time(str2dt(time)), az=az_deg * u.deg, alt=el_deg * u.deg)
 
-    sky = SkyCoord(direc.transform_to(ICRS()))
+        sky = SkyCoord(direc.transform_to(ICRS()))
 
-    return sky.ra.deg, sky.dec.deg
+        return sky.ra.deg, sky.dec.deg
+
+    return vazel2radec(az_deg, el_deg, lat_deg, lon_deg, time)
 
 
 def radec2azel(
-    ra_deg: "ndarray", dec_deg: "ndarray", lat_deg: "ndarray", lon_deg: "ndarray", time: datetime, usevallado: bool = False
+    ra_deg: "ndarray", dec_deg: "ndarray", lat_deg: "ndarray", lon_deg: "ndarray", time: datetime, *, use_astropy: bool = False
 ) -> typing.Tuple["ndarray", "ndarray"]:
     """
     sky coordinates (ra, dec) to viewing angle (az, el)
@@ -78,8 +79,8 @@ def radec2azel(
               observer longitude [-180, 180] (degrees)
     time : datetime.datetime or str
            time of observation
-    usevallado : bool, optional
-                 default use astropy. If true, use Vallado algorithm
+    use_astropy : bool, optional
+                 default use astropy.
 
     Returns
     -------
@@ -89,13 +90,11 @@ def radec2azel(
              elevation [degrees above horizon (neglecting aberration)]
     """
 
-    if usevallado or Time is None:
-        return vradec2azel(ra_deg, dec_deg, lat_deg, lon_deg, time)
-
-    obs = EarthLocation(lat=lat_deg * u.deg, lon=lon_deg * u.deg)
-
-    points = SkyCoord(Angle(ra_deg, unit=u.deg), Angle(dec_deg, unit=u.deg), equinox="J2000.0")
+    if use_astropy and Time is not None:
+        obs = EarthLocation(lat=lat_deg * u.deg, lon=lon_deg * u.deg)
+        points = SkyCoord(Angle(ra_deg, unit=u.deg), Angle(dec_deg, unit=u.deg), equinox="J2000.0")
+        altaz = points.transform_to(AltAz(location=obs, obstime=Time(str2dt(time))))
 
-    altaz = points.transform_to(AltAz(location=obs, obstime=Time(str2dt(time))))
+        return altaz.az.degree, altaz.alt.degree
 
-    return altaz.az.degree, altaz.alt.degree
+    return vradec2azel(ra_deg, dec_deg, lat_deg, lon_deg, time)

src/pymap3d/ecef.py

@@ -1,16 +1,16 @@
 """ Transforms involving ECEF: earth-centered, earth-fixed frame """
 try:
     from numpy import radians, sin, cos, tan, arctan as atan, hypot, degrees, arctan2 as atan2, sqrt, pi, vectorize
-    from .eci import eci2ecef, ecef2eci
 except ImportError:
     from math import radians, sin, cos, tan, atan, hypot, degrees, atan2, sqrt, pi
 
-    vectorize = eci2ecef = None
+    vectorize = None
 import typing
 from datetime import datetime
 
 from .ellipsoid import Ellipsoid
 from .utils import sanitize
+from .eci import eci2ecef, ecef2eci
 
 # py < 3.6 compatible
 tau = 2 * pi
@@ -331,7 +331,7 @@ def uvw2enu(
 
 
 def eci2geodetic(
-    x: "ndarray", y: "ndarray", z: "ndarray", t: datetime, ell: Ellipsoid = None, deg: bool = True
+    x: "ndarray", y: "ndarray", z: "ndarray", t: datetime, ell: Ellipsoid = None, *, deg: bool = True, use_astropy: bool = True
 ) -> typing.Tuple["ndarray", "ndarray", "ndarray"]:
     """
     convert Earth Centered Internal ECI to geodetic coordinates
@@ -348,10 +348,12 @@ def eci2geodetic(
         ECI z-location [meters]
     t : datetime.datetime, "ndarray"
         UTC time
-    ell : Ellipsoid (optional)
+    ell : Ellipsoid, optional
         planet ellipsoid model
-    deg : bool (optional)
+    deg : bool, optional
         if True, degrees. if False, radians
+    use_astropy : bool, optional
+        use AstroPy (recommended)
 
     Results
     -------
@@ -364,16 +366,21 @@ def eci2geodetic(
 
     eci2geodetic() a.k.a. eci2lla()
     """
-    if eci2ecef is None:
-        raise ImportError("pip install astropy")
 
-    xecef, yecef, zecef = eci2ecef(x, y, z, t)
+    xecef, yecef, zecef = eci2ecef(x, y, z, t, use_astropy=use_astropy)
 
     return ecef2geodetic(xecef, yecef, zecef, ell, deg)
 
 
 def geodetic2eci(
-    lat: "ndarray", lon: "ndarray", alt: "ndarray", t: datetime, ell: Ellipsoid = None, deg: bool = True
+    lat: "ndarray",
+    lon: "ndarray",
+    alt: "ndarray",
+    t: datetime,
+    ell: Ellipsoid = None,
+    *,
+    deg: bool = True,
+    use_astropy: bool = True
 ) -> typing.Tuple["ndarray", "ndarray", "ndarray"]:
     """
     convert geodetic coordinates to Earth Centered Internal ECI
@@ -390,10 +397,12 @@ def geodetic2eci(
         altitude above ellipsoid  (meters)
     t : datetime.datetime, "ndarray"
         UTC time
-    ell : Ellipsoid (optional)
+    ell : Ellipsoid, optional
         planet ellipsoid model
-    deg : bool (optional)
+    deg : bool, optional
         if True, degrees. if False, radians
+    use_astropy: bool, optional
+        use AstroPy (recommended)
 
     Results
     -------
@@ -406,12 +415,9 @@ def geodetic2eci(
 
     geodetic2eci() a.k.a lla2eci()
     """
-    if ecef2eci is None:
-        raise ImportError("pip install astropy")
-
     x, y, z = geodetic2ecef(lat, lon, alt, ell, deg)
 
-    return ecef2eci(x, y, z, t)
+    return ecef2eci(x, y, z, t, use_astropy=use_astropy)
 
 
 def enu2ecef(