Sensor Constants¶

platform:	Unix, Windows, Mac
synopsis:	Gets a ISR sensor constants and calculates theoretical beam patterns.

sensorConstants.AMISR_Pattern(AZ, EL, Az0, El0)¶

Returns the AMISR pattern in the direction of the array face.

This function will create an idealized antenna pattern for the AMISR array. The pattern is not normalized. The antenna is assumed to made of a grid of ideal cross dipole elements. In the array every other column is shifted by 1/2 dy. The parameters are taken from the AMISR spec and the method for calculating the field is derived from a report by Adam R. Wichman. The inputs for the az and el coordinates can be either an array or scalar. If both are arrays they must be the same shape.

Parameters:	Az (`numpy array`) – Azimuth angles in degrees. El (`numpy array`) – Elevation angles in degrees. Az_0 (float) – The azimuth pointing angle in degrees. El_0 (float) – The elevation pointing angle in degrees.
Returns:	Patout (`numpy array`) – The normalized radiation density.

sensorConstants.AMISR_Patternadj(Az, El, Az0, El0, Angleoffset)¶

This function will call AMISR beam patern function after it rotates the coordinates given the offset of the phased array.

Parameters:	Az (`numpy array`) – Azimuth angles in degrees. El (`numpy array`) – Elevation angles in degrees. Az_0 (float) – The azimuth pointing angle in degrees. El_0 (float) – The elevation pointing angle in degrees. Angleoffset (list) – A 2 element list holding the offset of the face of the array from north.
Returns:	Beam_Pattern (`numpy array`) – The relative beam pattern from the azimuth points.

sensorConstants.Circ_Ant_Pattern(EL, r, lamb)¶

Returns the pattern for a circular dish antenna.

This function will create an idealized antenna pattern for a circular antenna array. The pattern is not normalized. The antenna is assumed to made of a grid of ideal cross dipole elements. In the array every other column is shifted by 1/2 dy. The parameters are taken from the AMISR spec and the method for calculating the field is derived from a report by Adam R. Wichman. The inputs for the az and el coordinates can be either an array or scalar. If both are arrays they must be the same shape.

Parameters:	EL (`numpy array`) – The elevation coordinates in radians. Vertical is at zero radians. r (float) – Radius of the antenna in meters. lamb (float) – wavelength of radiation in meters.
Returns:	Patout (`numpy array`) – The normalized radiation density.

sensorConstants.Millstone_Pattern(Az, El, Az0, El0, Angleoffset)¶

Gives the ideal antenna pattern for the MISA dish at Milstone hill.

This function will call circular antenna beam patern function after it rotates the coordinates given the pointing direction.

Parameters:	Az (`numpy array`) – Azimuth angles in degrees. El (`numpy array`) – Elevation angles in degrees. Az_0 (float) – The azimuth pointing angle in degrees. El_0 (float) – The elevation pointing angle in degrees. Angleoffset (list) – A 2 element list holding the offset of the face of the array from north.
Returns:	Beam_Pattern (`numpy array`) – The relative beam pattern from the azimuth points.

sensorConstants.Sond_Pattern(Az, El, Az0, El0, Angleoffset)¶

Gives the ideal antenna pattern for the Sondestrom radar.

This function will call circular antenna beam patern function after it rotates the coordinates given the pointing direction.

Parameters:	Az (`numpy array`) – Azimuth angles in degrees. El (`numpy array`) – Elevation angles in degrees. Az_0 (float) – The azimuth pointing angle in degrees. El_0 (float) – The elevation pointing angle in degrees. Angleoffset (list) – A 2 element list holding the offset of the face of the array from north.
Returns:	Beam_Pattern (`numpy array`) – The relative beam pattern from the azimuth points.

sensorConstants.getConst(typestr, angles=None)¶

Get the constants associated with a specific radar system. This will fill out a dictionary with all of the parameters.

Parameters:

type (str) – Name of the radar system.
angles (numpy array) – Nx2 array where each row is an az, el pair in degrees.

Returns:

sensdict (dict[str, obj]) –

Holds the different sensor constants.:

{
        'Name': radar name,
        'Pt': Transmit power in W,
        'k': wave number in rad/m,
        'lamb': Wave length in m,
        'fc': Carrier Frequency in Hz,
        'fs': Sampling frequency in Hz,
        'taurg': Pulse length number of samples,
        'Tsys': System Temperature in K,
        'BeamWidth': Tuple of beamwidths in degrees,
        'Ksys': ,
        'BandWidth': Filter bandwidth in Hz,
        'Angleoffset': Tuple of angle offset,
        'ArrayFunc': Function to calculate antenna pattern,
        't_s': Sampling time in s
}

sensorConstants.get_files(fname)¶

Gets the hdf5 files associated with the radar.

Parameters:	fname (str) – Name for the radar.
Returns:	newpath (str) – String holding the location for the file.