Radar Model

radarsimpy.Transmitter

class radarsimpy.Transmitter(f, t, tx_power=0, pulses=1, prp=None, f_offset=None, pn_f=None, pn_power=None, channels=[{'location': (0, 0, 0)}])

Bases: object

A class defines basic parameters of a radar transmitter

Parameters:

• f (float or numpy.1darray) –

  Waveform frequency (Hz). If f is a single number, radar transmits a single-tone waveform.

  For linear modulation, specify f with [f_start, f_stop].

  f can alse be a 1-D array of an arbitrary waveform, specify the time with t.

• t (float or numpy.1darray) – Timing of each pulse (s).

• tx_power (float) – Transmitter power (dBm)

• pulses (int) – Total number of pulses

• prp (float) –

  Pulse repetition period (s). prp >= pulse_length. If it is None, prp = pulse_length.

  prp can alse be a 1-D array to specify different repetition period for each pulse. In this case, the length of the 1-D array should equals to the length of pulses

• f_offset (numpy.1darray) – Frequency offset for each pulse (Hz). The length must be the same as pulses.

• pn_f (numpy.1darray) – Frequency of the phase noise (Hz)

• pn_power (numpy.1darray) – Power of the phase noise (dB/Hz)

• channels (list[dict]) –

  Properties of transmitter channels

  [{

  • location (numpy.1darray) –

    3D location of the channel [x, y, z] (m)

  • polarization (numpy.1darray) –

    Antenna polarization [x, y, z]. default = [0, 0, 1] (vertical polarization)

  • delay (float) –

    Transmit delay (s). default 0

  • azimuth_angle (numpy.1darray) –

    Angles for azimuth pattern (deg). default [-90, 90]

  • azimuth_pattern (numpy.1darray) –

    Azimuth pattern (dB). default [0, 0]

  • elevation_angle (numpy.1darray) –

    Angles for elevation pattern (deg). default [-90, 90]

  • elevation_pattern (numpy.1darray) –

    Elevation pattern (dB). default [0, 0]

  • pulse_amp (numpy.1darray) –

    Relative amplitude sequence for pulse’s amplitude modulation. The array length should be the same as pulses. default 0

  • pulse_phs (numpy.1darray) –

    Phase code sequence for pulse’s phase modulation (deg). The array length should be the same as pulses. default 0

  • mod_t (numpy.1darray) –

    Time stamps for waveform modulation (s). default None

  • phs (numpy.1darray) –

    Phase scheme for waveform modulation (deg). default None

  • amp (numpy.1darray) –

    Relative amplitude scheme for waveform modulation. default None

  }]

Variables:

• fc_vect (numpy.1darray) – Center frequency array for the pulses (Hz)

• fc_frame (float) – Center frequency of the whole frame (Hz)

• bandwidth (float) – Bandwith of each pulse (Hz), calculated from max(f) - min(f)

• pulse_length (float) – Dwell time of each pulse (s), calculated from t[-1] - t[0]

• channel_size (int) – Number of transmitter channels

• locations (numpy.2darray) – 3D location of the channels. Size of the aray is [channel_size, 3 <x, y, z>] (m)

• delay (numpy.1darray) – Delay for each channel (s)

• polarization (numpy.1darray) –

  Antenna polarization [x, y, z].

  • Horizontal polarization: [1, 0, 0]

  • Vertical polarization: [0, 0, 1]

• az_angles (list[numpy.1darray]) – Angles for each channel’s azimuth pattern (deg)

• az_patterns (list[numpy.1darray]) – Azimuth pattern for each channel (dB)

• el_angles (list[numpy.1darray]) – Angles for each channel’s elevation pattern (deg)

• el_patterns (list[numpy.1darray]) – Elevation pattern for each channel (dB)

• az_func (list) – Azimuth patterns’ interpolation functions

• el_func (list) – Elevation patterns’ interpolation functions

• antenna_gains (numpy.1darray) – Antenna gain for each channel (dB). Antenna gain is max(az_pattern)

• pulse_mod (list[numpy.1darray]) – Complex modulation code sequence for phase modulation. Lentgh of pulse_mod is the same as pulses

• waveform_mod (list[dict]) –

  Waveform modulation properties for each channel. {

  enabled (bool) – Enable waveform modulation var (numpy.1darray) – Variance of the modulation t (numpy.1darray) – Time stamps for waveform modulation

  }

• box_min (numpy.1darray) – Minimum location of the transmitter box (m)

• box_max (numpy.1darray) – Maximum location of the transmitter box (m)

Waveform

|                       prp
|                  +-----------+
|
|            +---f[1]--->  /            /            /
|                         /            /            /
|                        /            /            /
|                       /            /            /
|                      /            /            /     ...
|                     /            /            /
|                    /            /            /
|                   /            /            /
|      +---f[0]--->/            /            /
|
|                  +-------+
|                 t[0]    t[1]
|
|    Pulse         +--------------------------------------+
|    modulation    |pulse_amp[0]|pulse_amp[1]|pulse_amp[2]|  ...
|                  |pulse_phs[0]|pulse_phs[1]|pulse_phs[2]|  ...
|                  +--------------------------------------+
|
|    Waveform      +--------------------------------------+
|    modulation    |           amp / phs / mod_t          |  ...
|                  +--------------------------------------+

radarsimpy.Receiver

class radarsimpy.Receiver(fs, noise_figure=10, rf_gain=0, load_resistor=500, baseband_gain=0, bb_type='complex', channels=[{'location': (0, 0, 0)}])

Bases: object

A class defines basic parameters of a radar receiver

Parameters:

• fs (float) – Sampling rate (sps)

• noise_figure (float) – Noise figure (dB)

• rf_gain (float) – Total RF gain (dB)

• load_resistor (float) – Load resistor to convert power to voltage (Ohm)

• baseband_gain (float) – Total baseband gain (dB)

• bb_type (string) – Baseband data type, complex or real. Deafult is complex

• channels (list[dict]) –

  Properties of transmitter channels

  [{

  • location (numpy.1darray) –

    3D location of the channel [x, y, z] (m)

  • polarization (numpy.1darray) –

    Antenna polarization [x, y, z]. default = [0, 0, 1] (vertical polarization)

  • azimuth_angle (numpy.1darray) –

    Angles for azimuth pattern (deg). default [-90, 90]

  • azimuth_pattern (numpy.1darray) –

    Azimuth pattern (dB). default [0, 0]

  • elevation_angle (numpy.1darray) –

    Angles for elevation pattern (deg). default [-90, 90]

  • elevation_pattern (numpy.1darray) –

    Elevation pattern (dB). default [0, 0]

  }]

Variables:

• noise_bandwidth (float) – Bandwidth in calculating the noise (Hz). noise_bandwidth = fs / 2

• channel_size (int) – Total number of receiver channels

• locations (numpy.2darray) – 3D location of the channels. Size of the aray is [channel_size, 3 <x, y, z>] (m)

• polarization (numpy.1darray) –

  Antenna polarization [x, y, z].

  • Horizontal polarization: [1, 0, 0]

  • Vertical polarization: [0, 0, 1]

• az_angles (list[numpy.1darray]) – Angles for each channel’s azimuth pattern (deg)

• az_patterns (list[numpy.1darray]) – Azimuth pattern for each channel (dB)

• el_angles (list[numpy.1darray]) – Angles for each channel’s elevation pattern (deg)

• el_patterns (list[numpy.1darray]) – Elevation pattern for each channel (dB)

• az_func (list) – Azimuth patterns’ interpolation functions

• el_func (list) – Elevation patterns’ interpolation functions

• antenna_gains (numpy.1darray) – Antenna gain for each channel (dB). Antenna gain is max(az_pattern)

• box_min (numpy.1darray) – Minimum location of the transmitter box (m)

• box_max (numpy.1darray) – Maximum location of the transmitter box (m)

Receiver noise

|           + n1 = 10*log10(Boltzmann_constant * Ts * 1000)
|           |      + 10*log10(noise_bandwidth)  (dBm)
|           v
|    +------+------+
|    |rf_gain      |
|    +------+------+
|           | n2 = n1 + noise_figure + rf_gain (dBm)
|           v n3 = 1e-3 * 10^(n2/10) (Watts)
|    +------+------+
|    |mixer        |
|    +------+------+
|           | n4 = sqrt(n3 * load_resistor) (V)
|           v
|    +------+------+
|    |baseband_gain|
|    +------+------+
|           | noise amplitude (peak to peak)
|           v n5 = n4 * 10^(baseband_gain / 20) * sqrt(2) (V)

radarsimpy.Radar

class radarsimpy.Radar(transmitter, receiver, location=(0, 0, 0), speed=(0, 0, 0), rotation=(0, 0, 0), rotation_rate=(0, 0, 0), time=0, interf=None, seed=None, **kwargs)

Bases: object

A class defines basic parameters of a radar system

Parameters:

• transmitter (Transmitter) – Radar transmiter

• receiver (Receiver) – Radar Receiver

• location (numpy.1darray) – 3D location of the radar [x, y, z] (m). default [0, 0, 0]

• speed (numpy.1darray) – Speed of the radar (m/s), [vx, vy, vz]. default [0, 0, 0]

• rotation (numpy.1darray) – Radar’s angle (deg), [yaw, pitch, roll]. default [0, 0, 0]

• rotation_rate (numpy.1darray) – Radar’s rotation rate (deg/s), [yaw rate, pitch rate, roll rate] default [0, 0, 0]

• time – Radar firing time instances / frames :type time: float or numpy.1darray

• interf (Radar) – Interference radar. default None

• seed (int) – Seed for noise generator

Variables:

• samples_per_pulse (int) – Number of samples in one pulse

• channel_size (int) – Total number of channels. channel_size = transmitter.channel_size * receiver.channel_size

• virtual_array (numpy.2darray) – Locations of virtual array elements. [channel_size, 3 <x, y, z>]

• timestamp (numpy.3darray) –

  Timestamp for each samples. Frame start time is defined in time. [channes/frames, pulses, samples]

  Channel/frame order in timestamp

  [0] Frame[0] -- Tx[0] -- Rx[0]

  [1] Frame[0] -- Tx[0] -- Rx[1]

  …

  [N] Frame[0] -- Tx[1] -- Rx[0]

  [N+1] Frame[0] -- Tx[1] -- Rx[1]

  …

  [M] Frame[1] -- Tx[0] -- Rx[0]

  [M+1] Frame[1] -- Tx[0] -- Rx[1]