Source code for sorts.radar.radar

#!/usr/bin/env python

'''This module is used to define the radar system

'''
import copy
import numpy as np

from .. import passes

class Radar(object):
    '''A network of transmitting and receiving radar stations.
        
        :ivar list tx: List of transmitting sites, i.e. instances of :class:`sorts.radar.TX`
        :ivar list rx: List of receiving sites, i.e. instances of :class:`sorts.radar.RX`
        :ivar float max_off_axis: Maximum angle between pointing direction and a received signal.
        :ivar float min_SNRdb: Minimum SNR detectable by radar system in dB (after coherent integration).

        :param list tx: List of transmitting sites, i.e. instances of :class:`sorts.radar.TX`
        :param list rx: List of receiving sites, i.e. instances of :class:`sorts.radar.RX`
        :param float max_off_axis: Maximum angle between pointing direction and a received signal.
        :param float min_SNRdb: Minimum SNR detectable by radar system in dB (after coherent integration).

    '''
    def __init__(self, tx, rx, max_off_axis=90.0, min_SNRdb=10.0):
        self.tx = tx
        self.rx = rx
        self.max_off_axis = max_off_axis
        self.min_SNRdb = min_SNRdb


    def copy(self):
        '''Create a deep copy of the radar system.
        '''
        ret = Radar(
            tx = [],
            rx = [],
            max_off_axis = copy.deepcopy(self.max_off_axis),
            min_SNRdb = copy.deepcopy(self.min_SNRdb),
        )
        for tx in self.tx:
            ret.tx.append(tx.copy())
        for rx in self.rx:
            ret.rx.append(rx.copy())
        return ret


    def set_beam(self, beam):
        '''Sets the radiation pattern for transmitters and receivers.
        
        :param pyant.Beam beam: The radiation pattern to set for radar system.
        '''
        self.set_tx_beam(beam)
        self.set_rx_beam(beam)


    def set_tx_beam(self, beam):
        '''Sets the radiation pattern for transmitters.
        
        :param pyant.Beam beam: The radiation pattern to set for radar system.
        '''
        for tx in self.tx:
            tx.beam = beam.copy()

    def set_rx_beam(self, beam):
        '''Sets the radiation pattern for receivers.
        
        :param pyant.Beam beam: The radiation pattern to set for radar system.
        '''
        for rx in self.rx:
            rx.beam = beam.copy()


    def find_passes(self, t, states, cache_data=True):
        '''Finds all passes that are simultaneously inside a transmitter station FOV and a receiver station FOV. 

            :param numpy.ndarray t: Vector of times in seconds to use as a base to find passes.
            :param numpy.ndarray states: ECEF states of the object to find passes for.
            :return: list of passes indexed by first tx-station and then rx-station.
            :rtype: list of list of sorts.Pass
        '''
        rd_ps = []
        for txi,tx in enumerate(self.tx):
            rd_ps.append([])
            for rxi,rx in enumerate(self.rx):
                txrx = passes.find_simultaneous_passes(t, states, [tx, rx], cache_data=cache_data)
                for ps in txrx:
                    ps.station_id = [txi, rxi]
                rd_ps[-1].append(txrx)
        return rd_ps