import numpy as np
import matplotlib.pyplot as plt

P_TX = 7E3
LOSS_TX = 10**(5/10)
GAIN_TX = 10**(35/10)
MAX_RANGE = 60E3
TARGET_AREA = 1

def PDMS(tx_power, tx_gain, radar_cross_section, tx_loss, dist_source_target, dist_target_missile):
    tx_p_gain = (tx_power*tx_gain) / (4*np.pi*tx_loss)
    p_ref = radar_cross_section / (dist_source_target**2)
    p_rx = 1 / (4*np.pi*dist_target_missile**2)

    return tx_p_gain * p_ref * p_rx


def main():
    pd_min = PDMS(P_TX, GAIN_TX, TARGET_AREA, LOSS_TX, MAX_RANGE, MAX_RANGE)
    pd_min_db = 10*np.log10(pd_min)
    print(pd_min_db)

    illumination_percent = np.arange(0.1, 1.1, 0.1)
    max_range = MAX_RANGE/illumination_percent

    plt.plot(100*illumination_percent, max_range)
    plt.xlabel("Illumination Percent")
    plt.ylabel("Max Range [km]")
    plt.savefig("illumination-percent-range.png")
    plt.show()
    


if __name__ == "__main__":
    main()