computevoltage.py

import sys
import numpy as np
#pi = 3.1415927

import linecache
from scipy.fftpack import rfft, irfft, rfftfreq
from scipy.interpolate import interp1d

##### antenna response file 
fileleff='HorizonAntenna_leff_loaded.npy' # 'HorizonAntenna_leff_notloaded.npy' if loaded=0
freq,realimp,reactance,theta,phi,lefftheta,leffphi,phasetheta,phasephi=np.load(fileleff) ### this line cost 6-7s


azstep=1 #step in azimuth in npy file
freqscale=1 #freq*2 if h/2 and sizeant/2
outputpower=0 #if wanted output is power
loaded=1 #if antenna is loaded or not in npy file


    #impRLC R = 300;C = 6.5e-12;L = 1e-6; 20 300 MHz
RLp=np.array([0.536733768083299,   0.840010121593293,   1.200896057862110,   1.600090229038176,   2.006667705049151,   2.381373444983652,   2.685327039754095,2.890920915220645,   2.989008053352027,   2.988573924755322,   2.910298546933116,   2.778572562448605,   2.615623513015058,   2.438774302675680,2.260069404472798,   2.087095391770503,   1.924138291818527,   1.773244204213567,   1.635038639773870 ,  1.509302421351773,   1.395352352338537,1.292281470704730,   1.199104504595046 ,  1.114841938895556,   1.038565549999183,   0.969420412709374 ,  0.906632958509609 ,  0.849511074453546, 0.797439919119660,   0.749875669027360,   0.706338496130072 ,  0.666405514438127,   0.629704091546769,   0.595905715891539 ,  0.564720490529909, 0.535892256306097,   0.509194310914832,   0.484425672932856 ,  0.461407833493318,   0.439981938133439,   0.420006344534532 ,  0.401354506652400, 0.383913141085314,   0.367580636870446 ,  0.352265674931463 ,  0.337886027975219 ,  0.324367515703664,   0.311643093771139 ,  0.299652058008190, 0.288339348095085 ,  0.277654937150177,   0.267553295648130,   0.257992919745857,   0.248935915510479 ,  0.240347631749694,   0.232196335171802, 0.22445292247744])
RLp=RLp*100
XLp=np.array([1.149833973427903 ,  1.347001618559050 ,  1.469876468210024,   1.496656923296413,   1.411838459831799,   1.213746617081856 ,  0.919238711558534, 0.561550538777911 ,  0.181259529550333 , -0.184790883266832 , -0.510938360781749,  -0.784380139061162 , -1.002688474655982 , -1.169915727151229, -1.293172262455534 , -1.380332931202411 , -1.438786540600538,  -1.474902574702375,  -1.493909155794964 , -1.499971154708314,  -1.496345170687206,  -1.485548051254960 , -1.469510769217091 , -1.449707994034062,  -1.427262501557595 , -1.403027192021063 , -1.377648559710691,  -1.351615388245273,  -1.325295941574338 , -1.298966315222550 , -1.272832045980507,  -1.247044599699961 , -1.221713972961578 , -1.196918345352935 , -1.172711490165158, -1.149128477825457 , -1.126190075642858 , -1.103906149182129 , -1.082278296775352,  -1.061301893203182,  -1.040967676805738,  -1.021262982755671,  -1.002172701363368 , -0.983680022166382,  -0.965767010753354 , -0.948415054722766 , -0.931605207084645 , -0.915318449184856 , -0.899535890421292,  -0.884238918293781 , -0.869409309431790 , -0.855029309984293 , -0.841081691988703 , -0.827549790949401 , -0.814417528766047 , -0.801669425292115, -0.789290601124629])
XLp=XLp*100
fr=np.arange(20,301,5)
    

    
######For this three lines it already needs several s
#fileleff='butwidebasedoublehflat_4p5mhalf_leff.npy' 
#freq,realimp,reactance,theta,phi,lefftheta,leffphi,phasetheta,phasephi=np.load(fileleff) ### this line cost 6-7s
RL=interp1d(fr, RLp, bounds_error=False, fill_value=0.0)(freq[:,0])
XL=interp1d(fr, XLp, bounds_error=False, fill_value=0.0)(freq[:,0])

#===========================================================================================================
def GRANDtoNEC(zenith=None, azimuth =None):
#===========================================================================================================
    zen = (180-zenith)
    azim = azimuth + 90 # az_ant=az_GRAND +90deg
    if azim>360:
      azim = azim-360
    
    return [zen,azim]

### efield in V/m,azimuth, zenith and alpha in deg, time in s # # # EW=1: EW file, EW=0: NS file
#===========================================================================================================
def get_voltage(time1=None,Ex=None, Ey=None, Ez=None, zenith=None, azimuth =None, EW=1):
#===========================================================================================================
    # Note: azim & zenith are in GRAND conventions
    zen, azim = GRANDtoNEC(zenith,azimuth)
    #print 'get_voltage: computing antenna response for wave with zenith=',zen,'deg, azimuth=',azim,'deg (**NEC conventions**).'
    zen = np.deg2rad(zen)
    azim = np.deg2rad(azim)
    delt = time1[1]-time1[0];
    Fs = 1/delt   
    time_off=time1[0] # time offset, to get absolute time
    time1 = (time1-time1[0]) #resetted to zero
    #print 'Efield signal length: ', time1[-1]*1e9 , 'ns.'

    ##### efield in antenna frame
    szen = np.sin(zen);
    czen = np.cos(zen);
    saz = np.sin(azim);
    caz = np.cos(azim);
    #amplitudet = czen*(caz*Ex+saz*Ey)-szen*Ez  # Wrong because Ex&Ey defined in GRAND ref
    #amplitudep = -saz*Ex+caz*Ey # Wrong because Ex&Ey defined in GRAND ref
    #We have to rotate the Ex & Ey vectors by 90deg around the z axis to project them into the NEC referential 
    #(y_NEC = x_Grand & x_NEC=-y_GRAND, since delta az( NEC- GRAND) =90deg => 90deg rotation around zaxis) 
    amplitudet = czen*(caz*Ey-saz*Ex)-szen*Ez
    amplitudep = -saz*Ey-caz*Ex
    ## for the antenna response switch back to degree
    azim = np.rad2deg(azim)
    zen = np.rad2deg(zen)
    

##################################
    if EW==0: #NS component        
        # still our fake NS component
        azim= azim + 90. #0.5*pi # az=az +90deg, to get antenna response for a rotated shower which would fake the NS antenna component
        if azim >360.:
            azim= azim- 360.


#############################
    nfreq=len(freq[:,0])
    f=np.zeros(nfreq)
    RA=np.zeros(nfreq)
    XA=np.zeros(nfreq)
    ltr=np.zeros(nfreq)
    lta=np.zeros(nfreq)
    lpr=np.zeros(nfreq)
    lpa=np.zeros(nfreq)

    if azstep==5:
        roundazimuth=round(azim/10)*10+round((azim-10*round(azim/10))/5)*5
    elif azstep==1:
        roundazimuth=round(azim)
    else:
        print('Error on azimuth step!')
        return(0)
    if roundazimuth>=91 and roundazimuth<=180:
        roundazimuth=180-roundazimuth
    if roundazimuth>=181 and roundazimuth<=270:
        roundazimuth=roundazimuth-180
    if roundazimuth>=271 and roundazimuth<=360:
        roundazimuth=360-roundazimuth
    for i in range(nfreq):
        f[i]=freq[i,0]*freqscale
        indtheta=np.nonzero(theta[i,:]==round(zen))[0]
        indphi=np.nonzero(phi[i,:]==roundazimuth)[0]
        indcom=np.intersect1d(indtheta,indphi)
        ltr[i]=lefftheta[i,indcom]
       	lta[i]=np.deg2rad(phasetheta[i,indcom]) #*np.pi/180
       	lpr[i]=leffphi[i,indcom]
       	lpa[i]=np.deg2rad(phasephi[i,indcom]) #*np.pi/180
        if loaded==0:
            RA[i]=realimp[i,0]
            XA[i]=reactance[i,0]
            Rlefft=ltr[i]*np.cos(lta[i])
            Xlefft=ltr[i]*np.sin(lta[i])
            Rleffp=lpr[i]*np.cos(lpa[i])
            Xleffp=lpr[i]*np.sin(lpa[i])
            Rleqt=((Rlefft*RL[i]-Xlefft*XL[i])*(RA[i]+RL[i]) + (Rlefft*XL[i]+Xlefft*RL[i])*(XA[i]+XL[i])) / ((RA[i]+RL[i])**2+(XA[i]+XL[i])**2)
            Xleqt=((Rlefft*RL[i]+Xlefft*XL[i])*(XA[i]+XL[i]) + (Rlefft*XL[i]+Xlefft*RL[i])*(RA[i]+RL[i])) / ((RA[i]+RL[i])**2+(XA[i]+XL[i])**2)
            ltr[i]=np.sqrt(Rleqt**2+Xleqt**2)
            print(Rleqt,Xleqt,ltr[i])
            lta[i]=np.arccos(Rleqt/ltr[i])
            Rleqp=((Rleffp*RL[i]-Xleffp*XL[i])*(RA[i]+RL[i]) + (Rleffp*XL[i]+Xleffp*RL[i])*(XA[i]+XL[i])) / ((RA[i]+RL[i])**2+(XA[i]+XL[i])**2)
            Xleqp=((Rleffp*RL[i]+Xleffp*XL[i])*(XA[i]+XL[i]) + (Rleffp*XL[i]+Xleffp*RL[i])*(RA[i]+RL[i])) / ((RA[i]+RL[i])**2+(XA[i]+XL[i])**2)
            lpr[i]=np.sqrt(Rleqp**2+Xleqp**2)
            print(Rleqp,lpr[i])
            lpa[i]=np.arccos(Rleqp/lpr[i])
            
    
    if loaded==0:#phases are not unwrap! so:        
        for i in range(1,nfreq):
            while lpa[i]-lpa[i-1]<-np.pi: #180*np.pi/180:
                lpa[i]=lpa[i]+ 2.*np.pi #360*np.pi/180
            while lpa[i]-lpa[i-1]> np.pi: #180*np.pi/180:
                lpa[i]=lpa[i]- 2.*np.pi #360*np.pi/180
            while lta[i]-lta[i-1]<-np.pi: #180*np.pi/180:
                lta[i]=lta[i]+ 2.*np.pi #360*np.pi/180
            while lta[i]-lta[i-1]>np.pi: #180*np.pi/180:
                lta[i]=lta[i]- 2.*np.pi #360*np.pi/180

    #print(round(zenith),roundazimuth,f,ltr,lta,lpr,lpa,Fs)
    ###############################

    fmin=f[0]
    fmax=f[-1]
    f=f*1e6

    nf  = int(2**np.floor(np.log(len(amplitudet))/np.log(2)))
    while Fs/nf > fmin*1e6:   # <== Make sure that the DFT resolution is at least fmin.
        nf *= 2
    F = rfftfreq(nf)*Fs


    modulust = interp1d(f, ltr, bounds_error=False, fill_value=0.0)(F)
    phaset   = interp1d(f, lta, bounds_error=False, fill_value=0.0)(F)
    modulusp = interp1d(f, lpr, bounds_error=False, fill_value=0.0)(F)
    phasep   = interp1d(f, lpa, bounds_error=False, fill_value=0.0)(F)
    if outputpower:
        RLinter  = interp1d(f, RL, bounds_error=False, fill_value=0.0)(F)

    #print(F,modulust)

    phaset -= phaset[0] # Switch the phase origin to be consistent with a real signal.
    phasep -= phasep[0] # Switch the phase origin to be consistent with a real signal.

    #if we want P=V2/RL -> incorrect
    if outputpower:
        modulusp[RLinter!=0]=modulusp[RLinter!=0]/np.sqrt(RLinter[RLinter!=0])
        modulust[RLinter!=0]=modulust[RLinter!=0]/np.sqrt(RLinter[RLinter!=0])

    #B and D are V in freq domain, they are complex
    A = rfft(amplitudet, nf)
    ct = np.cos(phaset)
    st = np.sin(phaset)
    B = np.zeros(A.shape)
    B[1:-1:2] = modulust[1:-1:2]*(A[1:-1:2]*ct[1:-1:2]-A[2:-1:2]*st[2:-1:2])
    B[2:-1:2] = modulust[2:-1:2]*(A[1:-1:2]*st[1:-1:2]+A[2:-1:2]*ct[2:-1:2])
    B[0]  = A[0]*modulust[0]
    B[-1] = A[-1]*modulust[-1]

    C = rfft(amplitudep, nf)
    cp = np.cos(phasep)
    sp = np.sin(phasep)
    D = np.zeros(C.shape)
    D[1:-1:2] = modulusp[1:-1:2]*(C[1:-1:2]*cp[1:-1:2]-C[2:-1:2]*sp[2:-1:2])
    D[2:-1:2] = modulusp[2:-1:2]*(C[1:-1:2]*sp[1:-1:2]+C[2:-1:2]*cp[2:-1:2])
    D[0]  = C[0]*modulusp[0]
    D[-1] = C[-1]*modulusp[-1]



#we should apply 1/sqrt(RL) to the real part
#and then put vt and vp squared, after ifft

    vt=irfft(B)
    vp=irfft(D)

    if outputpower:
        vt=vt**2
        vp=vp**2
        
    voltage = vp + vt
    timet     = np.arange(0, len(vt))/Fs
    timep     = np.arange(0, len(vp))/Fs
    
    
    print '    Peak to peak voltage amplitude = ', max(voltage) - min(voltage),'muV'

    return(voltage, timet+time_off)



#===========================================================================================================
def effective_zenith(zen, azim, alpha, x_ant, y_ant, z_ant, x_xmax=0, y_xmax=0, z_xmax=3000.):
#===========================================================================================================	
# Effective zenith (computed in GRAND conventions, ie theta>90deg <=> downward)
	zen = np.deg2rad(zen)
	azim = np.deg2rad(azim)
	alpha = np.deg2rad(alpha)
	
	print "input zen, azim, alpha : ", np.rad2deg(zen), np.rad2deg(azim), np.rad2deg(alpha)
	
	#print 'Now computing effective zenith angle to Xmax from antenna location.'
	
	# shower direction: where it goes to
	v = np.array([np.cos(azim)*np.sin(zen), np.sin(azim)*np.sin(zen), np.cos(zen)]) # or *-1: change the direction
	# vector for zenith=90
	b = np.array([np.cos(azim), np.sin(azim) ,0.])
	# projection v onto b
	v_p= np.linalg.norm(v)* np.cos(0.5*np.pi-zen) *b/np.linalg.norm(b)
	v_p /=np.linalg.norm(v_p)

	
	Xmax= np.array([x_xmax,y_xmax,z_xmax])
	#print 'Xmax position:',Xmax
	#print(v, Xmax)
			
	ant= np.array([x_ant, y_ant, z_ant])  # antenna position
	# unit vetor between xmax and antenna
	u_xmax =  Xmax - ant  
	u_xmax = u_xmax/np.linalg.norm(u_xmax) 
	#print u_xmax
		
	# antenna vector
	# at the moment slope always facing the shower => azim_ant = 180. -azim, mountain slope alpha works as zenith
	u_ant= np.array([ np.cos(np.pi-azim)* np.sin(alpha),  np.sin(np.pi-azim)* np.sin(alpha), np.cos(alpha)])
	#print(u_ant)
		
	# get effective zenith, the angle between antenna vector and vector between xmax and antenna
	cos_zen_eff= np.dot(u_xmax, u_ant)
	zen_eff=  np.arccos(cos_zen_eff)
	zen_eff = 180-np.rad2deg(zen_eff)
	
	#zen_eff=180-zen_eff

	return zen_eff


#===========================================================================================================
# Compute the time dependent voltage
#===========================================================================================================
if __name__ == '__main__':
  
  if len(sys.argv)<4:
        print 'Wrong number of arguments. Usage: python computevoltage.py [zenith] [azimuth] [slope] [path to traces] [effective 1/0]  [opt: AntennaID] [opt: antenna x,y,z]'
    	## example: python computevoltage.py 85 45 0/1 ./ 7 100 100 1000
	## if effective zenith wanted -- inside function, set effective to 1 plus hand over antenna postion x,y,z in m:  python computevoltage.py 85 45 0 ./ 0 a0.trace 0 34000 3000
  	## Zenith and azimuth here in deg & using GRAND conventions
	sys.exit(0)
  
  # Read zen and az value from input, in GRAND convention
  zenith_sim=float(sys.argv[1])  # 
  azimuth_sim=float(sys.argv[2])

  ## include a mountain slope - correction of zenith angle
  alpha_sim=float(sys.argv[3])

  # which efield trace do you wanna read in. to be consistent the script works with the antenna ID
  path=sys.argv[4] #folder containing the traces and where the output should go to
  
  # decide if the effectice zenith should be calculated (1) or not (0)
  effective = float(sys.argv[5])
  
  ###Handing over one antenna or a whole array  
  if len(sys.argv)==7: # just one specif antenna handed over
    start=int(sys.argv[6]) # antenna ID
    end=start+1
    print "single antenna with ID: ", str(start)," handed over"
  if  len(sys.argv)<7: # grep all antennas from the antenna file
  
    positions=np.genfromtxt(path+'/antpos.dat')
    start=0
    end=len(positions)
    print "Array with ", end, " antennas handed over"
  
  
  
 ###### loop  over l
  for l in range(start,end):
    efieldtxt=path+'/a'+str(l)+'.trace'

    print 'Wave direction: zenith = ', zenith_sim, ' deg, azimuth = ', azimuth_sim, 'deg. (GRAND conventions), mountain slope: ', alpha_sim, 'deg.'
    print 'Efield file: ', efieldtxt
    
    # Model the input signal.
    try: 
        time1_sim, Ex_sim, Ey_sim,Ez_sim = np.loadtxt(efieldtxt,delimiter=' ',usecols=(0,1,2,3),unpack=True)
    except IOError:
        continue

    # NOTE: adapt to your time from whatever to s
    time1_sim= time1_sim*1e-9 # time has to be handed in s


    #print 'Now computing antenna response...'
    if effective==1:
        
    # Compute effective zenith
            # First get antenna position
            if len(sys.argv)==10:
                    print 'Reading antenna position from parameter input.'
                    x_sim = float(sys.argv[7])
                    y_sim = float(sys.argv[8])
                    z_sim = float(sys.argv[9])
    
            else :
                    try :
                            #print 'Trying to read antenna position from antpos.dat file...'
                            numberline = int(l) + 1
                            line = linecache.getline(path+'/antpos.dat', numberline)
                            [x_sim, y_sim, z_sim] = map(float, line.split())
                            print 'Read antenna position from antpos.dat file... Antenna',l,' at position [', x_sim, y_sim, z_sim,'].'
    
                    except : 
                            print 'No antenna position file found, please put antpos.dat in', path, 'or enter antenna positions as arguments.'
                            sys.exit()
            # Then compute Xmax
            injection_height = 346 ## always refeering to sealevel
            hor_dist=8000. # approx. horizontal distance from injection point to xmax
            #print 'Now computing Xmax position from injection height=',injection_height,'m, horizontal distance to Xmax= ',hor_dist,'m and (zen,azim) values.'
            caz = np.cos(np.deg2rad(azimuth_sim))
            saz = np.sin(np.deg2rad(azimuth_sim))
            czen = np.cos(np.deg2rad(zenith_sim))
            szen = np.sin(np.deg2rad(zenith_sim))
            Xmax = hor_dist/szen*np.array([caz*szen, saz*szen, czen])+np.array([0,0,injection_height])
            #print 'Xmax = ',Xmax
            # Finally compute effective zenith
            zenith_eff = effective_zenith(zenith_sim, azimuth_sim, alpha_sim, x_sim, y_sim, z_sim, Xmax[0], Xmax[1], Xmax[2])
            print "zenith effective: ", zenith_eff # deg

    else: # in case effective zenith not wanted, one still has to account for mountain slope 
            ## zenith: correct for mountain slope
            zenith_eff= 180.-(zenith_sim+alpha_sim) # in antenna convention
            zenith_eff= 180.- zenith_eff # back to GRAND conventions
        
    #print 'Effective zenith (in GRAND conventions): ', zenith_eff,' deg.'	  
    #print "Azimuth (in GRAND conventions) ", azimuth_sim,' deg.'    
    if zenith_eff < 90 :
            print ' --- Wave coming from ground (GRAND zenith smaller than 90deg), antenna response not computed for that angle. Abort --- '
            exit()

    # Compute the output voltage for EW component
    print '*** Computing EW voltage...'
    voltage_EW, timeEW  = get_voltage( time1=time1_sim,Ex=Ex_sim, Ey=Ey_sim, Ez=Ez_sim, zenith=zenith_eff, azimuth=azimuth_sim, EW=1)

    # Compute the output voltage for NS component -- TODO add here the correct antenna file at some point
    print '*** Computing SN voltage...'
    voltage_NS, timeNS = get_voltage( time1=time1_sim,Ex=Ex_sim, Ey=Ey_sim, Ez=Ez_sim, zenith=zenith_eff, azimuth=azimuth_sim, EW=0)

    #pl.savetxt(path+'out_'+str(l)+'.txt', (timeEW, voltage_EW, voltage_NS), newline='\r\n')#, voltage_NS)) # is not working correctly

    f = file(path+'/out_'+str(l)+'.txt',"w")
    for i in np.arange(len(timeEW)):
                print >>f,"%1.5e	%1.2e	%1.2e" % (timeEW[i], voltage_EW[i], voltage_NS[i] ) # same number of digits as input
    f.close()



    ###plots
    DISPLAY=0
    if DISPLAY==1:
        import pylab as pl
        import matplotlib.pyplot as plt
        plt.figure(1,  facecolor='w', edgecolor='k')
        plt.subplot(211)
        plt.plot(time1_sim*1e9,Ey_sim, label="Ey = EW")
        plt.plot(time1_sim*1e9,Ex_sim, label="Ex = NS")
        plt.plot(time1_sim*1e9,Ez_sim, label="Ez = UP")
        plt.xlabel('Time (nsec)')
        plt.ylabel('Electric field (muV/m)')
        plt.legend(loc='best')
        plt.subplot(212)
        plt.plot(timeEW*1e9,voltage_EW, label="EW")
        plt.plot(timeNS*1e9,voltage_NS, label="NS")
        plt.xlabel('Time (nsec)')
        plt.ylabel('Voltage (muV)')
        plt.legend(loc='best')

        plt.show()