diff --git a/gstlal-inspiral/tests/dtdphitest.py b/gstlal-inspiral/tests/dtdphitest.py
index 80c15a3b3f792c05cb558872e714a6e2021a3bec..22b22024b915ae78b5654e6ba1e14e139f7a0048 100644
--- a/gstlal-inspiral/tests/dtdphitest.py
+++ b/gstlal-inspiral/tests/dtdphitest.py
@@ -5,6 +5,13 @@ import lal
 from gstlal.stats import inspiral_extrinsics
 
 import matplotlib
+matplotlib.rcParams['text.usetex'] = True
+matplotlib.rcParams['lines.markersize'] = 2
+matplotlib.rcParams['lines.linewidth'] = 1
+matplotlib.rcParams['font.size'] = 10
+matplotlib.rcParams['savefig.dpi'] = 300
+matplotlib.rcParams['text.latex.preamble'].append(r'\usepackage{amsmath}')
+matplotlib.rcParams['legend.fontsize'] = 10
 matplotlib.use('Agg')
 from matplotlib import pyplot
 
@@ -36,52 +43,63 @@ def random_source(R = R, X = X, epoch = lal.LIGOTimeGPS(0), gmst = lal.Greenwich
 	return T, Deff, phi
 
 
-ndraws = 1000000
+ndraws = 100000 #100000 maybe take 10min to iterate
 delta_phi_HV = []
 delta_t_HV = []
 i = 0
 
+# the following cov matrix elements were derived from running `gstlal_inspiral_compute_dtdphideff_cov_matrix --psd-xml share/O3/2019-05-09-H1L1V1psd_new.xml.gz --H-snr 5 --L-snr 7.0 --V-snr 2.25`
+covmat = [[0.000001, 0.000610], [0.000610, 0.648023]]
+sigmadd = 0.487371
 while i < ndraws:
 	t,d,p = random_source()
 	# Use EXACTLY the same covariance matrix assumptions as the gstlal
 	# code.  It could be a bad assumption, but we are testing the method
 	# not the assumptions by doing this.
-	dpHV = p["H"] - p["V"] + numpy.random.randn() * inspiral_extrinsics.TimePhaseSNR.sigma["phase"]
-	dtHV = t["H"] - t["V"] + numpy.random.randn() * inspiral_extrinsics.TimePhaseSNR.sigma["time"]
-	rdHV = d["H"] / d["V"] - 1.0 + numpy.random.randn() * inspiral_extrinsics.TimePhaseSNR.sigma["deff"]
+	mean = [t["H"] - t["V"], p["H"] - p["V"]]
+	dtHV, dpHV = numpy.random.multivariate_normal(mean, covmat)
+	rdHV = numpy.log(d["H"] / d["V"]) + numpy.random.randn() * sigmadd
 	# only choose things with almost the same effective distance ratio for
 	# this test to agree with setting the same horizon and snr below
-	if 0.1 >= rdHV >= -0.1:
+	if numpy.log(1.1 + 0.1) >= rdHV >= numpy.log(1.1 - 0.1): # 1.1 here comes from Deff_V1 / Deff_H1 = (110/5) / (45/2.25)
 		delta_phi_HV.append(dpHV)
 		delta_t_HV.append(dtHV)
 		print i
 		i += 1
-		
 
-num = 100
-dphivec = numpy.linspace(-2 * numpy.pi, 2 * numpy.pi, num)
-dtvec = numpy.linspace(-0.028, 0.028, num)
-DPProb = numpy.zeros(num)
-DTProb = numpy.zeros(num)
+
+num1 = 100
+num2 = 101
+dtvec = numpy.linspace(-0.028, 0.028, num1)
+dphivec = numpy.linspace(-2 * numpy.pi, 2 * numpy.pi, num2)
+DTProb = numpy.zeros(num1)
+DPProb = numpy.zeros(num2)
+Prob = numpy.zeros((num1,num2))
 
 for j, dt in enumerate(dtvec):
 	for i, dp in enumerate(dphivec):
 		t = {"H1": 0, "V1": dt}
 		phi = {"H1": 0, "V1": dp}
-		snr = {"H1": 1., "V1": 1.}
-		horizon = {"H1": 1., "V1": 1.}
+		snr = {"H1": 5., "V1": 2.25} # our choice of characteristic SNR
+		horizon = {"H1": 110., "V1": 45.} # typical horizon distance taken from the summary page on 2019 May 09.
 		# signature is (time, phase, snr, horizon)
 		p = TPDPDF.time_phase_snr(t, phi, snr, horizon)
+		Prob[j,i] = p
 		DPProb[i] += p
 		DTProb[j] += p
 
-pyplot.figure(figsize=(10,4))
-pyplot.subplot(121)
-pyplot.hist(delta_phi_HV, dphivec, normed = True)
-pyplot.plot(dphivec, DPProb / numpy.sum(DPProb) / (dphivec[1] - dphivec[0]))
-pyplot.xlabel("H phase - V phase")
-pyplot.subplot(122)
-pyplot.hist(delta_t_HV, dtvec, normed = True)
-pyplot.plot(dtvec, DTProb / numpy.sum(DTProb) / (dtvec[1] - dtvec[0]))
-pyplot.xlabel("H time - V time")
-pyplot.savefig("HVtest.png")
+pyplot.figure(figsize=(7.5,7.5))
+pyplot.subplot(221)
+pyplot.hist(delta_phi_HV, dphivec, normed = True, label = "Simulation")
+pyplot.plot(dphivec, DPProb / numpy.sum(DPProb) / (dphivec[1] - dphivec[0]), label ="Direct Calculation")
+pyplot.ylabel(r"""$P(\Delta\phi | s, D_H = D_V, \rho_H = \rho_V)$""")
+pyplot.legend(bbox_to_anchor=(1, 1), loc='upper left', ncol=1)
+pyplot.subplot(223)
+pyplot.pcolor(dphivec, dtvec, Prob)
+pyplot.xlabel(r"""$\phi_H - \phi_V$""")
+pyplot.ylabel(r"""$t_H - t_V$""")
+pyplot.subplot(224)
+pyplot.hist(delta_t_HV, dtvec, normed = True, orientation = "horizontal")
+pyplot.plot(DTProb / numpy.sum(DTProb) / (dtvec[1] - dtvec[0]), dtvec)
+pyplot.xlabel(r"""$P(\Delta t | s, D_H = D_V, \rho_H = \rho_V)$""")
+pyplot.savefig("HVPDF.pdf")