diff --git a/pyModeS/c_common.pyx b/pyModeS/c_common.pyx
index 18c1768..ab9f989 100644
--- a/pyModeS/c_common.pyx
+++ b/pyModeS/c_common.pyx
@@ -228,7 +228,7 @@ cpdef int cprNL(double lat):
 
     cdef int nz = 15
     cdef double a = 1 - cos(pi / (2 * nz))
-    cdef double b = cos(pi / 180.0 * fabs(lat)) ** 2
+    cdef double b = cos(pi / 180 * fabs(lat)) ** 2
     cdef double nl = 2 * pi / (acos(1 - a / b))
     NL = floor(nl)
     return NL
diff --git a/pyModeS/decoder/bds/bds06.py b/pyModeS/decoder/bds/bds06.py
index bd7a8f8..46cee1a 100644
--- a/pyModeS/decoder/bds/bds06.py
+++ b/pyModeS/decoder/bds/bds06.py
@@ -27,13 +27,13 @@ def surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref):
     msgbin1 = common.hex2bin(msg1)
 
     # 131072 is 2^17, since CPR lat and lon are 17 bits each.
-    cprlat_even = common.bin2int(msgbin0[54:71]) / 131072.0
-    cprlon_even = common.bin2int(msgbin0[71:88]) / 131072.0
-    cprlat_odd = common.bin2int(msgbin1[54:71]) / 131072.0
-    cprlon_odd = common.bin2int(msgbin1[71:88]) / 131072.0
+    cprlat_even = common.bin2int(msgbin0[54:71]) / 131072
+    cprlon_even = common.bin2int(msgbin0[71:88]) / 131072
+    cprlat_odd = common.bin2int(msgbin1[54:71]) / 131072
+    cprlon_odd = common.bin2int(msgbin1[71:88]) / 131072
 
-    air_d_lat_even = 90.0 / 60
-    air_d_lat_odd = 90.0 / 59
+    air_d_lat_even = 90 / 60
+    air_d_lat_odd = 90 / 59
 
     # compute latitude index 'j'
     j = common.floor(59 * cprlat_even - 60 * cprlat_odd + 0.5)
@@ -43,8 +43,8 @@ def surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref):
     lat_odd_n = float(air_d_lat_odd * (j % 59 + cprlat_odd))
 
     # solution for north hemisphere
-    lat_even_s = lat_even_n - 90.0
-    lat_odd_s = lat_odd_n - 90.0
+    lat_even_s = lat_even_n - 90
+    lat_odd_s = lat_odd_n - 90
 
     # chose which solution corrispondes to receiver location
     lat_even = lat_even_n if lat_ref > 0 else lat_even_s
@@ -60,16 +60,16 @@ def surface_position(msg0, msg1, t0, t1, lat_ref, lon_ref):
         nl = common.cprNL(lat_even)
         ni = max(common.cprNL(lat_even) - 0, 1)
         m = common.floor(cprlon_even * (nl - 1) - cprlon_odd * nl + 0.5)
-        lon = (90.0 / ni) * (m % ni + cprlon_even)
+        lon = (90 / ni) * (m % ni + cprlon_even)
     else:
         lat = lat_odd
         nl = common.cprNL(lat_odd)
         ni = max(common.cprNL(lat_odd) - 1, 1)
         m = common.floor(cprlon_even * (nl - 1) - cprlon_odd * nl + 0.5)
-        lon = (90.0 / ni) * (m % ni + cprlon_odd)
+        lon = (90 / ni) * (m % ni + cprlon_odd)
 
     # four possible longitude solutions
-    lons = [lon, lon + 90.0, lon + 180.0, lon + 270.0]
+    lons = [lon, lon + 90, lon + 180, lon + 270]
 
     # make sure lons are between -180 and 180
     lons = [(l + 180) % 360 - 180 for l in lons]
@@ -99,11 +99,11 @@ def surface_position_with_ref(msg, lat_ref, lon_ref):
 
     mb = common.hex2bin(msg)[32:]
 
-    cprlat = common.bin2int(mb[22:39]) / 131072.0
-    cprlon = common.bin2int(mb[39:56]) / 131072.0
+    cprlat = common.bin2int(mb[22:39]) / 131072
+    cprlon = common.bin2int(mb[39:56]) / 131072
 
     i = int(mb[21])
-    d_lat = 90.0 / 59 if i else 90.0 / 60
+    d_lat = 90 / 59 if i else 90 / 60
 
     j = common.floor(lat_ref / d_lat) + common.floor(
         0.5 + ((lat_ref % d_lat) / d_lat) - cprlat
@@ -114,9 +114,9 @@ def surface_position_with_ref(msg, lat_ref, lon_ref):
     ni = common.cprNL(lat) - i
 
     if ni > 0:
-        d_lon = 90.0 / ni
+        d_lon = 90 / ni
     else:
-        d_lon = 90.0
+        d_lon = 90
 
     m = common.floor(lon_ref / d_lon) + common.floor(
         0.5 + ((lon_ref % d_lon) / d_lon) - cprlon
@@ -153,7 +153,7 @@ def surface_velocity(msg, source=False):
     # ground track
     trk_status = int(mb[12])
     if trk_status == 1:
-        trk = common.bin2int(mb[13:20]) * 360.0 / 128.0
+        trk = common.bin2int(mb[13:20]) * 360 / 128
         trk = round(trk, 1)
     else:
         trk = None
diff --git a/pyModeS/decoder/bds/bds44.py b/pyModeS/decoder/bds/bds44.py
index a2198a3..6bc755a 100644
--- a/pyModeS/decoder/bds/bds44.py
+++ b/pyModeS/decoder/bds/bds44.py
@@ -68,7 +68,7 @@ def wind44(msg):
         return None, None
 
     speed = common.bin2int(d[5:14])  # knots
-    direction = common.bin2int(d[14:23]) * 180.0 / 256.0  # degree
+    direction = common.bin2int(d[14:23]) * 180 / 256  # degree
 
     return round(speed, 0), round(direction, 1)
 
@@ -136,7 +136,7 @@ def hum44(msg):
     if d[49] == "0":
         return None
 
-    hm = common.bin2int(d[50:56]) * 100.0 / 64  # %
+    hm = common.bin2int(d[50:56]) * 100 / 64  # %
 
     return round(hm, 1)
 
diff --git a/pyModeS/decoder/bds/bds50.py b/pyModeS/decoder/bds/bds50.py
index e20bd38..62dd186 100644
--- a/pyModeS/decoder/bds/bds50.py
+++ b/pyModeS/decoder/bds/bds50.py
@@ -78,7 +78,7 @@ def roll50(msg):
     if sign:
         value = value - 512
 
-    angle = value * 45.0 / 256.0  # degree
+    angle = value * 45 / 256  # degree
     return round(angle, 1)
 
 
@@ -102,7 +102,7 @@ def trk50(msg):
     if sign:
         value = value - 1024
 
-    trk = value * 90.0 / 512.0
+    trk = value * 90 / 512.0
 
     # convert from [-180, 180] to [0, 360]
     if trk < 0:
@@ -151,7 +151,7 @@ def rtrk50(msg):
     if sign:
         value = value - 512
 
-    angle = value * 8.0 / 256.0  # degree / sec
+    angle = value * 8 / 256  # degree / sec
     return round(angle, 3)
 
 
diff --git a/pyModeS/decoder/bds/bds53.py b/pyModeS/decoder/bds/bds53.py
index 023f7ef..d7c47b9 100644
--- a/pyModeS/decoder/bds/bds53.py
+++ b/pyModeS/decoder/bds/bds53.py
@@ -78,7 +78,7 @@ def hdg53(msg):
     if sign:
         value = value - 1024
 
-    hdg = value * 90.0 / 512.0  # degree
+    hdg = value * 90 / 512  # degree
 
     # convert from [-180, 180] to [0, 360]
     if hdg < 0:
diff --git a/pyModeS/decoder/bds/bds60.py b/pyModeS/decoder/bds/bds60.py
index 74255db..5ef19c5 100644
--- a/pyModeS/decoder/bds/bds60.py
+++ b/pyModeS/decoder/bds/bds60.py
@@ -86,7 +86,7 @@ def hdg60(msg):
     if sign:
         value = value - 1024
 
-    hdg = value * 90 / 512.0  # degree
+    hdg = value * 90 / 512  # degree
 
     # convert from [-180, 180] to [0, 360]
     if hdg < 0:
diff --git a/pyModeS/extra/aero.py b/pyModeS/extra/aero.py
index 8d6a32c..a27e4cb 100644
--- a/pyModeS/extra/aero.py
+++ b/pyModeS/extra/aero.py
@@ -35,18 +35,18 @@
 fpm = 0.00508  # ft/min -> m/s
 inch = 0.0254  # inch -> m
 sqft = 0.09290304  # 1 square foot
-nm = 1852.0  # nautical mile -> m
+nm = 1852  # nautical mile -> m
 lbs = 0.453592  # pound -> kg
 g0 = 9.80665  # m/s2, Sea level gravity constant
 R = 287.05287  # m2/(s2 x K), gas constant, sea level ISA
-p0 = 101325.0  # Pa, air pressure, sea level ISA
+p0 = 101325  # Pa, air pressure, sea level ISA
 rho0 = 1.225  # kg/m3, air density, sea level ISA
 T0 = 288.15  # K, temperature, sea level ISA
 gamma = 1.40  # cp/cv for air
 gamma1 = 0.2  # (gamma-1)/2 for air
 gamma2 = 3.5  # gamma/(gamma-1) for air
 beta = -0.0065  # [K/m] ISA temp gradient below tropopause
-r_earth = 6371000.0  # m, average earth radius
+r_earth = 6371000  # m, average earth radius
 a0 = 340.293988  # m/s, sea level speed of sound ISA, sqrt(gamma*R*T0)
 
 
@@ -94,8 +94,8 @@ def distance(lat1, lon1, lat2, lon2, H=0):
     """
 
     # phi = 90 - latitude
-    phi1 = np.radians(90.0 - lat1)
-    phi2 = np.radians(90.0 - lat2)
+    phi1 = np.radians(90 - lat1)
+    phi2 = np.radians(90 - lat2)
 
     # theta = longitude
     theta1 = np.radians(lon1)
@@ -158,16 +158,16 @@ def tas2eas(Vtas, H):
 def cas2tas(Vcas, H):
     """Calibrated Airspeed to True Airspeed"""
     p, rho, T = atmos(H)
-    qdyn = p0 * ((1.0 + rho0 * Vcas * Vcas / (7.0 * p0)) ** 3.5 - 1.0)
-    Vtas = np.sqrt(7.0 * p / rho * ((1.0 + qdyn / p) ** (2.0 / 7.0) - 1.0))
+    qdyn = p0 * ((1 + rho0 * Vcas * Vcas / (7 * p0)) ** 3.5 - 1.0)
+    Vtas = np.sqrt(7 * p / rho * ((1 + qdyn / p) ** (2 / 7.0) - 1.0))
     return Vtas
 
 
 def tas2cas(Vtas, H):
     """True Airspeed to Calibrated Airspeed"""
     p, rho, T = atmos(H)
-    qdyn = p * ((1.0 + rho * Vtas * Vtas / (7.0 * p)) ** 3.5 - 1.0)
-    Vcas = np.sqrt(7.0 * p0 / rho0 * ((qdyn / p0 + 1.0) ** (2.0 / 7.0) - 1.0))
+    qdyn = p * ((1 + rho * Vtas * Vtas / (7 * p)) ** 3.5 - 1.0)
+    Vcas = np.sqrt(7 * p0 / rho0 * ((qdyn / p0 + 1.0) ** (2 / 7.0) - 1.0))
     return Vcas
 
 
diff --git a/pyModeS/py_common.py b/pyModeS/py_common.py
index 4310ac3..0b299ee 100644
--- a/pyModeS/py_common.py
+++ b/pyModeS/py_common.py
@@ -199,7 +199,7 @@ def cprNL(lat: float) -> int:
 
     nz = 15
     a = 1 - np.cos(np.pi / (2 * nz))
-    b = np.cos(np.pi / 180.0 * abs(lat)) ** 2
+    b = np.cos(np.pi / 180 * abs(lat)) ** 2
     nl = 2 * np.pi / (np.arccos(1 - a / b))
     NL = floor(nl)
     return NL
diff --git a/tests/test_allcall.py b/tests/test_allcall.py
index e727d4b..b10a839 100644
--- a/tests/test_allcall.py
+++ b/tests/test_allcall.py
@@ -6,7 +6,7 @@ def test_icao():
 
 
 def test_interrogator():
-    assert allcall.interrogator("5D484FDEA248F5") == 22
+    assert allcall.interrogator("5D484FDEA248F5") == "SI6"
 
 
 def test_capability():