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NTMS Propagation Path calculator

Path Calculator

Point-to-point prediction over HRRR profiles, SRTM terrain and ITU-R P.676 / P.530.

33.5, -97.3 · EM13il · 8.0 ft AGL

33.1, -96.6 · EM13qc · 60.0 ft AGL
A callsign resolves through QRZ's mailing address, then geocoding — the position may be off from where the station actually operates.
Band
Station

Path calculation complete.

HRRR 08:00z · 9/9 path points
Distance
76.4
km · 47.5 mi
Bearing
123.1°
true · rev 303.1°
Terrain
BLOCKED
79.1 dB diffraction
Propagation
78/100
GOOD
Margin
-11.7
dB over CW threshold
Terrain profile · SRTM 30 m + canopy + MS footprints
Line of sight 1st Fresnel Duct layer Horizon ray Common volume

Over the horizon: the two horizon-skimming rays intersect at the common volume57 m AGL at the midpoint (172 m above the chord, 86 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 23.9 m) clears with margin. The geometric line of sight is obstructed — buried 70 m below terrain at its worst point.

Great circle
33.497, -97.303 → 33.12, -96.615 · 123.1°
Loss budget · 10 GHz
FSPL (free-space) 150.1 dB
Gaseous (O₂ + H₂O) 0.5 dB
Diffraction 79.1 dB
Rain attenuation 0.0 dB
Total path loss 229.7 dB
Gas rate 0.0069 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 13.1 g/m³
Power budget
TX power 20.0 dBm (100.0 mW)
TX antenna gain 30.0 dBi
Feed loss (×2) -2.0 dB
EIRP 48.0 dBm
Path loss -229.7 dB
RX antenna gain 30.0 dBi
RX power -151.7 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -11.7 dB
Path weather · HRRR average of 9 samples
Temperature
73.7 °F
23.2 °C
Dewpoint
60.4 °F
15.8 °C
T/Td gap
13.3 °F
7.4 °C
Abs. humidity
13.1
g/m³
Pressure
979.1
mb
PWAT
24.1
mm
BL depth
303.4
m AGL
Refrac. gradient
-91.5
N/km
Propagation factors · 10 GHz 78/100
Rain
100 14%
Humidity
90 13%
PWAT
90 11%
Season
68 11%
T-Td Depression
85 10%
Refractivity
68 10%
Pressure
88 10%
Sky Cover
50 8%
Wind
50 8%
Time of Day
55 4%
Atmospheric profile HRRR 3 km Valid 2026-05-15 08:00 UTC · 9 samples
Point Lat, lon Temp Dewpt Press dN/dh BL m PWAT Duct
Source 33.5, -97.3 21.9 °C 17.4 °C 979.1 mb -81.7 325.4 27.5 mm
13% 33.4, -97.2 21.9 °C 17.4 °C 979.1 mb -81.7 325.4 27.5 mm
25% 33.4, -97.1 23.3 °C 16.3 °C 985.6 mb -85.8 353.9 25.3 mm
38% 33.4, -97.0 22.5 °C 15.6 °C 985.0 mb -83.2 272.8 23.9 mm
Midpoint 33.3, -97.0 23.2 °C 14.8 °C 987.3 mb -64.6 296.8 23.3 mm
63% 33.3, -96.9 24.1 °C 14.8 °C 988.5 mb -59.0 323.9 23.2 mm
75% 33.2, -96.8 24.1 °C 14.8 °C 985.1 mb -64.2 282.1 21.9 mm
88% 33.2, -96.7 23.6 °C 14.9 °C 985.3 mb -68.1 283.7 22.0 mm
Destination 33.1, -96.6 24.1 °C 16.0 °C 987.4 mb -91.5 266.6 22.0 mm
Midpoint vertical profile
18-hour forecast · this path · 10 GHz → steady
Propagation score for this path over the next 18 hours. 0 25 50 75 100
Peak 82 at 16:00 UTC · low 67 at 23:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
08:00 80 EXCELLENT
09:00 77 GOOD
10:00 77 GOOD
11:00 75 GOOD
12:00 76 GOOD
13:00 77 GOOD
14:00 79 GOOD
15:00 79 GOOD
16:00 82 EXCELLENT
17:00 82 EXCELLENT
18:00 72 GOOD
19:00 76 GOOD
20:00 78 GOOD
21:00 70 GOOD
22:00 73 GOOD
23:00 67 GOOD
00:00 70 GOOD
01:00 · now 67 GOOD