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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.

33.4, -97.6 · EM13ei · 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
98.5
km · 61.2 mi
Bearing
106.4°
true · rev 286.4°
Terrain
BLOCKED
79.9 dB diffraction
Propagation
79/100
GOOD
Margin
-14.8
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 volume95 m AGL at the midpoint (286 m above the chord, 143 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 27.2 m) clears with margin. The geometric line of sight is obstructed — buried 77 m below terrain at its worst point.

Great circle
33.374, -97.63 → 33.12, -96.615 · 106.4°
Loss budget · 10 GHz
FSPL (free-space) 152.3 dB
Gaseous (O₂ + H₂O) 0.7 dB
Diffraction 79.9 dB
Rain attenuation 0.0 dB
Total path loss 232.8 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 13.4 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 -232.8 dB
RX antenna gain 30.0 dBi
RX power -154.8 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -14.8 dB
Path weather · HRRR average of 9 samples
Temperature
73.0 °F
22.8 °C
Dewpoint
61.0 °F
16.1 °C
T/Td gap
12.0 °F
6.7 °C
Abs. humidity
13.4
g/m³
Pressure
971.2
mb
PWAT
24.7
mm
BL depth
298.4
m AGL
Refrac. gradient
-111.8
N/km · super-refractive
Propagation factors · 10 GHz 79/100
Rain
100 14%
Humidity
90 13%
PWAT
90 11%
Season
68 11%
T-Td Depression
85 10%
Refractivity
82 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 33.4, -97.6 21.9 °C 16.8 °C 971.2 mb -77.7 271.9 27.8 mm
13% 33.3, -97.5 21.4 °C 17.7 °C 978.1 mb -84.6 320.1 27.9 mm
25% 33.3, -97.4 21.6 °C 18.0 °C 980.7 mb -111.8 315.8 27.0 mm
38% 33.3, -97.2 22.0 °C 17.0 °C 984.4 mb -96.1 313.6 25.7 mm
Midpoint 33.2, -97.1 23.7 °C 14.8 °C 985.8 mb -70.2 338.3 24.0 mm
63% 33.2, -97.0 23.2 °C 14.8 °C 987.3 mb -64.6 296.8 23.3 mm
75% 33.2, -96.9 23.5 °C 15.0 °C 988.3 mb -69.0 279.1 22.7 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 81 at 16:00 UTC · low 68 at 23:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
08:00 78 GOOD
09:00 74 GOOD
10:00 77 GOOD
11:00 76 GOOD
12:00 77 GOOD
13:00 77 GOOD
14:00 77 GOOD
15:00 80 EXCELLENT
16:00 81 EXCELLENT
17:00 80 EXCELLENT
18:00 79 GOOD
19:00 79 GOOD
20:00 78 GOOD
21:00 70 GOOD
22:00 71 GOOD
23:00 68 GOOD
00:00 68 GOOD
01:00 · now 69 GOOD