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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, -99.1 · EM03ll · 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
233.0
km · 144.8 mi
Bearing
99.7°
true · rev 279.7°
Terrain
BLOCKED
124.9 dB diffraction
Propagation
76/100
GOOD
Margin
-68.3
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 volume532 m AGL at the midpoint (1597 m above the chord, 799 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 41.8 m) clears with margin. The geometric line of sight is obstructed — buried 806 m below terrain at its worst point.

Great circle
33.498, -99.081 → 33.12, -96.615 · 99.7°
Loss budget · 10 GHz
FSPL (free-space) 159.8 dB
Gaseous (O₂ + H₂O) 1.6 dB
Diffraction 124.9 dB
Rain attenuation 0.0 dB
Total path loss 286.3 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 11.7 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 -286.3 dB
RX antenna gain 30.0 dBi
RX power -208.3 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -68.3 dB
Path weather · HRRR average of 9 samples
Temperature
74.6 °F
23.7 °C
Dewpoint
57.4 °F
14.1 °C
T/Td gap
17.2 °F
9.6 °C
Abs. humidity
11.7
g/m³
Pressure
961.6
mb
PWAT
25.6
mm
BL depth
303.8
m AGL
Refrac. gradient
-96.1
N/km
Propagation factors · 10 GHz 76/100
Rain
100 14%
Humidity
90 13%
PWAT
90 11%
Season
68 11%
T-Td Depression
70 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, -99.1 26.6 °C 8.5 °C 961.6 mb -38.2 283.4 25.2 mm
13% 33.5, -98.8 25.6 °C 10.0 °C 967.5 mb -71.7 276.0 23.8 mm
25% 33.4, -98.5 24.2 °C 12.6 °C 967.8 mb -77.6 347.8 24.9 mm
38% 33.4, -98.2 21.9 °C 14.1 °C 972.7 mb -61.8 315.4 29.0 mm
Midpoint 33.3, -97.8 22.9 °C 16.6 °C 978.8 mb -83.6 351.3 30.5 mm
63% 33.3, -97.5 22.4 °C 17.0 °C 977.7 mb -86.6 301.3 27.0 mm
75% 33.2, -97.2 22.0 °C 17.0 °C 984.4 mb -96.1 313.6 25.7 mm
88% 33.2, -96.9 23.5 °C 15.0 °C 988.3 mb -69.0 279.1 22.7 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 17:00 UTC · low 66 at 22:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
08:00 75 GOOD
09:00 76 GOOD
10:00 77 GOOD
11:00 79 GOOD
12:00 78 GOOD
13:00 77 GOOD
14:00 77 GOOD
15:00 76 GOOD
16:00 74 GOOD
17:00 81 EXCELLENT
18:00 79 GOOD
19:00 73 GOOD
20:00 68 GOOD
21:00 68 GOOD
22:00 66 GOOD
23:00 68 GOOD
00:00 73 GOOD
01:00 · now 72 GOOD