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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.

33.8, -97.9 · EM13at · 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
143.9
km · 89.4 mi
Bearing
121.2°
true · rev 301.2°
Terrain
BLOCKED
109.3 dB diffraction
Propagation
78/100
GOOD
Margin
-47.9
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 volume203 m AGL at the midpoint (610 m above the chord, 305 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 32.9 m) clears with margin. The geometric line of sight is obstructed — buried 340 m below terrain at its worst point.

Great circle
33.798, -97.937 → 33.12, -96.615 · 121.2°
Loss budget · 10 GHz
FSPL (free-space) 155.6 dB
Gaseous (O₂ + H₂O) 1.0 dB
Diffraction 109.3 dB
Rain attenuation 0.0 dB
Total path loss 265.9 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 13.7 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 -265.9 dB
RX antenna gain 30.0 dBi
RX power -187.9 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -47.9 dB
Path weather · HRRR average of 9 samples
Temperature
73.1 °F
22.8 °C
Dewpoint
61.5 °F
16.4 °C
T/Td gap
11.6 °F
6.4 °C
Abs. humidity
13.7
g/m³
Pressure
967.1
mb
PWAT
26.2
mm
BL depth
307.4
m AGL
Refrac. gradient
-96.7
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 33.8, -97.9 22.9 °C 16.6 °C 976.8 mb -93.8 319.1 29.3 mm
13% 33.7, -97.8 23.2 °C 17.1 °C 975.8 mb -96.7 322.1 29.3 mm
25% 33.6, -97.6 21.0 °C 17.3 °C 967.1 mb -92.7 291.8 28.7 mm
38% 33.5, -97.4 21.9 °C 17.1 °C 975.1 mb -87.1 309.1 28.2 mm
Midpoint 33.5, -97.3 21.9 °C 17.4 °C 979.1 mb -81.7 325.4 27.5 mm
63% 33.4, -97.1 23.3 °C 16.3 °C 985.6 mb -85.8 353.9 25.3 mm
75% 33.3, -96.9 23.2 °C 14.8 °C 987.3 mb -64.6 296.8 23.3 mm
88% 33.2, -96.8 24.1 °C 14.8 °C 985.1 mb -64.2 282.1 21.9 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 84 at 08:00 UTC · low 66 at 21:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
08:00 84 EXCELLENT
09:00 75 GOOD
10:00 77 GOOD
11:00 77 GOOD
12:00 76 GOOD
13:00 75 GOOD
14:00 75 GOOD
15:00 76 GOOD
16:00 74 GOOD
17:00 74 GOOD
18:00 74 GOOD
19:00 78 GOOD
20:00 69 GOOD
21:00 66 GOOD
22:00 68 GOOD
23:00 68 GOOD
00:00 70 GOOD
01:00 · now 74 GOOD