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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.

33.6, -99.4 · EM03ho · 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
265.4
km · 164.9 mi
Bearing
101.3°
true · rev 281.3°
Terrain
BLOCKED
130.3 dB diffraction
Propagation
78/100
GOOD
Margin
-75.0
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 volume691 m AGL at the midpoint (2073 m above the chord, 1037 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 44.6 m) clears with margin. The geometric line of sight is obstructed — buried 1064 m below terrain at its worst point.

Great circle
33.621, -99.41 → 33.12, -96.615 · 101.3°
Loss budget · 10 GHz
FSPL (free-space) 160.9 dB
Gaseous (O₂ + H₂O) 1.9 dB
Diffraction 130.3 dB
Rain attenuation 0.0 dB
Total path loss 293.0 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 11.4 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 -293.0 dB
RX antenna gain 30.0 dBi
RX power -215.0 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -75.0 dB
Path weather · HRRR average of 9 samples
Temperature
75.9 °F
24.4 °C
Dewpoint
56.5 °F
13.6 °C
T/Td gap
19.3 °F
10.7 °C
Abs. humidity
11.4
g/m³
Pressure
958.7
mb
PWAT
25.3
mm
BL depth
298.0
m AGL
Refrac. gradient
-111.8
N/km · super-refractive
Propagation factors · 10 GHz 78/100
Rain
100 14%
Humidity
90 13%
PWAT
90 11%
Season
68 11%
T-Td Depression
70 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 33.6, -99.4 27.5 °C 9.0 °C 958.7 mb -44.6 298.2 25.4 mm
13% 33.6, -99.1 29.0 °C 6.8 °C 960.8 mb -42.5 286.6 23.2 mm
25% 33.5, -98.7 25.6 °C 10.0 °C 967.5 mb -71.7 276.0 23.8 mm
38% 33.4, -98.4 23.7 °C 12.6 °C 969.8 mb -62.9 324.4 24.9 mm
Midpoint 33.4, -98.0 22.6 °C 15.8 °C 971.7 mb -81.0 327.1 29.2 mm
63% 33.3, -97.7 21.8 °C 17.1 °C 977.7 mb -77.9 314.6 28.5 mm
75% 33.2, -97.3 21.6 °C 18.0 °C 980.7 mb -111.8 315.8 27.0 mm
88% 33.2, -97.0 23.5 °C 17.3 °C 990.4 mb -59.5 272.6 23.5 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 15:00 UTC · low 65 at 20:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
08:00 76 GOOD
09:00 72 GOOD
10:00 76 GOOD
11:00 79 GOOD
12:00 78 GOOD
13:00 78 GOOD
14:00 76 GOOD
15:00 81 EXCELLENT
16:00 74 GOOD
17:00 78 GOOD
18:00 74 GOOD
19:00 66 GOOD
20:00 65 GOOD
21:00 66 GOOD
22:00 65 GOOD
23:00 65 GOOD
00:00 73 GOOD
01:00 · now 69 GOOD