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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 · 30.0 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 20:00z · 9/9 path points
Distance
76.4
km · 47.5 mi
Bearing
123.1°
true · rev 303.1°
Terrain
BLOCKED
82.0 dB diffraction
Propagation
68/100
GOOD
Margin
-14.7
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 78 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 82.0 dB
Rain attenuation 0.0 dB
Total path loss 232.7 dB
Gas rate 0.0069 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 7.0 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 -232.7 dB
RX antenna gain 30.0 dBi
RX power -154.7 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -14.7 dB
Path weather · HRRR average of 9 samples
Temperature
81.0 °F
27.2 °C
Dewpoint
43.9 °F
6.6 °C
T/Td gap
37.1 °F
20.6 °C
Abs. humidity
7.0
g/m³
Pressure
986.4
mb
PWAT
13.9
mm
BL depth
2268.5
m AGL
Refrac. gradient
0
N/km
Propagation factors · 10 GHz 68/100
Rain
100 14%
Humidity
82 13%
PWAT
75 11%
Season
68 11%
T-Td Depression
55 10%
Refractivity
50 10%
Pressure
82 10%
Sky Cover
50 8%
Wind
50 8%
Time of Day
18 4%
Atmospheric profile HRRR 3 km Valid 2026-05-03 20:00 UTC · 9 samples
Point Lat, lon Temp Dewpt Press dN/dh BL m PWAT Duct
Source 33.5, -97.3 26.3 °C 8.5 °C 986.4 mb 2119.6 13.6 mm
13% 33.4, -97.2 26.3 °C 8.5 °C 986.4 mb 2119.6 13.6 mm
25% 33.4, -97.1 27.3 °C 8.1 °C 993.0 mb 2239.7 13.9 mm
38% 33.4, -97.0 26.8 °C 7.4 °C 992.3 mb 2228.2 13.2 mm
Midpoint 33.3, -97.0 27.1 °C 7.1 °C 994.6 mb 2296.0 13.4 mm
63% 33.3, -96.9 27.8 °C 6.5 °C 995.5 mb 2387.5 15.4 mm
75% 33.2, -96.8 28.1 °C 4.7 °C 992.1 mb 2338.5 14.1 mm
88% 33.2, -96.7 27.2 °C 4.7 °C 992.1 mb 2309.6 13.7 mm
Destination 33.1, -96.6 28.2 °C 3.9 °C 994.1 mb 2377.9 13.9 mm
Midpoint vertical profile
17-hour forecast · this path · 10 GHz → steady
Propagation score for this path over the next 17 hours. 0 25 50 75 100
Peak 81 at 10:00 UTC · low 72 at 21:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 74 GOOD
21:00 72 GOOD
22:00 73 GOOD
23:00 72 GOOD
00:00 75 GOOD
01:00 75 GOOD
02:00 75 GOOD
03:00 78 GOOD
04:00 77 GOOD
05:00 79 GOOD
06:00 77 GOOD
07:00 78 GOOD
08:00 77 GOOD
09:00 79 GOOD
10:00 81 EXCELLENT
11:00 73 GOOD
12:00 · now 74 GOOD