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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.

33.7, -97.6 · EM13eq · 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
111.6
km · 69.4 mi
Bearing
123.5°
true · rev 303.5°
Terrain
BLOCKED
87.0 dB diffraction
Propagation
69/100
GOOD
Margin
-23.2
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 volume122 m AGL at the midpoint (367 m above the chord, 183 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 28.9 m) clears with margin. The geometric line of sight is obstructed — buried 112 m below terrain at its worst point.

Great circle
33.678, -97.615 → 33.12, -96.615 · 123.5°
Loss budget · 10 GHz
FSPL (free-space) 153.4 dB
Gaseous (O₂ + H₂O) 0.8 dB
Diffraction 87.0 dB
Rain attenuation 0.0 dB
Total path loss 241.2 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 7.5 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 -241.2 dB
RX antenna gain 30.0 dBi
RX power -163.2 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -23.2 dB
Path weather · HRRR average of 9 samples
Temperature
80.1 °F
26.7 °C
Dewpoint
45.5 °F
7.5 °C
T/Td gap
34.6 °F
19.2 °C
Abs. humidity
7.5
g/m³
Pressure
974.0
mb
PWAT
14.9
mm
BL depth
2232.5
m AGL
Refrac. gradient
0
N/km
Propagation factors · 10 GHz 69/100
Rain
100 14%
Humidity
82 13%
PWAT
75 11%
Season
68 11%
T-Td Depression
55 10%
Refractivity
50 10%
Pressure
88 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 33.7, -97.6 24.8 °C 8.8 °C 974.0 mb 2197.3 14.3 mm
13% 33.6, -97.5 25.3 °C 9.7 °C 977.9 mb 2012.7 14.7 mm
25% 33.5, -97.4 25.7 °C 8.6 °C 983.5 mb 2069.5 13.7 mm
38% 33.5, -97.2 26.4 °C 8.3 °C 986.2 mb 2113.6 14.2 mm
Midpoint 33.4, -97.1 27.3 °C 7.0 °C 993.0 mb 2235.5 14.1 mm
63% 33.3, -97.0 26.8 °C 7.2 °C 992.2 mb 2249.6 14.1 mm
75% 33.3, -96.9 27.7 °C 6.0 °C 995.5 mb 2360.1 15.5 mm
88% 33.2, -96.7 28.1 °C 5.7 °C 991.9 mb 2354.5 15.8 mm
Destination 33.1, -96.6 28.4 °C 6.3 °C 993.9 mb 2499.5 17.5 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 82 at 11:00 UTC · low 73 at 20:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 73 GOOD
21:00 73 GOOD
22:00 74 GOOD
23:00 74 GOOD
00:00 74 GOOD
01:00 74 GOOD
02:00 76 GOOD
03:00 76 GOOD
04:00 78 GOOD
05:00 78 GOOD
06:00 78 GOOD
07:00 79 GOOD
08:00 80 EXCELLENT
09:00 81 EXCELLENT
10:00 81 EXCELLENT
11:00 82 EXCELLENT
12:00 74 GOOD
13:00 · now 74 GOOD