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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.

33.3, -96.8 · EM13oh · 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 21:00z · 9/9 path points
Distance
26.3
km · 16.3 mi
Bearing
149.6°
true · rev 329.6°
Terrain
BLOCKED
31.8 dB diffraction
Propagation
69/100
GOOD
Margin
+45.2
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 volume7 m AGL at the midpoint (20 m above the chord, 10 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 14.0 m) clears with margin. The geometric line of sight is obstructed — buried 6 m below terrain at its worst point.

Great circle
33.324, -96.758 → 33.12, -96.615 · 149.6°
Loss budget · 10 GHz
FSPL (free-space) 140.8 dB
Gaseous (O₂ + H₂O) 0.2 dB
Diffraction 31.8 dB
Rain attenuation 0.0 dB
Total path loss 172.8 dB
Gas rate 0.0069 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 15.3 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 -172.8 dB
RX antenna gain 30.0 dBi
RX power -94.8 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin 45.2 dB
Path weather · HRRR average of 9 samples
Temperature
68.0 °F
20.0 °C
Dewpoint
64.4 °F
18.0 °C
T/Td gap
3.5 °F
2.0 °C
Abs. humidity
15.3
g/m³
Pressure
991.7
mb
PWAT
42.4
mm
BL depth
630.0
m AGL
Refrac. gradient
-62.2
N/km
Propagation factors · 10 GHz 69/100
Rain
100 14%
Humidity
95 13%
PWAT
50 11%
Season
68 11%
T-Td Depression
75 10%
Refractivity
55 10%
Pressure
70 10%
Sky Cover
50 8%
Wind
50 8%
Time of Day
18 4%
Atmospheric profile HRRR 3 km Valid 2026-05-10 21:00 UTC · 9 samples
Point Lat, lon Temp Dewpt Press dN/dh BL m PWAT Duct
Source 33.3, -96.8 21.1 °C 18.1 °C 991.7 mb -51.7 758.9 42.3 mm
13% 33.3, -96.7 20.2 °C 18.1 °C 993.1 mb -56.4 659.9 44.6 mm
25% 33.3, -96.7 20.2 °C 18.1 °C 993.1 mb -56.4 659.9 44.6 mm
38% 33.2, -96.7 20.2 °C 18.1 °C 993.1 mb -56.4 659.9 44.6 mm
Midpoint 33.2, -96.7 20.0 °C 18.2 °C 995.4 mb -53.2 781.6 42.2 mm
63% 33.2, -96.7 20.0 °C 18.2 °C 995.4 mb -53.2 781.6 42.2 mm
75% 33.2, -96.7 19.4 °C 17.8 °C 995.0 mb -62.2 456.2 40.3 mm
88% 33.1, -96.6 19.4 °C 17.8 °C 995.0 mb -62.2 456.2 40.3 mm
Destination 33.1, -96.6 19.4 °C 17.8 °C 995.0 mb -62.2 456.2 40.3 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 75 at 10:00 UTC · low 60 at 22:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
21:00 67 GOOD
22:00 60 MARGINAL
23:00 65 GOOD
00:00 63 MARGINAL
01:00 67 GOOD
02:00 61 MARGINAL
03:00 65 GOOD
04:00 69 GOOD
05:00 67 GOOD
06:00 73 GOOD
07:00 73 GOOD
08:00 72 GOOD
09:00 71 GOOD
10:00 75 GOOD
11:00 75 GOOD
12:00 75 GOOD
13:00 · now 75 GOOD