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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, -96.7 · EM13pm · 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
45.6
km · 28.3 mi
Bearing
171.1°
true · rev 351.1°
Terrain
BLOCKED
46.4 dB diffraction
Propagation
70/100
GOOD
Margin
+25.7
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 volume20 m AGL at the midpoint (61 m above the chord, 31 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 18.5 m) clears with margin. The geometric line of sight is obstructed — buried 19 m below terrain at its worst point.

Great circle
33.525, -96.691 → 33.12, -96.615 · 171.1°
Loss budget · 10 GHz
FSPL (free-space) 145.6 dB
Gaseous (O₂ + H₂O) 0.3 dB
Diffraction 46.4 dB
Rain attenuation 0.0 dB
Total path loss 192.3 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 15.1 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 -192.3 dB
RX antenna gain 30.0 dBi
RX power -114.3 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin 25.7 dB
Path weather · HRRR average of 9 samples
Temperature
68.0 °F
20.0 °C
Dewpoint
64.0 °F
17.8 °C
T/Td gap
4.0 °F
2.2 °C
Abs. humidity
15.1
g/m³
Pressure
989.4
mb
PWAT
40.3
mm
BL depth
611.1
m AGL
Refrac. gradient
-67.6
N/km
Propagation factors · 10 GHz 70/100
Rain
100 14%
Humidity
95 13%
PWAT
50 11%
Season
68 11%
T-Td Depression
75 10%
Refractivity
55 10%
Pressure
82 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 33.5, -96.7 21.0 °C 17.2 °C 991.7 mb -67.6 662.0 37.5 mm
13% 33.5, -96.7 20.3 °C 17.6 °C 989.4 mb -62.7 611.2 41.1 mm
25% 33.4, -96.7 20.0 °C 17.7 °C 994.3 mb -57.8 583.6 39.8 mm
38% 33.4, -96.7 20.0 °C 17.7 °C 994.3 mb -57.8 583.6 39.8 mm
Midpoint 33.3, -96.7 20.0 °C 17.7 °C 994.3 mb -57.8 583.6 39.8 mm
63% 33.3, -96.6 20.0 °C 18.2 °C 995.4 mb -53.2 781.6 42.2 mm
75% 33.2, -96.6 20.0 °C 18.2 °C 995.4 mb -53.2 781.6 42.2 mm
88% 33.2, -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 02:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
21:00 69 GOOD
22:00 66 GOOD
23:00 68 GOOD
00:00 69 GOOD
01:00 67 GOOD
02:00 60 MARGINAL
03:00 68 GOOD
04:00 66 GOOD
05:00 67 GOOD
06:00 74 GOOD
07:00 73 GOOD
08:00 73 GOOD
09:00 74 GOOD
10:00 75 GOOD
11:00 75 GOOD
12:00 75 GOOD
13:00 · now 74 GOOD