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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.

31.6, -98.4 · EM01sn · 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
243.1
km · 151.1 mi
Bearing
44.2°
true · rev 224.2°
Terrain
BLOCKED
124.0 dB diffraction
Propagation
68/100
GOOD
Margin
-67.9
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 volume580 m AGL at the midpoint (1740 m above the chord, 870 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 42.7 m) clears with margin. The geometric line of sight is obstructed — buried 807 m below terrain at its worst point.

Great circle
31.565, -98.435 → 33.12, -96.615 · 44.2°
Loss budget · 10 GHz
FSPL (free-space) 160.2 dB
Gaseous (O₂ + H₂O) 1.7 dB
Diffraction 124.0 dB
Rain attenuation 0.0 dB
Total path loss 285.9 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 6.3 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 -285.9 dB
RX antenna gain 30.0 dBi
RX power -207.9 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -67.9 dB
Path weather · HRRR average of 9 samples
Temperature
79.4 °F
26.3 °C
Dewpoint
41.1 °F
5.0 °C
T/Td gap
38.3 °F
21.3 °C
Abs. humidity
6.3
g/m³
Pressure
964.0
mb
PWAT
12.8
mm
BL depth
2155.6
m AGL
Refrac. gradient
0
N/km
Propagation factors · 10 GHz 68/100
Rain
100 14%
Humidity
70 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 31.6, -98.4 22.4 °C 6.9 °C 964.0 mb 1688.8 11.7 mm
13% 31.8, -98.2 24.6 °C 6.6 °C 974.4 mb 1929.8 13.4 mm
25% 32.0, -98.0 25.4 °C 5.8 °C 978.3 mb 2042.3 12.6 mm
38% 32.1, -97.8 25.6 °C 6.0 °C 981.8 mb 2038.5 12.3 mm
Midpoint 32.3, -97.5 26.7 °C 5.4 °C 986.5 mb 2296.8 12.9 mm
63% 32.5, -97.3 26.9 °C 4.9 °C 990.3 mb 2316.4 12.4 mm
75% 32.7, -97.1 28.5 °C 2.4 °C 996.2 mb 2374.9 11.6 mm
88% 32.9, -96.8 28.4 °C 3.6 °C 999.3 mb 2334.7 14.1 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 83 at 07:00 UTC · low 66 at 23:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 74 GOOD
21:00 74 GOOD
22:00 67 GOOD
23:00 66 GOOD
00:00 67 GOOD
01:00 68 GOOD
02:00 70 GOOD
03:00 74 GOOD
04:00 72 GOOD
05:00 80 EXCELLENT
06:00 75 GOOD
07:00 83 EXCELLENT
08:00 82 EXCELLENT
09:00 80 EXCELLENT
10:00 72 GOOD
11:00 76 GOOD
12:00 · now 76 GOOD