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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

33.2, -96.5 · EM13se · 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
86.2
km · 53.5 mi
Bearing
113.2°
true · rev 293.2°
Terrain
BLOCKED
87.5 dB diffraction
Propagation
70/100
GOOD
Margin
-21.2
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 volume73 m AGL at the midpoint (218 m above the chord, 109 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 25.4 m) clears with margin. The geometric line of sight is obstructed — buried 112 m below terrain at its worst point.

Great circle
33.497, -97.303 → 33.189, -96.452 · 113.2°
Loss budget · 10 GHz
FSPL (free-space) 151.1 dB
Gaseous (O₂ + H₂O) 0.6 dB
Diffraction 87.5 dB
Rain attenuation 0.0 dB
Total path loss 239.2 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 14.9 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 -239.2 dB
RX antenna gain 30.0 dBi
RX power -161.2 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -21.2 dB
Path weather · HRRR average of 9 samples
Temperature
69.4 °F
20.8 °C
Dewpoint
63.8 °F
17.6 °C
T/Td gap
5.6 °F
3.1 °C
Abs. humidity
14.9
g/m³
Pressure
988.0
mb
PWAT
40.3
mm
BL depth
723.6
m AGL
Refrac. gradient
-61.7
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, -97.3 22.1 °C 16.1 °C 988.0 mb -61.7 937.3 36.5 mm
13% 33.5, -97.2 22.1 °C 16.1 °C 988.0 mb -61.7 937.3 36.5 mm
25% 33.4, -97.1 21.8 °C 18.3 °C 994.4 mb -49.4 719.2 39.1 mm
38% 33.4, -97.0 20.3 °C 18.2 °C 993.8 mb -54.6 627.9 39.6 mm
Midpoint 33.3, -96.9 20.3 °C 18.1 °C 995.6 mb -59.4 649.2 41.7 mm
63% 33.3, -96.8 20.2 °C 18.1 °C 993.1 mb -56.4 659.9 44.6 mm
75% 33.3, -96.7 20.0 °C 18.2 °C 995.4 mb -53.2 781.6 42.2 mm
88% 33.2, -96.6 20.1 °C 17.9 °C 997.2 mb -58.9 600.2 41.5 mm
Destination 33.2, -96.5 20.1 °C 17.9 °C 997.2 mb -58.9 600.2 41.5 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 01:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
21:00 66 GOOD
22:00 70 GOOD
23:00 66 GOOD
00:00 66 GOOD
01:00 60 MARGINAL
02:00 63 MARGINAL
03:00 66 GOOD
04:00 70 GOOD
05:00 68 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 75 GOOD