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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.

33.8, -97.9 · EM13at · 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 20:00z · 9/9 path points
Distance
153.5
km · 95.4 mi
Bearing
115.8°
true · rev 295.8°
Terrain
BLOCKED
113.3 dB diffraction
Propagation
69/100
GOOD
Margin
-52.6
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 volume231 m AGL at the midpoint (693 m above the chord, 347 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 33.9 m) clears with margin. The geometric line of sight is obstructed — buried 400 m below terrain at its worst point.

Great circle
33.798, -97.937 → 33.189, -96.452 · 115.8°
Loss budget · 10 GHz
FSPL (free-space) 156.2 dB
Gaseous (O₂ + H₂O) 1.1 dB
Diffraction 113.3 dB
Rain attenuation 0.0 dB
Total path loss 270.6 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 7.1 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 -270.6 dB
RX antenna gain 30.0 dBi
RX power -192.6 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -52.6 dB
Path weather · HRRR average of 9 samples
Temperature
80.3 °F
26.8 °C
Dewpoint
44.2 °F
6.8 °C
T/Td gap
36.1 °F
20.1 °C
Abs. humidity
7.1
g/m³
Pressure
974.0
mb
PWAT
14.0
mm
BL depth
2242.3
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 33.8, -97.9 27.1 °C 6.3 °C 984.2 mb 2305.5 13.7 mm
13% 33.7, -97.8 27.4 °C 6.1 °C 983.1 mb 2318.3 14.0 mm
25% 33.6, -97.6 24.8 °C 8.8 °C 974.0 mb 2197.3 14.3 mm
38% 33.6, -97.4 26.3 °C 8.9 °C 981.1 mb 2101.0 14.5 mm
Midpoint 33.5, -97.2 26.4 °C 8.3 °C 986.2 mb 2113.6 14.2 mm
63% 33.4, -97.0 26.8 °C 7.2 °C 992.2 mb 2249.6 14.1 mm
75% 33.3, -96.8 27.6 °C 5.9 °C 993.6 mb 2289.9 14.3 mm
88% 33.3, -96.6 27.6 °C 4.7 °C 994.3 mb 2315.0 13.5 mm
Destination 33.2, -96.5 27.6 °C 4.8 °C 995.4 mb 2290.7 13.7 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 82 at 05:00 UTC · low 73 at 11:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 75 GOOD
21:00 75 GOOD
22:00 75 GOOD
23:00 75 GOOD
00:00 74 GOOD
01:00 79 GOOD
02:00 77 GOOD
03:00 80 EXCELLENT
04:00 80 EXCELLENT
05:00 82 EXCELLENT
06:00 82 EXCELLENT
07:00 82 EXCELLENT
08:00 81 EXCELLENT
09:00 80 EXCELLENT
10:00 81 EXCELLENT
11:00 73 GOOD
12:00 · now 75 GOOD