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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.

33.4, -96.4 · EM13ti · 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
20.6
km · 12.8 mi
Bearing
193.3°
true · rev 13.3°
Terrain
BLOCKED
14.0 dB diffraction
Propagation
69/100
GOOD
Margin
+65.2
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 volume ≈ 4 m AGL at the midpoint (12 m above the chord, 6 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 12.4 m) clears with margin. The geometric line of sight is obstructed — buried 2 m below terrain at its worst point.

Great circle
33.369, -96.401 → 33.189, -96.452 · 193.3°
Loss budget · 10 GHz
FSPL (free-space) 138.7 dB
Gaseous (O₂ + H₂O) 0.1 dB
Diffraction 14.0 dB
Rain attenuation 0.0 dB
Total path loss 152.8 dB
Gas rate 0.0068 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 15.0 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 -152.8 dB
RX antenna gain 30.0 dBi
RX power -74.8 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin 65.2 dB
Path weather · HRRR average of 9 samples
Temperature
67.1 °F
19.5 °C
Dewpoint
63.8 °F
17.7 °C
T/Td gap
3.3 °F
1.8 °C
Abs. humidity
15.0
g/m³
Pressure
994.0
mb
PWAT
41.2
mm
BL depth
572.1
m AGL
Refrac. gradient
-58.9
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 33.4, -96.4 19.4 °C 17.7 °C 994.0 mb -57.0 629.9 41.7 mm —
13% 33.3, -96.4 19.4 °C 17.7 °C 994.0 mb -57.0 629.9 41.7 mm —
25% 33.3, -96.4 19.4 °C 17.7 °C 994.0 mb -57.0 629.9 41.7 mm —
38% 33.3, -96.4 18.9 °C 17.4 °C 998.8 mb -54.9 486.3 40.6 mm —
Midpoint 33.3, -96.4 18.9 °C 17.4 °C 998.8 mb -54.9 486.3 40.6 mm —
63% 33.3, -96.4 18.9 °C 17.4 °C 998.8 mb -54.9 486.3 40.6 mm —
75% 33.2, -96.4 20.1 °C 17.9 °C 997.2 mb -58.9 600.2 41.5 mm —
88% 33.2, -96.4 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 74 at 12:00 UTC · low 60 at 21:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
21:00 60 MARGINAL
22:00 63 MARGINAL
23:00 67 GOOD
00:00 66 GOOD
01:00 64 MARGINAL
02:00 62 MARGINAL
03:00 65 GOOD
04:00 68 GOOD
05:00 67 GOOD
06:00 72 GOOD
07:00 68 GOOD
08:00 72 GOOD
09:00 71 GOOD
10:00 73 GOOD
11:00 72 GOOD
12:00 74 GOOD
13:00 · now 74 GOOD