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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, -97.6 · EM13ei · 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
98.5
km · 61.2 mi
Bearing
106.4°
true · rev 286.4°
Terrain
BLOCKED
83.0 dB diffraction
Propagation
70/100
GOOD
Margin
-18.0
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 volume95 m AGL at the midpoint (286 m above the chord, 143 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 27.2 m) clears with margin. The geometric line of sight is obstructed — buried 85 m below terrain at its worst point.

Great circle
33.374, -97.63 → 33.12, -96.615 · 106.4°
Loss budget · 10 GHz
FSPL (free-space) 152.3 dB
Gaseous (O₂ + H₂O) 0.7 dB
Diffraction 83.0 dB
Rain attenuation 0.0 dB
Total path loss 236.0 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 -236.0 dB
RX antenna gain 30.0 dBi
RX power -158.0 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -18.0 dB
Path weather · HRRR average of 9 samples
Temperature
68.7 °F
20.4 °C
Dewpoint
63.8 °F
17.6 °C
T/Td gap
4.9 °F
2.7 °C
Abs. humidity
14.9
g/m³
Pressure
980.1
mb
PWAT
40.8
mm
BL depth
632.9
m AGL
Refrac. gradient
-63.7
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 33.4, -97.6 19.8 °C 17.1 °C 980.1 mb -54.7 776.9 40.5 mm
13% 33.3, -97.5 20.3 °C 17.2 °C 987.0 mb -49.1 815.1 38.8 mm
25% 33.3, -97.4 20.9 °C 17.5 °C 989.2 mb -55.5 639.6 40.6 mm
38% 33.3, -97.2 21.2 °C 17.4 °C 992.9 mb -53.3 648.0 41.1 mm
Midpoint 33.2, -97.1 22.1 °C 17.6 °C 994.1 mb -49.4 687.6 42.0 mm
63% 33.2, -97.0 20.4 °C 18.0 °C 995.5 mb -51.5 636.7 42.0 mm
75% 33.2, -96.9 19.9 °C 18.3 °C 996.2 mb -56.2 569.4 41.7 mm
88% 33.2, -96.7 19.5 °C 17.9 °C 992.5 mb -63.7 466.5 40.1 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 79 at 13:00 UTC · low 62 at 02:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
21:00 67 GOOD
22:00 66 GOOD
23:00 70 GOOD
00:00 66 GOOD
01:00 66 GOOD
02:00 62 MARGINAL
03:00 68 GOOD
04:00 70 GOOD
05:00 67 GOOD
06:00 68 GOOD
07:00 74 GOOD
08:00 70 GOOD
09:00 75 GOOD
10:00 75 GOOD
11:00 75 GOOD
12:00 75 GOOD
13:00 · now 79 GOOD