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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.

31.8, -97.8 · EM11cs · 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
203.8
km · 126.6 mi
Bearing
39.0°
true · rev 219.0°
Terrain
BLOCKED
129.2 dB diffraction
Propagation
70/100
GOOD
Margin
-84.3
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 volume407 m AGL at the midpoint (1222 m above the chord, 611 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 25.2 m) clears with margin. The geometric line of sight is obstructed — buried 572 m below terrain at its worst point.

Great circle
31.773, -97.831 → 33.189, -96.452 · 39.0°
Loss budget · 24 GHz
FSPL (free-space) 166.2 dB
Gaseous (O₂ + H₂O) 6.9 dB
Diffraction 129.2 dB
Rain attenuation 0.0 dB
Total path loss 302.3 dB
Gas rate 0.0340 dB/km · H₂O 0.0020 dB/km/g · O₂ 0.0200 dB/km
Path abs. humidity avg 7.0 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 -302.3 dB
RX antenna gain 30.0 dBi
RX power -224.3 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -84.3 dB
Path weather · HRRR average of 9 samples
Temperature
80.1 °F
26.7 °C
Dewpoint
43.6 °F
6.4 °C
T/Td gap
36.5 °F
20.3 °C
Abs. humidity
7.0
g/m³
Pressure
977.0
mb
PWAT
13.7
mm
BL depth
2221.4
m AGL
Refrac. gradient
0
N/km
Propagation factors · 24 GHz 70/100
Rain
100 14%
Humidity
59 13%
PWAT
80 11%
Season
47 11%
T-Td Depression
96 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 31.8, -97.8 24.5 °C 7.2 °C 977.0 mb 1981.0 12.8 mm
13% 31.9, -97.7 25.8 °C 7.5 °C 991.0 mb 2098.3 14.6 mm
25% 32.1, -97.5 26.3 °C 8.1 °C 997.0 mb 2132.5 14.4 mm
38% 32.3, -97.3 26.4 °C 6.3 °C 991.7 mb 2123.7 12.7 mm
Midpoint 32.5, -97.1 26.4 °C 6.2 °C 995.8 mb 2290.9 12.1 mm
63% 32.7, -97.0 27.8 °C 5.4 °C 998.2 mb 2291.4 12.6 mm
75% 32.8, -96.8 28.6 °C 4.4 °C 998.6 mb 2409.0 14.4 mm
88% 33.0, -96.6 26.9 °C 8.9 °C 997.3 mb 2285.5 16.9 mm
Destination 33.2, -96.5 27.8 °C 4.1 °C 995.4 mb 2379.9 13.3 mm
Midpoint vertical profile
17-hour forecast · this path · 24 GHz → steady
Propagation score for this path over the next 17 hours. 0 25 50 75 100
Peak 73 at 03:00 UTC · low 61 at 11:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 72 GOOD
21:00 72 GOOD
22:00 68 GOOD
23:00 68 GOOD
00:00 64 MARGINAL
01:00 69 GOOD
02:00 63 MARGINAL
03:00 73 GOOD
04:00 68 GOOD
05:00 72 GOOD
06:00 66 GOOD
07:00 68 GOOD
08:00 71 GOOD
09:00 69 GOOD
10:00 69 GOOD
11:00 61 MARGINAL
12:00 · now 62 MARGINAL