Skip to content
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

33.1, -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 20:00z · 9/9 path points
Distance
188.3
km · 117.0 mi
Bearing
36.9°
true · rev 216.9°
Terrain
BLOCKED
126.8 dB diffraction
Propagation
71/100
GOOD
Margin
-80.6
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 volume348 m AGL at the midpoint (1043 m above the chord, 522 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 24.3 m) clears with margin. The geometric line of sight is obstructed — buried 506 m below terrain at its worst point.

Great circle
31.773, -97.831 → 33.12, -96.615 · 36.9°
Loss budget · 24 GHz
FSPL (free-space) 165.5 dB
Gaseous (O₂ + H₂O) 6.3 dB
Diffraction 126.8 dB
Rain attenuation 0.0 dB
Total path loss 298.6 dB
Gas rate 0.0333 dB/km · H₂O 0.0020 dB/km/g · O₂ 0.0200 dB/km
Path abs. humidity avg 6.6 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 -298.6 dB
RX antenna gain 30.0 dBi
RX power -220.6 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -80.6 dB
Path weather · HRRR average of 9 samples
Temperature
80.3 °F
26.8 °C
Dewpoint
42.3 °F
5.7 °C
T/Td gap
38.0 °F
21.1 °C
Abs. humidity
6.6
g/m³
Pressure
977.0
mb
PWAT
13.6
mm
BL depth
2240.1
m AGL
Refrac. gradient
0
N/km
Propagation factors · 24 GHz 71/100
Rain
100 14%
Humidity
63 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, -97.4 26.4 °C 6.3 °C 991.7 mb 2123.7 12.7 mm
Midpoint 32.4, -97.2 26.9 °C 4.9 °C 990.3 mb 2316.4 12.4 mm
63% 32.6, -97.1 27.4 °C 5.0 °C 994.6 mb 2352.4 12.7 mm
75% 32.8, -96.9 28.5 °C 3.8 °C 997.9 mb 2366.4 13.4 mm
88% 33.0, -96.8 27.6 °C 5.0 °C 993.2 mb 2412.1 15.4 mm
Destination 33.1, -96.6 28.2 °C 3.9 °C 994.1 mb 2377.9 13.9 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 75 at 21:00 UTC · low 62 at 11:00 UTC
Hour-by-hour propagation score for this path — the series plotted above.
Hour UTC Score Rating
20:00 74 GOOD
21:00 75 GOOD
22:00 70 GOOD
23:00 74 GOOD
00:00 71 GOOD
01:00 74 GOOD
02:00 69 GOOD
03:00 71 GOOD
04:00 70 GOOD
05:00 73 GOOD
06:00 69 GOOD
07:00 73 GOOD
08:00 73 GOOD
09:00 73 GOOD
10:00 73 GOOD
11:00 62 MARGINAL
12:00 · now 63 MARGINAL