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.

33.5, -97.9 · EM13bn · 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
124.1
km · 77.1 mi
Bearing
112.1°
true · rev 292.1°
Terrain
BLOCKED
99.9 dB diffraction
Propagation
69/100
GOOD
Margin
-37.1
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 volume151 m AGL at the midpoint (453 m above the chord, 227 m above the 4/3 horizon), so its Fresnel zone (F₁ ≈ 30.5 m) clears with margin. The geometric line of sight is obstructed — buried 222 m below terrain at its worst point.

Great circle
33.546, -97.85 → 33.12, -96.615 · 112.1°
Loss budget · 10 GHz
FSPL (free-space) 154.3 dB
Gaseous (O₂ + H₂O) 0.9 dB
Diffraction 99.9 dB
Rain attenuation 0.0 dB
Total path loss 255.1 dB
Gas rate 0.0070 dB/km · H₂O 0.0000 dB/km/g · O₂ 0.0070 dB/km
Path abs. humidity avg 7.2 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 -255.1 dB
RX antenna gain 30.0 dBi
RX power -177.1 dBm
Sensitivity (CW, 500 Hz) -141.0 dBm
Margin -37.1 dB
Path weather · HRRR average of 9 samples
Temperature
79.9 °F
26.6 °C
Dewpoint
44.4 °F
6.9 °C
T/Td gap
35.6 °F
19.8 °C
Abs. humidity
7.2
g/m³
Pressure
979.3
mb
PWAT
14.5
mm
BL depth
2247.5
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 33.5, -97.9 27.1 °C 5.0 °C 979.9 mb 2290.1 13.0 mm
13% 33.5, -97.7 26.3 °C 5.9 °C 979.3 mb 2248.8 13.3 mm
25% 33.4, -97.5 25.4 °C 7.3 °C 982.6 mb 2056.9 12.5 mm
38% 33.4, -97.4 24.7 °C 9.8 °C 983.6 mb 2071.5 15.0 mm
Midpoint 33.3, -97.2 26.4 °C 8.3 °C 989.9 mb 2184.3 14.2 mm
63% 33.3, -97.1 26.7 °C 6.5 °C 993.2 mb 2227.0 13.2 mm
75% 33.2, -96.9 27.7 °C 6.0 °C 995.5 mb 2360.1 15.5 mm
88% 33.2, -96.8 27.0 °C 6.8 °C 992.1 mb 2289.3 16.2 mm
Destination 33.1, -96.6 28.4 °C 6.3 °C 993.9 mb 2499.5 17.5 mm
Midpoint vertical profile
18-hour forecast · this path · 10 GHz → steady
Propagation score for this path over the next 18 hours. 0 25 50 75 100
Peak 84 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 76 GOOD
21:00 75 GOOD
22:00 75 GOOD
23:00 75 GOOD
00:00 74 GOOD
01:00 78 GOOD
02:00 77 GOOD
03:00 82 EXCELLENT
04:00 80 EXCELLENT
05:00 84 EXCELLENT
06:00 83 EXCELLENT
07:00 81 EXCELLENT
08:00 80 EXCELLENT
09:00 81 EXCELLENT
10:00 82 EXCELLENT
11:00 73 GOOD
12:00 75 GOOD
13:00 · now 77 GOOD