prop/test/microwaveprop/terrain/viewshed_test.exs
Graham McIntire 5eaa55448e
Add terrain-aware viewshed on map click
Replace generic range circles with actual LOS coverage polygon computed
from SRTM elevation data. Casts 180 rays (every 2 degrees) from the
clicked point, runs Fresnel/diffraction analysis on each, and renders
the reachable area as a Leaflet polygon.

- Viewshed module with haversine forward, terrain sweep, async compute
- Antenna height control (default 8 ft) in map panel
- LiveView start_async/handle_async for non-blocking computation
- Remove signal icon from band selector
2026-03-31 13:06:01 -05:00

110 lines
3.5 KiB
Elixir

defmodule Microwaveprop.Terrain.ViewshedTest do
use ExUnit.Case, async: true
alias Microwaveprop.Terrain.Viewshed
describe "destination_point/4" do
test "north bearing increases latitude, holds longitude" do
{lat, lon} = Viewshed.destination_point(32.0, -97.0, 0, 100.0)
assert_in_delta lat, 32.899, 0.01
assert_in_delta lon, -97.0, 0.01
end
test "east bearing increases longitude, holds latitude" do
{lat, lon} = Viewshed.destination_point(32.0, -97.0, 90, 100.0)
assert_in_delta lat, 32.0, 0.01
assert lon > -97.0
end
test "south bearing decreases latitude" do
{lat, lon} = Viewshed.destination_point(32.0, -97.0, 180, 50.0)
assert lat < 32.0
assert_in_delta lon, -97.0, 0.01
end
test "zero distance returns origin" do
{lat, lon} = Viewshed.destination_point(32.0, -97.0, 45, 0.0)
assert_in_delta lat, 32.0, 0.001
assert_in_delta lon, -97.0, 0.001
end
end
describe "find_reach_km/2" do
test "returns max range when no points are obstructed" do
points = [
%{obstructed: false, dist_km: 0.0},
%{obstructed: false, dist_km: 10.0},
%{obstructed: false, dist_km: 20.0},
%{obstructed: false, dist_km: 30.0},
%{obstructed: false, dist_km: 50.0}
]
assert Viewshed.find_reach_km(points, 50.0) == 50.0
end
test "returns distance of point before first obstruction" do
points = [
%{obstructed: false, dist_km: 0.0},
%{obstructed: false, dist_km: 10.0},
%{obstructed: false, dist_km: 20.0},
%{obstructed: true, dist_km: 30.0},
%{obstructed: false, dist_km: 40.0},
%{obstructed: false, dist_km: 50.0}
]
assert Viewshed.find_reach_km(points, 50.0) == 20.0
end
test "returns first interior point distance when obstruction is at second point" do
points = [
%{obstructed: false, dist_km: 0.0},
%{obstructed: true, dist_km: 5.0},
%{obstructed: false, dist_km: 10.0}
]
# First point is endpoint (excluded), second is first interior and is obstructed
# No clear interior point before it, return minimum
assert Viewshed.find_reach_km(points, 10.0) == 0.0
end
test "ignores endpoint obstruction flags" do
# Endpoints (first/last) are never counted as obstructed by TerrainAnalysis
# but just to be safe, find_reach_km skips them
points = [
%{obstructed: true, dist_km: 0.0},
%{obstructed: false, dist_km: 25.0},
%{obstructed: true, dist_km: 50.0}
]
assert Viewshed.find_reach_km(points, 50.0) == 50.0
end
end
describe "analyse_ray/5" do
test "returns full range for flat terrain with antenna heights" do
profile =
for i <- 0..10 do
f = i / 10
%{lat: 32.9 + f * 0.09, lon: -97.0, d: f, elev: 200.0, dist_km: f * 10.0}
end
result = Viewshed.analyse_ray(profile, 10.0, 10.0, 2.4, 2.4)
assert result.reach_km == 10.0
end
test "detects obstruction and returns reduced reach" do
# Use 10km total so earth bulge is negligible (~0.7m) and
# the 500m peak at index 5 is the only obstruction.
profile =
for i <- 0..10 do
f = i / 10
elev = if i == 5, do: 500.0, else: 200.0
%{lat: 32.9 + f * 0.009, lon: -97.0, d: f, elev: elev, dist_km: f * 10.0}
end
result = Viewshed.analyse_ray(profile, 10.0, 10.0, 2.4, 2.4)
assert result.reach_km < 10.0
assert result.reach_km > 0.0
end
end
end