added bootstrap buildings

api/tests/test_core.py

@@ -3,9 +3,10 @@ from math import isclose
 import pytest
 
 from app.core.antenna import AntennaPattern, gain
-from app.core.diffraction import knife_edge_loss
+from app.core.diffraction import bullington_loss, knife_edge_loss, knife_edge_v
 from app.core.fresnel import earth_bulge, fresnel_radius, wavelength
 from app.core.propagation import fspl
+from app.core.surface import SurfaceProfile, SurfaceSample
 from app.core.vegetation import P833Coefficients, p833_attenuation
 
 
@@ -34,6 +35,66 @@ def test_knife_edge_loss_reference_values(v: float, expected: float) -> None:
     assert isclose(knife_edge_loss(v), expected, abs_tol=0.05)
 
 
+def test_bullington_loss_uses_dominant_equivalent_edge() -> None:
+    profile = SurfaceProfile(
+        distance_m=10_000,
+        samples=[
+            SurfaceSample(
+                i=0,
+                lat=0,
+                lon=0,
+                distance_m=0,
+                ground_m=0,
+                building_m=0,
+                canopy_m=0,
+                surface_m=0,
+            ),
+            SurfaceSample(
+                i=1,
+                lat=0,
+                lon=0,
+                distance_m=5_000,
+                ground_m=20,
+                building_m=0,
+                canopy_m=0,
+                surface_m=20,
+            ),
+            SurfaceSample(
+                i=2,
+                lat=0,
+                lon=0,
+                distance_m=10_000,
+                ground_m=0,
+                building_m=0,
+                canopy_m=0,
+                surface_m=0,
+            ),
+        ],
+    )
+    v = knife_edge_v(20, 5_000, 5_000, 433_000_000)
+
+    assert isclose(bullington_loss(profile, 0, 0, 433_000_000), knife_edge_loss(v))
+
+
+def test_bullington_loss_does_not_sum_every_dem_sample() -> None:
+    samples = [
+        SurfaceSample(
+            i=i,
+            lat=0,
+            lon=0,
+            distance_m=i * 100,
+            ground_m=5 if 20 <= i <= 80 else 0,
+            building_m=0,
+            canopy_m=0,
+            surface_m=5 if 20 <= i <= 80 else 0,
+        )
+        for i in range(101)
+    ]
+    profile = SurfaceProfile(distance_m=10_000, samples=samples)
+
+    assert bullington_loss(profile, 0, 0, 433_000_000) < 30
+
+
 def test_p833_formula_with_supplied_coefficients() -> None:
     attenuation = p833_attenuation(
         depth_m=100,