Feat/minimum elev service grid

sharc/antenna/antenna_s1528.py

@@ -175,12 +175,18 @@ def __init__(self, param: ParametersAntennaS1528):
         # the system design
         self.l_s = param.antenna_l_s
 
+        # far-out side-lobe level [dBi]
+        if param.far_out_side_lobe is None:
+            self.l_f = 0
+        else:
+            self.l_f = param.far_out_side_lobe
+
         # for elliptical antennas, this is the ratio major axis/minor axis
         # we assume circular antennas, so z = 1
-        self.z = 1
-
-        # far-out side-lobe level [dBi]
-        self.l_f = 0
+        if param.major_minor_axis_ratio is None:
+            self.z = 1
+        else:
+            self.z = param.major_minor_axis_ratio
 
         # back-lobe level
         self.l_b = np.maximum(
@@ -190,19 +196,22 @@ def __init__(self, param: ParametersAntennaS1528):
         # one-half the 3 dB beamwidth in the plane of interest
         self.psi_b = param.antenna_3_dB_bw / 2
 
-        if self.l_s == -15:
-            self.a = 2.58 * math.sqrt(1 - 1.4 * math.log10(self.z))
-        elif self.l_s == -20:
-            self.a = 2.58 * math.sqrt(1 - 1.0 * math.log10(self.z))
-        elif self.l_s == -25:
-            self.a = 2.58 * math.sqrt(1 - 0.6 * math.log10(self.z))
-        elif self.l_s == -30:
-            self.a = 2.58 * math.sqrt(1 - 0.4 * math.log10(self.z))
+        if math.isclose(self.z, 1.0):
+            self.a = 2.58
         else:
-            sys.stderr.write(
-                "ERROR\nInvalid AntennaS1528 L_s parameter: " + str(self.l_s),
-            )
-            sys.exit(1)
+            if self.l_s == -15:
+                self.a = 2.58 * math.sqrt(1 - 1.4 * math.log10(self.z))
+            elif self.l_s == -20:
+                self.a = 2.58 * math.sqrt(1 - 1.0 * math.log10(self.z))
+            elif self.l_s == -25:
+                self.a = 2.58 * math.sqrt(1 - 0.6 * math.log10(self.z))
+            elif self.l_s == -30:
+                self.a = 2.58 * math.sqrt(1 - 0.4 * math.log10(self.z))
+            else:
+                sys.stderr.write(
+                    f"ERROR\nInvalid AntennaS1528 L_s parameter {self.l_s} for z={self.z}"
+                )
+                sys.exit(1)
 
         self.b = 6.32
         self.alpha = 1.5

sharc/parameters/antenna/parameters_antenna_s1528.py

@@ -37,6 +37,14 @@ class ParametersAntennaS1528(ParametersBase):
     l_r: float = None
     l_t: float = None
 
+    # Recommends 1.2 only
+    # For elliptical antennas, this is the ratio major axis/minor axis
+    # we assume circular antennas, so z = 1
+    major_minor_axis_ratio: float = None
+
+    # Far-out side-lobe level
+    far_out_side_lobe: float = None
+
     def load_parameters_from_file(self, config_file: str):
         """Load the parameters from file an run a sanity check.
 

sharc/parameters/imt/parameters_grid.py

@@ -339,6 +339,9 @@ class ParametersSatelliteWithServiceGrid(ParametersTerrestrialGrid):
 
     beam_radius: float = None
 
+    # [deg]
+    minimum_service_angle: float = 5.0
+
     def validate(self, ctx):
         """Validates instance parameters.
         Parameters
@@ -353,6 +356,9 @@ def validate(self, ctx):
             )
         self.cell_radius = self.beam_radius
 
+        if self.minimum_service_angle < 0. or self.minimum_service_angle > 90:
+            raise ValueError(f"{ctx}.minimum_service_angle should be in [0, 90]")
+
         if not isinstance(
                 self.eligible_sats_margin_from_border,
                 float) and not isinstance(

sharc/propagation/atmosphere.py

@@ -385,6 +385,9 @@ def get_reference_atmosphere_p835(
         """
 
         h_km = altitude / 1000
+        season = season.lower()
+        if season not in ['winter', 'summer']:
+            raise ValueError(f"Invalid season name {season}.")
 
         if latitude <= 22:
             # low latitude

tests/parameters/parameters_for_testing.yaml

@@ -264,6 +264,7 @@ imt:
                     # if positive, makes border smaller by x km
                     # if negative, makes border bigger by x km
                     eligible_sats_margin_from_border: -2.1
+                    minimum_service_angle: 10.1
             sat_is_active_if:
                 # for a satellite to be active, it needs to respect ALL conditions
                 conditions:
@@ -998,6 +999,9 @@ single_space_station:
             # Antenna diameter [m]
             # if no diameter is passed, a diameter will be assumed according to document
             diameter: 2.12
+        itu_r_s_1528:
+            major_minor_axis_ratio: 1.0
+            far_out_side_lobe: -25
     ###########################################################################
     # Selected channel model
     channel_model: "P619"
@@ -1096,6 +1100,7 @@ mss_d2d:
             # if positive, makes border smaller by x km
             # if negative, makes border bigger by x km
             eligible_sats_margin_from_border: -2.1
+            minimum_service_angle: 12.1
     sat_is_active_if:
         # for a satellite to be active, it needs to respect ALL conditions
         conditions:

tests/parameters/test_parameters.py

@@ -313,6 +313,8 @@ def test_parameters_imt(self):
             0.11)
         self.assertEqual(
             self.parameters.imt.topology.mss_dc.beam_positioning.service_grid.eligible_sats_margin_from_border, -2.1)
+        self.assertEqual(
+            self.parameters.imt.topology.mss_dc.beam_positioning.service_grid.minimum_service_angle, 10.1)
         self.assertEqual(len(
             self.parameters.imt.topology.mss_dc.beam_positioning.service_grid.grid_in_zone.from_countries.country_names), 2)
         self.assertEqual(
@@ -709,6 +711,8 @@ def test_parametes_mss_d2d(self):
             0.11)
         self.assertEqual(
             self.parameters.mss_d2d.beam_positioning.service_grid.eligible_sats_margin_from_border, -2.1)
+        self.assertEqual(
+            self.parameters.mss_d2d.beam_positioning.service_grid.minimum_service_angle, 12.1)
         self.assertEqual(
             len(self.parameters.mss_d2d.beam_positioning.service_grid.grid_in_zone.from_countries.country_names), 2)
         self.assertEqual(
@@ -871,6 +875,20 @@ def test_parameters_single_space_station(self):
             self.parameters.single_space_station.antenna.gain,
         )
 
+        self.assertEqual(
+            self.parameters.single_space_station.antenna.itu_r_s_1528.antenna_gain,
+            self.parameters.single_space_station.antenna.gain,
+        )
+        self.assertEqual(
+            self.parameters.single_space_station.antenna.itu_r_s_1528.major_minor_axis_ratio,
+            1.0
+        )
+
+        self.assertEqual(
+            self.parameters.single_space_station.antenna.itu_r_s_1528.far_out_side_lobe,
+            -25
+        )
+
         self.assertEqual(
             self.parameters.single_space_station.param_p619.earth_station_alt_m,
             self.parameters.single_space_station.geometry.es_altitude,

tests/test_antenna_s1528.py

@@ -23,6 +23,8 @@ def setUp(self):
         param.antenna_gain = 39
         param.antenna_pattern = "ITU-R S.1528-0"
         param.antenna_3_dB_bw = 2
+        param.major_minor_axis_ratio = 1
+        param.far_out_side_lobe = 0
 
         param.antenna_l_s = -20
         self.antenna20 = AntennaS1528(param)

tests/test_topology_imt_mss_dc.py

@@ -6,6 +6,7 @@
 from sharc.station_manager import StationManager
 from sharc.parameters.parameters_orbit import ParametersOrbit
 from sharc.support.sharc_geom import CoordinateSystem, lla2ecef
+from sharc.satellite.utils.sat_utils import calc_elevation
 
 
 class TestTopologyImtMssDc(unittest.TestCase):
@@ -156,6 +157,51 @@ def test_visible_satellites(self):
         # oblateness
         npt.assert_array_less(min_elevation_angle, xy_plane_elevations)
 
+    def test_minimum_service_angle(self):
+        """Test minimum visibility angle for service grid service."""
+        orbit = ParametersOrbit(
+            n_planes=1,
+            sats_per_plane=1,
+            phasing_deg=3.9,
+            long_asc_deg=18.0,
+            inclination_deg=54.5,
+            perigee_alt_km=525,
+            apogee_alt_km=525,
+        )
+        self.coordinate_system.set_reference(0.0, 0.0, 0)
+
+        self.params.orbits = [orbit]
+        self.params.beam_positioning.type = "SERVICE_GRID"
+        self.params.beam_positioning.service_grid.grid_in_zone.type = "CIRCLE"
+        self.params.beam_positioning.service_grid.grid_in_zone.circle.center_lat = 0.0
+        self.params.beam_positioning.service_grid.grid_in_zone.circle.center_lon = 0.0
+        self.params.beam_positioning.service_grid.grid_in_zone.circle.radius_km = 10 * 111.0
+        self.params.validate("")
+
+        self.imt_mss_dc_topology = TopologyImtMssDc(
+            self.params, self.coordinate_system)
+
+        n_previous_selected = np.inf
+        for a in [5, 50, 80]:
+            self.imt_mss_dc_topology.orbit_params.beam_positioning.service_grid.minimum_service_angle = a
+            self.imt_mss_dc_topology.calculate_coordinates(
+                random_number_gen=np.random.RandomState(8))
+
+            lon_lat_grid = self.params.beam_positioning.service_grid.lon_lat_grid
+            elev_from_bs = calc_elevation(
+                lon_lat_grid[1],
+                self.imt_mss_dc_topology.lat[0],
+                lon_lat_grid[0],
+                self.imt_mss_dc_topology.lon[0],
+                sat_height=self.imt_mss_dc_topology.height[0],
+                es_height=0.0,
+            )
+            n_selected = np.sum(elev_from_bs >= a)
+            self.assertLess(n_selected, n_previous_selected)
+            self.assertLess(n_selected, len(elev_from_bs))
+            self.assertEqual(n_selected, self.imt_mss_dc_topology.num_base_stations)
+            n_previous_selected = n_selected
+
 
 if __name__ == '__main__':
     unittest.main()