PathLive: ionosphere readout panel for VHF paths

Closes the GIRO → SporadicE → display loop. When a 144 or 440 MHz path
is calculated, PathLive looks up the nearest polled ionosonde's latest
foEs via Ionosphere.nearest_foes/3, runs SporadicE.es_score for the
actual (band, distance) pair, and renders a panel showing:

* Live foEs / foF2 / station-code / timestamp
* Computed single-hop Es MUF for this exact path length
* 0-100 Es score for the selected band
* Human-readable interpretation ("strong opening", "tropo only",
  "out of single-hop window", etc.)

Panel only appears for 144/440 (Es isn't relevant on microwave) and
only when the nearest station has data within the last 2 hours — if
ionosonde data is stale or missing, the panel is omitted entirely
rather than shown with misleading values.

Does not touch the grid scorer on /map — a grid cell has no intrinsic
path length, so Es scoring there is conceptually muddy. PathLive is
the right home for path-specific predictions.

lib/microwaveprop_web/live/path_live.ex

@@ -4,9 +4,11 @@ defmodule MicrowavepropWeb.PathLive do
 
   import MicrowavepropWeb.Components.SkewTChart
 
+  alias Microwaveprop.Ionosphere
   alias Microwaveprop.Propagation
   alias Microwaveprop.Propagation.BandConfig
   alias Microwaveprop.Propagation.Scorer
+  alias Microwaveprop.Propagation.SporadicE
   alias Microwaveprop.Radio.CallsignClient
   alias Microwaveprop.Radio.Maidenhead
   alias Microwaveprop.Terrain.ElevationClient
@@ -270,6 +272,10 @@ defmodule MicrowavepropWeb.PathLive do
       # 18-hour forecast from propagation grid (midpoint of path)
       forecast = Propagation.point_forecast(band_mhz, midlat, midlon)
 
+      # Ionosphere readout at the midpoint (sporadic-E potential).
+      # Only relevant for VHF where Es propagation is physically possible.
+      ionosphere = build_ionosphere_readout(band_mhz, midlat, midlon, dist_km)
+
       {:ok,
        %{
          source: src,
@@ -287,11 +293,39 @@ defmodule MicrowavepropWeb.PathLive do
          power_budget: power_budget,
          forecast: forecast,
          hrrr_count: length(hrrr_profiles),
-         hrrr_points: hrrr_points
+         hrrr_points: hrrr_points,
+         ionosphere: ionosphere
        }}
     end
   end
 
+  # Returns nil when there's no usable readout, or a map describing the
+  # nearest ionosonde's current foEs + the computed Es score for
+  # (band, distance). Only VHF bands get the readout.
+  defp build_ionosphere_readout(band_mhz, midlat, midlon, dist_km) when band_mhz in [144, 440] do
+    case Ionosphere.nearest_foes(midlat, midlon) do
+      {:ok, obs} ->
+        es_score = SporadicE.es_score(obs.fo_es_mhz, band_mhz, dist_km)
+        muf = SporadicE.single_hop_muf(obs.fo_es_mhz, dist_km)
+
+        %{
+          station_code: obs.station_code,
+          valid_time: obs.valid_time,
+          fo_es_mhz: obs.fo_es_mhz,
+          fo_f2_mhz: obs.fo_f2_mhz,
+          mufd_mhz: obs.mufd_mhz,
+          es_score: es_score,
+          es_muf_mhz: muf,
+          es_in_range?: dist_km >= 500 and dist_km <= 2500
+        }
+
+      {:error, _reason} ->
+        nil
+    end
+  end
+
+  defp build_ionosphere_readout(_band_mhz, _lat, _lon, _dist), do: nil
+
   defp resolve_location(input) do
     input = String.trim(input)
 
@@ -883,6 +917,11 @@ defmodule MicrowavepropWeb.PathLive do
       <.atmospheric_profile hrrr_points={@result.hrrr_points} />
     <% end %>
 
+    <%!-- Ionosphere (GIRO sporadic-E readout) --%>
+    <%= if @result.ionosphere do %>
+      <.ionosphere_readout readout={@result.ionosphere} band_mhz={@result.band_mhz} />
+    <% end %>
+
     <%!-- 18-Hour Forecast --%>
     <%= if @result.forecast != [] do %>
       <.forecast_chart forecast={@result.forecast} band_config={@result.band_config} />
@@ -983,6 +1022,73 @@ defmodule MicrowavepropWeb.PathLive do
     """
   end
 
+  attr :readout, :map, required: true
+  attr :band_mhz, :integer, required: true
+
+  defp ionosphere_readout(assigns) do
+    ~H"""
+    <div class="bg-base-200 rounded-box p-4 mb-6">
+      <div class="flex items-center justify-between mb-2">
+        <div class="text-xs opacity-60">Ionosphere &middot; Sporadic-E Potential</div>
+        <div class="text-[10px] opacity-50">
+          {@readout.station_code} · {Calendar.strftime(@readout.valid_time, "%Y-%m-%d %H:%M UTC")}
+        </div>
+      </div>
+
+      <div class="grid grid-cols-2 md:grid-cols-4 gap-3 text-sm">
+        <div>
+          <div class="text-[10px] uppercase tracking-wider opacity-60">foEs</div>
+          <div class="font-bold text-lg">
+            {format_foes(@readout.fo_es_mhz)}
+            <span class="text-xs font-normal opacity-60">MHz</span>
+          </div>
+        </div>
+        <div>
+          <div class="text-[10px] uppercase tracking-wider opacity-60">foF2</div>
+          <div class="font-bold text-lg">
+            {format_foes(@readout.fo_f2_mhz)}
+            <span class="text-xs font-normal opacity-60">MHz</span>
+          </div>
+        </div>
+        <div>
+          <div class="text-[10px] uppercase tracking-wider opacity-60">Es MUF (path)</div>
+          <div class="font-bold text-lg">
+            {format_foes(@readout.es_muf_mhz)}
+            <span class="text-xs font-normal opacity-60">MHz</span>
+          </div>
+        </div>
+        <div>
+          <div class="text-[10px] uppercase tracking-wider opacity-60">
+            Es Score ({@band_mhz} MHz)
+          </div>
+          <div class="font-bold text-lg" style={"color: #{tier_color(@readout.es_score)}"}>
+            {@readout.es_score}
+          </div>
+        </div>
+      </div>
+
+      <div class="text-[11px] opacity-70 mt-3 leading-snug">
+        <%= cond do %>
+          <% not @readout.es_in_range? -> %>
+            Path length is outside the single-hop Es window (500–2500 km) — tropo only for this distance.
+          <% @readout.es_score == 0 -> %>
+            No sporadic-E propagation predicted: the layer is not ionised enough at {@readout.station_code} to reflect {@band_mhz} MHz at this path length.
+          <% @readout.es_score >= 80 -> %>
+            Strong sporadic-E opening predicted — the Es MUF exceeds {@band_mhz} MHz for this path length.
+          <% @readout.es_score >= 50 -> %>
+            Marginal sporadic-E opening: MUF is near the band threshold, worth monitoring.
+          <% true -> %>
+            Weak sporadic-E fringe — the layer is ionised but not quite enough to reliably reflect {@band_mhz} MHz.
+        <% end %>
+      </div>
+    </div>
+    """
+  end
+
+  defp format_foes(nil), do: "—"
+  defp format_foes(v) when is_float(v), do: :erlang.float_to_binary(v, decimals: 1)
+  defp format_foes(v), do: to_string(v)
+
   attr :forecast, :list, required: true
   attr :band_config, :map, required: true
 

test/microwaveprop_web/live/path_live_test.exs

@@ -3,6 +3,7 @@ defmodule MicrowavepropWeb.PathLiveTest do
 
   import Phoenix.LiveViewTest
 
+  alias Microwaveprop.Ionosphere
   alias Microwaveprop.Propagation
   alias Microwaveprop.Propagation.ScoreCache
   alias Microwaveprop.Terrain.ElevationClient
@@ -65,4 +66,59 @@ defmodule MicrowavepropWeb.PathLiveTest do
       refute refreshed =~ ~r/Best:.*?<span[^>]*>\s*30\s*<\/span>/s
     end
   end
+
+  describe "ionosphere panel" do
+    setup do
+      Req.Test.stub(ElevationClient, fn conn ->
+        params = Plug.Conn.fetch_query_params(conn).query_params
+        lat_count = params["latitude"] |> String.split(",") |> length()
+        Req.Test.json(conn, %{"elevation" => List.duplicate(200.0, lat_count)})
+      end)
+
+      :ok
+    end
+
+    test "renders Es panel with live foEs and score when nearest station has fresh data", %{conn: conn} do
+      # Seed Millstone Hill with an extreme-Es observation (foEs = 18 MHz).
+      recent = DateTime.truncate(DateTime.utc_now(), :second)
+
+      {:ok, _} =
+        Ionosphere.upsert_observations("MHJ45", [
+          %{valid_time: recent, fo_es_mhz: 18.0, fo_f2_mhz: 9.0, mufd_mhz: 28.0}
+        ])
+
+      # 52.6N, -71.5W to 32.6N, -71.5W → 2220 km pure N-S across
+      # Millstone Hill's latitude (midpoint 42.6N).
+      {:ok, lv, _} = live(conn, ~p"/path?source=52.6,-71.5&destination=32.6,-71.5&band=144")
+
+      html = render(lv)
+      assert html =~ "Ionosphere"
+      assert html =~ "MHJ45"
+      assert html =~ "foEs"
+      assert html =~ ~r/18\.\d/
+    end
+
+    test "renders 'tropo only' notice when path is outside the single-hop Es window", %{conn: conn} do
+      recent = DateTime.truncate(DateTime.utc_now(), :second)
+
+      {:ok, _} =
+        Ionosphere.upsert_observations("MHJ45", [
+          %{valid_time: recent, fo_es_mhz: 18.0, fo_f2_mhz: 9.0, mufd_mhz: 28.0}
+        ])
+
+      # ~100 km path — way under the 500 km Es minimum.
+      {:ok, lv, _} = live(conn, ~p"/path?source=42.6,-71.5&destination=43.5,-71.5&band=144")
+
+      html = render(lv)
+      assert html =~ "Ionosphere"
+      assert html =~ ~r/out of range|not applicable|tropo only/i
+    end
+
+    test "omits the Es panel entirely when nearest ionosonde has no recent data", %{conn: conn} do
+      {:ok, lv, _} = live(conn, ~p"/path?source=42.6,-71.5&destination=32.6,-71.5&band=144")
+
+      html = render(lv)
+      refute html =~ "Ionosphere"
+    end
+  end
 end