Add /path calculator page

LiveView page for analyzing microwave propagation between two points.
Features:
- Source/destination input: callsign (via gridmap.org API) or Maidenhead grid
- Band selector for all 8 microwave bands (10-241 GHz)
- Leaflet map showing path line (reuses ContactMap hook)
- Terrain elevation cross-section (reuses ElevationProfile hook)
- Link summary: distance, bearing, terrain verdict
- Loss budget: FSPL + O2 + H2O + rain + diffraction
- Propagation score with 10-factor breakdown
- Current atmospheric conditions from path-integrated HRRR

New CallsignClient for gridmap.org location lookup.
Navigation links added to main navbar and map control panel.
This commit is contained in:
Graham McIntire 2026-04-07 13:24:58 -05:00
parent 577313a39e
commit 95351a2358
5 changed files with 631 additions and 0 deletions

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@ -0,0 +1,37 @@
defmodule Microwaveprop.Radio.CallsignClient do
@moduledoc "Looks up amateur radio callsign locations via gridmap.org."
@doc """
Fetch location for a callsign. Returns {:ok, %{callsign, gridsquare, lat, lon}} or {:error, reason}.
"""
def locate(callsign) do
url = "https://gridmap.org/locate/#{URI.encode(callsign)}"
case Req.get(url, req_options() ++ [receive_timeout: 10_000]) do
{:ok, %{status: 200, body: %{"latitude" => lat, "longitude" => lon} = body}} when is_number(lat) ->
{:ok,
%{
callsign: body["callsign"] || callsign,
gridsquare: body["gridsquare"],
lat: lat,
lon: lon
}}
{:ok, %{status: 200, body: _}} ->
{:error, "callsign not found"}
{:ok, %{status: 404}} ->
{:error, "callsign not found"}
{:ok, %{status: status}} ->
{:error, "gridmap.org HTTP #{status}"}
{:error, reason} ->
{:error, "gridmap.org failed: #{inspect(reason)}"}
end
end
defp req_options do
Application.get_env(:microwaveprop, :callsign_req_options, [])
end
end

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@ -41,6 +41,7 @@ defmodule MicrowavepropWeb.Layouts do
<a href="/" class="font-semibold">NTMS Propagation Prediction</a>
<nav class="flex gap-2">
<.link navigate="/map" class="btn btn-ghost btn-sm">Map</.link>
<.link navigate="/path" class="btn btn-ghost btn-sm">Path</.link>
<.link navigate="/contacts/map" class="btn btn-ghost btn-sm">Contact Map</.link>
<.link navigate="/contacts" class="btn btn-ghost btn-sm">Contacts</.link>
<.link navigate="/submit" class="btn btn-ghost btn-sm">Submit</.link>

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@ -360,6 +360,9 @@ defmodule MicrowavepropWeb.MapLive do
<%!-- Links --%>
<div class="flex flex-col gap-1 border-t border-base-300 pt-2">
<.link navigate="/path" class="btn btn-xs btn-ghost justify-start">
Path Calculator
</.link>
<.link navigate="/weather" class="btn btn-xs btn-ghost justify-start">
Weather Map
</.link>

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@ -0,0 +1,589 @@
defmodule MicrowavepropWeb.PathLive do
@moduledoc false
use MicrowavepropWeb, :live_view
alias Microwaveprop.Propagation.BandConfig
alias Microwaveprop.Propagation.Scorer
alias Microwaveprop.Radio.CallsignClient
alias Microwaveprop.Radio.Maidenhead
alias Microwaveprop.Terrain.ElevationClient
alias Microwaveprop.Terrain.TerrainAnalysis
alias Microwaveprop.Weather
@band_options [
{"10 GHz", "10000"},
{"24 GHz", "24000"},
{"47 GHz", "47000"},
{"68 GHz", "68000"},
{"76 GHz", "75000"},
{"122 GHz", "122000"},
{"134 GHz", "134000"},
{"241 GHz", "241000"}
]
@impl true
def mount(_params, _session, socket) do
{:ok,
assign(socket,
page_title: "Path Calculator",
band_options: @band_options,
source: "",
destination: "",
band: "10000",
result: nil,
error: nil,
computing: false
)}
end
@impl true
def handle_event("calculate", %{"source" => source, "destination" => dest, "band" => band}, socket) do
socket = assign(socket, source: source, destination: dest, band: band, error: nil, computing: true, result: nil)
send(self(), {:compute_path, source, dest, String.to_integer(band)})
{:noreply, socket}
end
@impl true
def handle_info({:compute_path, source, dest, band_mhz}, socket) do
case compute_path(source, dest, band_mhz) do
{:ok, result} ->
{:noreply, assign(socket, result: result, computing: false)}
{:error, reason} ->
{:noreply, assign(socket, error: reason, computing: false)}
end
end
defp compute_path(source, dest, band_mhz) do
with {:ok, src} <- resolve_location(source),
{:ok, dst} <- resolve_location(dest) do
band_config = BandConfig.get(band_mhz) || BandConfig.get(10_000)
freq_ghz = band_mhz / 1000
dist_km = haversine_km(src.lat, src.lon, dst.lat, dst.lon)
bearing = bearing_deg(src.lat, src.lon, dst.lat, dst.lon)
# Terrain profile
terrain_result =
case ElevationClient.fetch_elevation_profile(src.lat, src.lon, dst.lat, dst.lon, 64, download: true) do
{:ok, profile} ->
analysis = TerrainAnalysis.analyse(profile, dist_km, freq_ghz)
%{profile: profile, analysis: analysis}
{:error, _} ->
nil
end
# HRRR profiles along path
now = DateTime.utc_now()
midlat = (src.lat + dst.lat) / 2
midlon = (src.lon + dst.lon) / 2
hrrr_profiles =
[{src.lat, src.lon}, {midlat, midlon}, {dst.lat, dst.lon}]
|> Enum.map(fn {lat, lon} -> Weather.find_nearest_hrrr(lat, lon, now) end)
|> Enum.reject(&is_nil/1)
# Build conditions and score
{conditions, scoring} = build_scoring(hrrr_profiles, src, now, band_config)
# Loss budget
loss_budget = compute_loss_budget(dist_km, freq_ghz, band_config, terrain_result, conditions)
{:ok,
%{
source: src,
destination: dst,
band_config: band_config,
band_mhz: band_mhz,
freq_ghz: freq_ghz,
dist_km: dist_km,
bearing: bearing,
terrain: terrain_result,
conditions: conditions,
scoring: scoring,
loss_budget: loss_budget,
hrrr_count: length(hrrr_profiles)
}}
end
end
defp resolve_location(input) do
input = String.trim(input)
cond do
input == "" ->
{:error, "Location is required"}
maidenhead?(input) ->
case Maidenhead.to_latlon(input) do
{:ok, {lat, lon}} -> {:ok, %{lat: lat, lon: lon, label: String.upcase(input), type: :grid}}
:error -> {:error, "Invalid grid square: #{input}"}
end
true ->
case CallsignClient.locate(input) do
{:ok, info} ->
{:ok,
%{lat: info.lat, lon: info.lon, label: String.upcase(info.callsign), grid: info.gridsquare, type: :callsign}}
{:error, reason} ->
{:error, "Could not find #{input}: #{reason}"}
end
end
end
defp maidenhead?(input) do
String.length(input) >= 4 and String.length(input) <= 10 and
Regex.match?(~r/^[A-Ra-r]{2}[0-9]{2}/i, input)
end
defp build_scoring([], _src, _now, _band_config), do: {nil, nil}
defp build_scoring(profiles, src, now, band_config) do
temps = profiles |> Enum.map(& &1.surface_temp_c) |> Enum.reject(&is_nil/1)
dewpoints = profiles |> Enum.map(& &1.surface_dewpoint_c) |> Enum.reject(&is_nil/1)
if temps == [] or dewpoints == [] do
{nil, nil}
else
avg_temp_c = Enum.sum(temps) / length(temps)
avg_dewpoint_c = Enum.sum(dewpoints) / length(dewpoints)
pressures = profiles |> Enum.map(& &1.surface_pressure_mb) |> Enum.reject(&is_nil/1)
gradients = profiles |> Enum.map(& &1.min_refractivity_gradient) |> Enum.reject(&is_nil/1)
bl_depths = profiles |> Enum.map(& &1.hpbl_m) |> Enum.reject(&is_nil/1)
pwats = profiles |> Enum.map(& &1.pwat_mm) |> Enum.reject(&is_nil/1)
conditions = %{
abs_humidity: Scorer.absolute_humidity(avg_temp_c, avg_dewpoint_c),
temp_f: Scorer.c_to_f(avg_temp_c),
dewpoint_f: Scorer.c_to_f(avg_dewpoint_c),
temp_c: avg_temp_c,
dewpoint_c: avg_dewpoint_c,
wind_speed_kts: nil,
sky_cover_pct: nil,
utc_hour: now.hour,
utc_minute: now.minute,
month: now.month,
longitude: src.lon,
pressure_mb: if(pressures != [], do: Enum.min(pressures)),
prev_pressure_mb: nil,
rain_rate_mmhr: 0.0,
min_refractivity_gradient: if(gradients != [], do: Enum.min(gradients)),
bl_depth_m: if(bl_depths != [], do: Enum.sum(bl_depths) / length(bl_depths)),
pwat_mm: if(pwats != [], do: Enum.sum(pwats) / length(pwats))
}
scoring = Scorer.composite_score(conditions, band_config)
{conditions, scoring}
end
end
defp compute_loss_budget(dist_km, freq_ghz, band_config, terrain_result, conditions) do
freq_mhz = freq_ghz * 1000
fspl = 20 * :math.log10(max(dist_km, 0.001)) + 20 * :math.log10(freq_mhz) + 32.44
o2_loss = band_config.o2_db_km * dist_km
h2o_coeff = band_config.h2o_coeff
abs_humidity =
if conditions do
conditions.abs_humidity
else
7.5
end
h2o_loss = h2o_coeff * abs_humidity * dist_km
rain_loss =
if conditions && conditions.rain_rate_mmhr > 0 do
gamma = band_config.rain_k * :math.pow(conditions.rain_rate_mmhr, band_config.rain_alpha)
gamma * dist_km
else
0.0
end
diffraction_loss =
if terrain_result do
terrain_result.analysis.diffraction_db
else
0.0
end
total = fspl + o2_loss + h2o_loss + rain_loss + diffraction_loss
%{
fspl: Float.round(fspl, 1),
o2: Float.round(o2_loss, 2),
h2o: Float.round(h2o_loss, 2),
rain: Float.round(rain_loss, 2),
diffraction: Float.round(diffraction_loss, 1),
total: Float.round(total, 1)
}
end
# ── Geo helpers ──
defp haversine_km(lat1, lon1, lat2, lon2) do
r = 6371.0
dlat = deg_to_rad(lat2 - lat1)
dlon = deg_to_rad(lon2 - lon1)
a = :math.sin(dlat / 2) ** 2 + :math.cos(deg_to_rad(lat1)) * :math.cos(deg_to_rad(lat2)) * :math.sin(dlon / 2) ** 2
2 * r * :math.asin(:math.sqrt(a))
end
defp bearing_deg(lat1, lon1, lat2, lon2) do
lat1r = deg_to_rad(lat1)
lat2r = deg_to_rad(lat2)
dlonr = deg_to_rad(lon2 - lon1)
y = :math.sin(dlonr) * :math.cos(lat2r)
x = :math.cos(lat1r) * :math.sin(lat2r) - :math.sin(lat1r) * :math.cos(lat2r) * :math.cos(dlonr)
b = :math.atan2(y, x) * 180 / :math.pi()
Float.round(:math.fmod(b + 360, 360), 1)
end
defp deg_to_rad(d), do: d * :math.pi() / 180
# ── Score tier helpers ──
defp tier_label(score) when score >= 80, do: "EXCELLENT"
defp tier_label(score) when score >= 65, do: "GOOD"
defp tier_label(score) when score >= 50, do: "MARGINAL"
defp tier_label(score) when score >= 33, do: "POOR"
defp tier_label(_), do: "NEGLIGIBLE"
defp tier_color(score) when score >= 80, do: "#00ffa3"
defp tier_color(score) when score >= 65, do: "#7dffd4"
defp tier_color(score) when score >= 50, do: "#ffe566"
defp tier_color(score) when score >= 33, do: "#ff9044"
defp tier_color(_), do: "#ff4f4f"
defp terrain_verdict_class("CLEAR"), do: "badge badge-success"
defp terrain_verdict_class("FRESNEL_MINOR"), do: "badge badge-warning"
defp terrain_verdict_class("FRESNEL_PARTIAL"), do: "badge badge-warning"
defp terrain_verdict_class("BLOCKED"), do: "badge badge-error"
defp terrain_verdict_class(_), do: "badge"
defp format_number(n) when is_float(n), do: :erlang.float_to_binary(n, decimals: 1)
defp format_number(n), do: to_string(n)
# ── Render ──
@impl true
def render(assigns) do
~H"""
<Layouts.app flash={@flash} max_width="max-w-6xl">
<.header>
Path Calculator
<:subtitle>Analyze microwave propagation between two points</:subtitle>
</.header>
<form phx-submit="calculate" class="bg-base-200 rounded-box p-4 mb-6">
<div class="grid grid-cols-1 md:grid-cols-4 gap-4 items-end">
<div class="fieldset">
<label class="label text-sm font-medium">Source (callsign or grid)</label>
<input
type="text"
name="source"
value={@source}
placeholder="W5ISP or EM13sf"
class="input input-bordered w-full"
required
/>
</div>
<div class="fieldset">
<label class="label text-sm font-medium">Destination (callsign or grid)</label>
<input
type="text"
name="destination"
value={@destination}
placeholder="K5TR or EM00cd"
class="input input-bordered w-full"
required
/>
</div>
<div class="fieldset">
<label class="label text-sm font-medium">Band</label>
<select name="band" class="select select-bordered w-full">
<%= for {label, value} <- @band_options do %>
<option value={value} selected={value == @band}>{label}</option>
<% end %>
</select>
</div>
<button type="submit" class="btn btn-primary" disabled={@computing}>
<%= if @computing do %>
<span class="loading loading-spinner loading-sm"></span> Computing...
<% else %>
Calculate
<% end %>
</button>
</div>
</form>
<%= if @error do %>
<div class="alert alert-error mb-6">{@error}</div>
<% end %>
<%= if @result do %>
<.path_results result={@result} />
<% end %>
</Layouts.app>
"""
end
defp path_results(assigns) do
~H"""
<%!-- Map --%>
<div
id="path-map"
phx-hook="ContactMap"
phx-update="ignore"
data-pos1={Jason.encode!(%{lat: @result.source.lat, lon: @result.source.lon})}
data-pos2={Jason.encode!(%{lat: @result.destination.lat, lon: @result.destination.lon})}
data-station1={@result.source.label}
data-station2={@result.destination.label}
class="w-full h-64 md:h-80 rounded-box overflow-hidden mb-4"
>
</div>
<%!-- Terrain profile --%>
<%= if @result.terrain do %>
<div
id="path-elevation"
phx-hook="ElevationProfile"
phx-update="ignore"
data-profile={Jason.encode!(elevation_data(@result))}
class="w-full h-48 md:h-56 rounded-box overflow-hidden mb-6 bg-base-200"
>
</div>
<% end %>
<%!-- Summary cards --%>
<div class="grid grid-cols-1 md:grid-cols-3 gap-4 mb-6">
<%!-- Link Summary --%>
<div class="bg-base-200 rounded-box p-4">
<div class="text-xs opacity-60 mb-2">Link Summary</div>
<div class="space-y-1 text-sm">
<div class="flex justify-between">
<span>Distance</span>
<span class="font-mono">{format_number(@result.dist_km)} km</span>
</div>
<div class="flex justify-between">
<span>Bearing</span>
<span class="font-mono">{format_number(@result.bearing)}&deg;</span>
</div>
<div class="flex justify-between">
<span>Band</span>
<span class="font-mono">{@result.band_config.label}</span>
</div>
<%= if @result.terrain do %>
<div class="flex justify-between">
<span>Terrain</span>
<span class={terrain_verdict_class(@result.terrain.analysis.verdict)}>
{@result.terrain.analysis.verdict}
</span>
</div>
<% end %>
<div class="flex justify-between">
<span>HRRR Profiles</span>
<span class="font-mono">{@result.hrrr_count} / 3</span>
</div>
</div>
</div>
<%!-- Loss Budget --%>
<div class="bg-base-200 rounded-box p-4">
<div class="text-xs opacity-60 mb-2">Loss Budget</div>
<div class="space-y-1 text-sm">
<div class="flex justify-between">
<span>Free Space</span>
<span class="font-mono">{@result.loss_budget.fspl} dB</span>
</div>
<div class="flex justify-between">
<span>O&#8322; Absorption</span>
<span class="font-mono">{@result.loss_budget.o2} dB</span>
</div>
<div class="flex justify-between">
<span>H&#8322;O Absorption</span>
<span class="font-mono">{@result.loss_budget.h2o} dB</span>
</div>
<%= if @result.loss_budget.rain > 0 do %>
<div class="flex justify-between">
<span>Rain</span>
<span class="font-mono">{@result.loss_budget.rain} dB</span>
</div>
<% end %>
<%= if @result.loss_budget.diffraction > 0 do %>
<div class="flex justify-between">
<span>Diffraction</span>
<span class="font-mono">{@result.loss_budget.diffraction} dB</span>
</div>
<% end %>
<div class="divider my-1"></div>
<div class="flex justify-between font-bold">
<span>Total Path Loss</span>
<span class="font-mono">{@result.loss_budget.total} dB</span>
</div>
</div>
</div>
<%!-- Propagation Score --%>
<div class="bg-base-200 rounded-box p-4">
<div class="text-xs opacity-60 mb-2">Propagation Score</div>
<%= if @result.scoring do %>
<div class="text-center mb-3">
<span
class="text-4xl font-bold"
style={"color: #{tier_color(@result.scoring.score)}"}
>
{@result.scoring.score}
</span>
<span class="text-sm opacity-60"> / 100</span>
<div
class="text-sm font-semibold mt-1"
style={"color: #{tier_color(@result.scoring.score)}"}
>
{tier_label(@result.scoring.score)}
</div>
</div>
<% else %>
<div class="text-center text-sm opacity-60 py-4">
No HRRR data available for current conditions
</div>
<% end %>
</div>
</div>
<%!-- Factor breakdown --%>
<%= if @result.scoring do %>
<div class="bg-base-200 rounded-box p-4 mb-6">
<div class="text-xs opacity-60 mb-3">Propagation Factors (current conditions)</div>
<.factor_table scoring={@result.scoring} />
</div>
<% end %>
<%!-- Atmospheric conditions --%>
<%= if @result.conditions do %>
<div class="bg-base-200 rounded-box p-4 mb-6">
<div class="text-xs opacity-60 mb-3">Path Atmospheric Conditions</div>
<div class="grid grid-cols-2 md:grid-cols-4 gap-3 text-sm">
<div>
<span class="opacity-60">Temperature</span>
<div class="font-mono">{format_number(@result.conditions.temp_c)}&deg;C</div>
</div>
<div>
<span class="opacity-60">Dewpoint</span>
<div class="font-mono">{format_number(@result.conditions.dewpoint_c)}&deg;C</div>
</div>
<div>
<span class="opacity-60">T-Td Depression</span>
<div class="font-mono">
{format_number(@result.conditions.temp_c - @result.conditions.dewpoint_c)}&deg;C
</div>
</div>
<div>
<span class="opacity-60">Pressure</span>
<div class="font-mono">{format_number(@result.conditions.pressure_mb || 0)} mb</div>
</div>
<div>
<span class="opacity-60">PWAT</span>
<div class="font-mono">{format_number(@result.conditions.pwat_mm || 0)} mm</div>
</div>
<div>
<span class="opacity-60">BL Depth</span>
<div class="font-mono">{format_number(@result.conditions.bl_depth_m || 0)} m</div>
</div>
<div>
<span class="opacity-60">Refractivity Gradient</span>
<div class="font-mono">
{format_number(@result.conditions.min_refractivity_gradient || 0)} N/km
</div>
</div>
<div>
<span class="opacity-60">Abs Humidity</span>
<div class="font-mono">{format_number(@result.conditions.abs_humidity)} g/m&sup3;</div>
</div>
</div>
</div>
<% end %>
"""
end
defp factor_table(assigns) do
weights = BandConfig.weights()
rows =
assigns.scoring.factors
|> Enum.map(fn {key, score} ->
weight = Map.get(weights, key, 0)
%{
name: factor_name(key),
score: score,
weight: round(weight * 100),
contribution: Float.round(score * weight, 1)
}
end)
|> Enum.sort_by(& &1.contribution, :desc)
assigns = assign(assigns, :rows, rows)
~H"""
<table class="table table-sm">
<thead>
<tr>
<th>Factor</th>
<th class="text-right">Score</th>
<th class="text-right">Weight</th>
<th class="text-right">Contribution</th>
</tr>
</thead>
<tbody>
<%= for row <- @rows do %>
<tr>
<td>{row.name}</td>
<td class="text-right font-mono">{row.score}</td>
<td class="text-right font-mono opacity-60">{row.weight}%</td>
<td class="text-right font-mono font-bold">{row.contribution}</td>
</tr>
<% end %>
</tbody>
</table>
"""
end
defp factor_name(:humidity), do: "Humidity"
defp factor_name(:time_of_day), do: "Time of Day"
defp factor_name(:td_depression), do: "T-Td Depression"
defp factor_name(:refractivity), do: "Refractivity"
defp factor_name(:sky), do: "Sky Cover"
defp factor_name(:season), do: "Season"
defp factor_name(:wind), do: "Wind"
defp factor_name(:rain), do: "Rain"
defp factor_name(:pwat), do: "PWAT"
defp factor_name(:pressure), do: "Pressure"
defp elevation_data(result) do
points =
Enum.map(result.terrain.analysis.points, fn p ->
%{
dist_km: p.dist_km,
elev_m: p.elev,
beam_m: p[:beam],
fresnel_top: if(p[:beam] && p[:r1], do: p.beam + p.r1),
fresnel_bottom: if(p[:beam] && p[:r1], do: p.beam - p.r1)
}
end)
%{
points: points,
freq_mhz: result.band_mhz,
dist_km: result.dist_km,
verdict: result.terrain.analysis.verdict,
ducts: []
}
end
end

View file

@ -36,6 +36,7 @@ defmodule MicrowavepropWeb.Router do
live "/contacts", ContactLive.Index
live "/contacts/map", ContactMapLive
live "/contacts/:id", ContactLive.Show
live "/path", PathLive
live "/algo", AlgoLive
live "/backfill", BackfillLive