Packages

sidereon

0.29.2
0.31.2 0.30.0 0.29.2 0.29.1 0.29.0 0.28.1 0.28.0 0.27.1 0.27.0 0.26.1 0.25.0 0.24.0 0.23.0 0.22.0 0.21.0 0.20.0 0.19.1 0.19.0 0.18.0 0.17.0 0.16.1 0.15.0 0.14.0 0.13.0 0.12.0 0.11.1 0.11.0 0.10.1 0.10.0 0.9.2 0.9.1 0.9.0 0.8.0 retired

Satellite toolkit for Elixir with SGP4 propagation, coordinate transforms, GNSS positioning, orbit determination, conjunction assessment, pass prediction, and a Rust NIF backend.

HexDocs

Current section

Files

Jump to
Readme
33 Versions
4 Dependencies
0 Dependants
Files
Activity
sidereon lib sidereon gnss core sampling.ex
Raw

lib/sidereon/gnss/core/sampling.ex 

defmodule Sidereon.GNSS.Core.Sampling do

  @moduledoc false



  alias Sidereon.{Coordinates, Elements, SGP4}

  alias Sidereon.GNSS.Core.Epoch

  alias Sidereon.GNSS.SP3



  def sample_sp3(%SP3{} = sp3, sat_id, t0, t1, cadence_s) do

    steps = Epoch.steps(t0, t1, cadence_s)



    samples =

      steps

      |> Enum.reduce([], fn ep, acc ->

        case SP3.position(sp3, sat_id, ep) do

          {:ok, %{x_m: x, y_m: y, z_m: z}} -> [{ep, {x, y, z}} | acc]

          {:error, _} -> acc

        end

      end)

      |> Enum.reverse()



    {:ok, samples, length(steps)}

  end



  def sample_sgp4(%Elements{} = tle, t0, t1, cadence_s) do

    steps = Epoch.steps(t0, t1, cadence_s)



    samples =

      steps

      |> Enum.reduce([], fn ep, acc ->

        dt = DateTime.from_naive!(Epoch.to_naive!(ep), "Etc/UTC")



        case SGP4.propagate(tle, dt) do

          {:ok, teme} ->

            gcrs = Coordinates.teme_to_gcrs(teme, dt)

            {x_km, y_km, z_km} = Coordinates.gcrs_to_itrs(gcrs, dt)

            [{ep, {x_km * 1000.0, y_km * 1000.0, z_km * 1000.0}} | acc]



          _ ->

            acc

        end

      end)

      |> Enum.reverse()



    {:ok, samples, length(steps)}

  end

end