@type t() :: %Sidereon.GNSS.RTK.ArcState{
  ambiguity_prior_sigma_m: float(),
  baseline_m: vec3(),
  epoch_count: non_neg_integer(),
  fixed_cycles: %{required(String.t()) => integer()},
  fixed_m: %{required(String.t()) => float()},
  information: [[float()]],
  references: %{required(String.t()) => String.t()},
  sd_ambiguities_m:
    %{required(String.t()) => float()} | [{String.t(), float()}],
  sd_ambiguity_ids: [String.t()],
  version: non_neg_integer()
}

@type vec3() :: {float(), float(), float()}