@spec mapping(number(), number(), number(), NaiveDateTime.t() | tuple()) ::
  {:ok, %{dry: float(), wet: float()}} | {:error, mapping_error()}

Niell hydrostatic and wet mapping factors at an elevation.

epoch is a NaiveDateTime or {{y, m, d}, {h, min, s}} tuple (the Niell seasonal term needs the day-of-year). Returns {:ok, %{dry: dry, wet: wet}} (dimensionless) or {:error, reason}. Niell mapping rejects elevations below its 3 degree validity bound with {:error, :below_mapping_elevation}.

@spec mapping_detailed(number(), number(), number(), NaiveDateTime.t() | tuple()) ::
  detailed_result(%{dry: float(), wet: float()})

Detailed sibling of mapping/4 that returns complete typed refusals, including field and reason for frame-value and time-model constructor errors.

The legacy mapping function keeps returning its existing error categories.

@spec slant_delay(
  number(),
  number(),
  number(),
  number(),
  map(),
  NaiveDateTime.t() | tuple()
) ::
  {:ok, float()} | {:error, term()}

Full slant tropospheric delay in positive meters.

Composes the Saastamoinen zenith delays with the Niell mapping at the given elevation. epoch sets the seasonal day-of-year. Returns {:ok, delay_m} (positive meters; zero at or below the horizon and outside the height validity range) or {:error, reason}.

@spec slant_delay_detailed(
  number(),
  number(),
  number(),
  number(),
  map(),
  NaiveDateTime.t() | tuple()
) ::
  detailed_result(float())

Detailed sibling of slant_delay/6 that returns complete typed refusals, including field and reason for frame-value and time-model constructor errors.

Successful values and the below-horizon zero retain the legacy behavior.

@spec zenith_delay(number(), number(), map()) ::
  {:ok, %{dry_m: float(), wet_m: float()}} | {:error, term()}

Zenith hydrostatic and wet tropospheric delays from supplied meteorology.

Returns {:ok, %{dry_m: dry, wet_m: wet}} (both positive meters) or {:error, reason}. The hydrostatic delay carries the gravity correction for the receiver latitude and height.

@spec zenith_delay_detailed(number(), number(), map()) ::
  detailed_result(%{dry_m: float(), wet_m: float()})

Detailed sibling of zenith_delay/3 that returns complete typed refusals.

Successful values match zenith_delay/3. Core errors retain their kind, message, and debug detail; frame-value and time-model errors retain their family, message, exact field, and reason. The original zenith_delay/3 continues to return its established error atom.