# `Sidereon.GNSS.Constellation.Record`
[🔗](https://github.com/neilberkman/sidereon-ex/blob/main/lib/sidereon/gnss/constellation.ex#L62)

A normalized GNSS satellite identity record.

`active?` means the satellite is present in the base source used to build the
catalog. `usable?` is an advisory health/status flag; for GPS it is `true`
unless a merged NAVCEN row has an active NANU that marks the PRN unusable or
decommissioned. The `source` map preserves source-specific provenance under
`:celestrak`, `:navcen`, and `:navcen_conflict`.

`fdma_channel` is the GLONASS FDMA L1/L2 frequency-channel number `k`
(`-7..=6`); it is `nil` for the CDMA constellations (GPS, Galileo, BeiDou,
QZSS). It is the one identity datum not present in any OMM feed; the core
resolves it from the orbital slot via the published IGS/MCC slot-channel
table (`glonass_fdma_channel/1`).

# `t`

```elixir
@type t() :: %Sidereon.GNSS.Constellation.Record{
  active?: boolean(),
  fdma_channel: integer() | nil,
  norad_id: pos_integer(),
  prn: pos_integer(),
  source: map(),
  sp3_id: String.t(),
  svn: pos_integer() | nil,
  system: Sidereon.GNSS.Constellation.system(),
  usable?: boolean()
}
```

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*Consult [api-reference.md](api-reference.md) for complete listing*