Module tle 

Two-Line Element (TLE) format parser and encoder.

TLE is the legacy fixed-width format for satellite orbital elements, designed for 80-column punch cards. This module owns the complete format grammar: ASCII and fixed-width validation, the modulo-10 checksum, the “assumed decimal” exponent codec used for the drag terms, the per-field number formatting, and the two-digit-year pivot. It runs identically regardless of the calling language, so it lives in the core; the sidereon Elixir binding only marshals the epoch between its native DateTime and the (year, day_of_year) pair this module exposes, normalizes input defaults, and maps errors.

The epoch is represented here as a calendar year plus a one-based fractional day-of-year, exactly the two quantities the TLE epoch field encodes. This module owns the TLE two-digit-year pivot and converts that pair into SGP4’s split Julian date when building the format-agnostic element set.

Structs

ChecksumWarning

A reported checksum discrepancy. The format grammar does not reject a line on a bad checksum (it is advisory), so this is surfaced for the host to log.

ParsedTle

The result of parse: the elements plus any advisory checksum warnings.

TleElements

Parsed TLE orbital elements in canonical astrodynamic units.

Enums

TleError

Failure modes of parse. Messages mirror the historical reference strings.

Constants

MAX_NUMERIC_TLE_CATALOG_NUMBER

Highest catalog number that remains a five-digit numeric TLE field.

MAX_TLE_CATALOG_NUMBER

Highest catalog number that can be represented in a legacy TLE field.

Functions

decode_catalog_number

Decode a five-character TLE catalog field into its numeric catalog id.

encode

Encode TleElements as the two 69-character TLE lines (with checksums).

encode_catalog_number

Encode a numeric catalog id into its five-character TLE catalog field.

parse

Parse a two-line element set into TleElements.