Function encode_json 

pub fn encode_json(omm: &Omm) -> String

Encode an Omm as a CCSDS/CelesTrak OMM JSON object.

Numeric element values are emitted as JSON numbers (round-tripping the exact f64), strings as JSON strings, and the epoch as an ISO-8601 string, so parsing the output reproduces the same Omm. Requires the json feature.