---
title: "Get Kepler Elements By Id"
method: GET
path: "/kep_elements/{cdm_id}"
tags: ["Plot"]
---

# Get Kepler Elements By Id

`GET /kep_elements/{cdm_id}`

Get all Keplerian Elements for a given CDM.

## Path parameters

- `cdm_id` string, required — key or cdm_id of conjunction message

## Query parameters

- `mu` number — Earth gravitational constant. 398600.4418 km^3/s^2 will be used as the default.

## Response `200`

Successful Response

- CDMKepElem
  - `primary` KepElem
    - `system` 'EQUINOCITAL' | 'KEPLERIAN' | 'CARTESIAN'
    - `elem_set` ElemSet
      - `semi_major_axis_km` number, nullable
      - `eccentricity` number, nullable
      - `inclination` number, nullable
      - `true_anomaly` number, nullable
      - `argument_of_periapsis` number, nullable
      - `raan` number, nullable
      - `apogee_km` number, nullable
      - `perigee_km` number, nullable
    - `cov` array[], nullable
      - number[]
  - `secondary` KepElem
    - `system` 'EQUINOCITAL' | 'KEPLERIAN' | 'CARTESIAN'
    - `elem_set` ElemSet
      - `semi_major_axis_km` number, nullable
      - `eccentricity` number, nullable
      - `inclination` number, nullable
      - `true_anomaly` number, nullable
      - `argument_of_periapsis` number, nullable
      - `raan` number, nullable
      - `apogee_km` number, nullable
      - `perigee_km` number, nullable
    - `cov` array[], nullable
      - number[]

## Other responses

- `422` — Validation Error

---

[API](https://skmtc.net/satcat/apis/satcat-service-api.md) · [All operations](https://skmtc.net/satcat/apis/satcat-service-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/satcat/satcat-service-api/versions/afeec2546de3/schema)