Data Provider Groups | Data Provider Elements
Brouwer-Lyd Mean Short
Mean Elements considering just the short period terms from the Brouwer-Lyddane theory.
Included perturbations are the J2, J3, J4 and J5 zonal harmonics including terms involving J2^2. These elements are not time averages of the osculating values,
but are the results of a specific averaging procedure defined by the theory. In the Brouwer theory, a variation of Delaunay elements are averaged and are therefore the actual mean elements.
Other "mean" elements are derived using of osculating orbit element conversions on the computed mean elements. Mean elements are computed in the selected reference frames
by first transforming the osculating state to the selected frame then applying the mean element conversion.
Available for these objects: Satellite
Type: Time-varying data.
Availability: Reports | Graphs | Dynamic Displays | Strip Charts
Data Provider Groups
Data can be requested in a variety of coordinate systems, where the origin of the coordinate system is the object's central body. The available coordinate systems depend on the object's central body. Nominally, the systems Fixed, Inertial, J2000, TrueOfDate, and MeanOfDate are supported, although some central bodies (notably the Earth and Sun) have more.The following lists the systems available for Earth.
| Name | Description |
|---|---|
| ICRF | International Celestial Reference Frame. The ICRF axes are defined as the inertial (i.e., kinematically non-rotating) axes associated with a general relativity frame centered at the solar system barycenter (often called the BCRF). |
| MeanOfDate | The mean equator mean equinox coordinate system evaluated at the requested time. |
| MeanOfEpoch | The mean equator mean equinox coordinate system evaluated at the epoch of the object. |
| TrueOfDate | The true equator true equinox coordinate system evaluated at the requested time. |
| TrueOfEpoch | The true equator true equinox coordinate system evaluated at the epoch of the object. |
| B1950 | The mean equator mean equinox coordinate system evaluated at the beginning of the Besselian year 1950 (31 December 1949 22:09:46.866 = JD 2433282.4234591). |
| TEMEOfEpoch | The true equator mean equinox coordinate system evaluated at the epoch of the object. |
| TEMEOfDate | The true equator mean equinox coordinate system evaluated at the requested time. |
| AlignmentAtEpoch | The non-rotating coordinate system coincident with the Fixed system evaluated at the object's coordinate reference epoch. |
| J2000 | The mean equator mean equinox coordinate system evaluated at the J2000.0 epoch (2000 January 1.5 TDB = JD 2451545.0 TDB). |
Data Provider Elements
| Name | Dimension | Type | Description |
|---|---|---|---|
| Time | DateFormat | Real Number | Time. |
| Mean Semi-major Axis | DistanceUnit | Real Number | Semi-major axis computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include semi-major axis, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Eccentricity | Unitless | Real Number | Eccentricity computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include eccentricity, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Inclination | AngleUnit | Real Number | Inclination computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include inclination, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean RAAN | LongitudeUnit | Real Number | Right ascension of the ascending node computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include RAAN, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Arg of Perigee | AngleUnit | Real Number | Argument of periapsis computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include argument of periapsis, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Mean Anomaly | AngleUnit | Real Number | Mean anomaly computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include mean Anomaly, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Nodal Period | TimeUnit | Real Number | Mean nodal period computed based on the mean element rates for the specified mean element theory. Nodal period is defined time between consecutive crossings of the ascending node. |
| Mean Arg of Latitude | AngleUnit | Real Number | Argument of latitude computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include argument of latitude, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Longitude of Perigee | LongitudeUnit | Real Number | Longitude of perigee computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include longitude of perigee, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |
| Mean Mean Longitude | LongitudeUnit | Real Number | Mean longitude computed from mean elements associated with the specified mean element theory. If the elements associated with the mean theory do not include mean longitude, it is computed from the elements associated with the mean element theory using normal osculating orbit element conversions. |