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Re: Predicted P3D Keps



At 02:55 PM 11/14/00 -0500, you wrote:
>         Can anyone pleased a predicted set of keps for P3D?  I would like to
>attempt to hear the beacon when it is switched on.
Below is the estimated State Vector and Keplerian Elements for
the AMSAT Phase 3D spacecraft.  The vector data was computed from
Arianespace orbital parameters at the time Phase 3D is scheduled
to separate from the Ariane 5 upper stage.  The Keplerian Elements
were computed, in turn, from the vector.

Vector format = 10107
Satellite Name:         Phase 3D
Catalog Number:         93400
Epoch MET:                  0.02983771991
                            0/00:42:57.979 MET
EFG E:                      4321.19714449 km
     F:                     10857.07279003 km
     G:                     -1323.50573459 km
     Edot:                   -3.1484853319 km/s
     Fdot:                    5.7556066452 km/s
     Gdot:                   -0.5488001613 km/s
ndot/2 (drag):              0.00000000771 rev/day^2
nddt/6:                       0.00000E+00 rev/day^3
Bstar:                        1.25668E-05 1/Earth Radii
Elset #:                                1
Rev @ Epoch:                1.52588079822

Launch Window Opens:  2000-NOV-15 / 0107 UTC
Phase 3D separation:  Launch + 0042:57.979

The following Keplerian elements were computed from this vector and
the scheduled date and time of the launch window opening.  Updated
Keplerian elements will be computed from the vector, based on changes
to the scheduled or actual launch time.

Phase 3D
1 93400U          00320.07636550  .00000001  00000-0  12567-4 0    13
2 93400   6.5034 246.6469 7357988 175.9296  13.3886  2.02435417    17

Satellite: Phase 3D
Catalog number: 93400
Epoch time:      00320.07636550
Element set:       1
Inclination:        6.5034 deg
RA of node:       246.6469 deg
Eccentricity:    0.7357988
Arg of perigee:   175.9296 deg
Mean anomaly:      13.3886 deg
Mean motion:    2.02435417 rev/day
Decay rate:    7.71000e-09 rev/day^2
Epoch rev:               1
Checksum:              283

Note that "93400" is a temporary Catalog Number.  A Permanent Catalog
Number and International Designator will be assigned when Phase 3D is
launched.  The satellite name will also be updated with the next
sequential "OSCAR" designator.

These Keplerian elements represent a pre-launch estimate of Phase 3D's
initial orbit.  The orbit will change significantly over the first year
the spacecraft is on orbit.  Updates will be provided for significant
orbital changes.

The Phase 3D launch team will be publishing a similar set of Keplerian
elements.  The data provided by the launch team will be "osculating"
parameters, compatible with AMSAT command station software. The
osculating elements are the exact physical representation of the orbit
as opposed to the "mean" parameters provided in this bulletin.  I
provide these mean elements as they are fully compatible with the NORAD
SGP4/SDP4 orbit propagation algorithms.  Tracking software that uses
the NORAD propagators should use the "mean" Keplerian elements provided
herein for the most accurate result.  Tracking software using non-NORAD
orbit propagation methods should use the "osculating" elements provided
by the Phase 3D launch team.

Ken Ernandes, N2WWD
n2wwd@amsat.org
http://www.mindspring.com/~n2wwd



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