Subject: [SLR-Mail] No. 880: JASON Tracking From: Carey Noll > ******************************************************************************** SLR Electronic Mail 2002-01-11 09:09:00 UTC Message No. 880 ******************************************************************************** Author: Carey Noll Subject: JASON Tracking Dear Colleagues: As most of you are already aware, JASON, the follow-on to the TOPEX/Poseidon Mission, was launched on December 7th, 2001. The final stages of maneuvering JASON into the tandem orbit with TOPEX/Poseidon are underway. In its final orbit, JASON will follow TOPEX/Poseidon by about one minute in time. The orbit maneuver should be completed today, January 10th, 2002 and predictions will be forthcoming shortly thereafter. It is very important that we track both TOPEX/Poseidon and JASON intensively. Since these satellites will be so close, we are requesting that stations track full passes of each satellite, but alternate between satellites for every successful pass. (For example, for the first pass, track JASON for a full pass, and then on the next pass, track TOPEX for the full pass.) We may try something more complicated later, but right now it is very important to get as much data as possible. The official SLR tracking starts on Monday, January 14. You should acquire the satellite prior to that date so that you can be up and running smoothly on Monday. Please take note, the retroreflector cross-section on JASON is considerably smaller than that of TOPEX/Poseidon so you may need to make some accommodation in your ranging procedures. JASON is an oceanography mission to monitor global ocean circulation, study the tie between the oceans and atmosphere, improve global climate predictions, and monitor events such as El Niño conditions and ocean eddies. JASON will have GPS tracking. The SLR data will support POD, provide the crucial centering of the orbit relative to the Earth´s center of mass and provide the absolute calibration of the radial orbit error. Important JASON orbit information: Launch: Dec 7, 2001 Altitude: 1336 km Inclination: 66.0 deg Eccentricity: ~0.0 SIC #: 4378 COSPAR #: 0105501 NORAD #: 26997 Npt Bin Size: 15 secs The ILRS priority will be set at four, above TOPEX, but the alternate tracking strategy should be used. Acquisition data will be available as soon as we are notified by CNES that the satellite is in its final orbit. Good luck and best regards, Carey Noll. Secretary, ILRS Central Bureau +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ Ms. Carey Noll Manager, Crustal Dynamics Data Information System (CDDIS) Code 920.1 E-mail: noll@cddisa.gsfc.nasa.gov NASA GSFC Voice: (301) 614-6542 Greenbelt, MD 20771 Fax: (301) 614-5970 USA WWW: http://cddisa.gsfc.nasa.gov/cddis_welcome.html +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+ From: Carey Noll ********************************************************************************