Next: RSOG Pre-Observation Products
RadioAstron Mission Element Overview
The main mission elements (ME) are:
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Before proceeding further, the nomenclature used within the handbook will be briefly described.
An observation is a single continuous event, usually lasting for several hours, when SRT antenna is pointed to the chosen radio sources and all scientific and service on-board equipmet operate in accordance with the program stored in the SC on-board memory.
An experiment is one or more observations of a single source at a single frequency within a single proposal. Experiment codes of five characters are used in naming GRT related files. For experiments with multiple epochs (i.e. multiple observations) the six character observation code is sometimes used.
A tracking pass is a single continuous occasion in which the two-way link is established between a single GTS and the space radio telescope (SRT). An observation consists of one or more tracking passes.
A control session is a telemetry (TM)communication with the SpaceCraft (SC) in order to transmit defenite sequence of commands which will be memorised in the on-board memory, to receive TM-information from the SC, and to conduct orbit measurements in P and C bands. The duration of control session is from 2 to 4 hours.
Ku-band science data telemetry is the real-time link between the GTS and the SRT. The nominal downlink frequency is 15.062 GHz.
X-band phase transfer is the real-time up-down link between the GTS and SRT. The up-link nominal frequency is 7.125 GHz, and downlink is at 8.47 GHz.
C-band telemetry is conducted between the Control Station (CS) and the SRT. Commanding is done at the uplink frequency of 5.008 GHz, and housekeeping telemetry (and range and range-rate monitoring) at the down-link frequency of 5.884 GHz.
P-band telemetry is conducted between the Control Station (CS) and the SRT. Commanding is done at the uplink frequency of 0.770 GHz, and housekeeping telemetry (and range and range-rate monitoring) at the down-link frequency of 0.930 GHz.
A self-hold mode is such a state of the SC, when only necessary equipment is switched on to provide correct functioning of the system with minimum power consumption. In this mode the SC is always ready to receive commands from CS.
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Overview of this document
An overview of the data products and interfaces is given in the table on the following page. The 'X' in the file extension column refers to the designated code for the relevant tracking station or ground radio telescope. These are described in more detail later in the document.
|Origin / Data Product||File Ext.||User|
|Long-Term Experiment Schedule||gst||ME|
|Observation Summary File||osf||Corr (GTS?)|
|GRT Schedules||crd, skd, drg'||GRT|
|Merged Correlator Input Log||vs||Corr|
|Calibration and Flag files||tsm||Corr, PI|
|(Phase Calibration Data)||-||-|
|RSOG Status Reports||svg||ME|
|Space Radio Telescope Schedule||srs||GTS|
|Constraints to SC Operations||cns||RSOG|
|Control Session Files||spr||CS|
|Executed Sequence of Events||xse||NAV|
|Telemetry Prognosis Files||tpf||GOCG|
|SRT Status Report||svg||RSOG|
|Long-Term Predicted Orbit||opr||RSOG|
|Orbit for Scheduling||opr||RSOG|
|Orbit for Tracking||opr||GTS|
|MBC OD Results||onp||CS|
|(JPL MMNAV Orbit)||bsp||Corr|
|Navigation Status Reports||?||RSOG|
|Telemetry Header File (THF)||ktX||RSOG|
|Time Corrections File (TCF)||kcX||Corr (RSOG?)|
|Time Components File||tcX||Corr (RSOG?)|
|Data Processing Log (to VLBA)||klX||Corr|
|Data Processing Log (to S2)||ksX||Corr|
|Station Performance Log (SPL)||kpX||RSOG|
|JPL/DOTS Monitor Data File (MDF)||kmX||RSOG|
|GTS Status Reports||stX||RSOG|
|GRT Log File||X||Corr|
|GRT Calibration Data||X||PI, Corr|
|GRT Clock Offset Data||X||Corr|
|GRT Gain Curves||--||PI, Corr|
|VLBI Tape Management||-||ME|
|VLBI Tapes||-||GRT, GTS|
|NRT Fringe Detector Results||-||RSOG (Corr?)|
|Correlator Status Reports||sco||RSOG|