Next: RSOG Pre-Observation Products
Previous: Introduction

• Mission Elements
• Nomenclature
• Overview of This Document

Mission Elements

The main mission elements (ME) are:

• The RSOG, based at ASC, which is responsible for the science operation of the RadioAstron Mission.
• The GOCG, based at Lavochkin Association, which is responsible for the operation of the RadioAstron satellite.
• The ground tracking stations (GTSs), located at Pushchino (operated by ASC), Green Bank (GBTS, operated by NRAO), and Goldstone, Tidbinbilla, Madrid (DSN GTS, all three operated by the DSN). The interface for the DSN GTSs is the JPL DOTS team.
• The Control Stations(CS), belonging to Lavochkin Association, located near Evpatoria or/and near Moscow, which are responsible for commanding the RadioAstron spacecraft, housekeeping telemetry and range and range-rate monitoring of the satellite.
• The ground radio telescopes (GRTs), located around the world.
• The navigation groups, located at ASC, MBC and JPL. The interface for the JPL Multimission navigation (MMNAV) group is the JPL DOTS team, although the ASC and JPL navigation groups will bi-laterally exchange various data products during normal operations.
• The Main Ballistic(Navigation) Center (MBC) belonging to Lavochkin Association coordinates preparation and exchange of orbit determination and orbit reconstraction ptoducts.
• The Data Processing Center (DPC) located at ASC is responsible for coordination of data processing. DPC will provide merged SRT log-files for all correlators taking into account executed sequence of events and calibration data.
• The correlators, located at Socorro, Penticton, and Dwingeloo. Near real-time fringe detectors will also be located at Pushchino and Green Bank.
• The Principal Investigators (PI). This group will not be considered in detail in this document - a separate document specifically for PIs is in preparation by the RSOG.

back to top

Nomenclature

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.

back to top

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.