VEX-V-VRA-1-2-3-EXT2-0341

Data Set Overview The Venus Express (VEX) Radio Science (VeRa) Data Archive is a timeordered collection of raw and partially processed data collected during the Venus Express Mission. This is a Occultation measurement covering the time 20100511T04:50:21.050 to 20100511T06:14:59.949. This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Routine Operations phase of the Venus Express (VEX) mission using ground facilities of the European Space Agency (ESA) and/or the NASA Deep Space Network (DSN). VeRa radio occultation observations start shortly before the occultation ingress, when the VEX spacecraft moves behind the planetary disk as seen from the Earth and stop shortly after the occultation egress, when the probe emerges from behind the planet. VeRa occultation data usually cover three recording phases: the occultation ingress (1), the time when the spacecraft is occulted by the planet (2) and the occultation egress (3). The different observation phases can be distinguished by regarding the AGC data, which records the strength of the received signal. In phase (1) and (3) the AGC level is high compared to phase (2). In Phase (2) still a signal may be received at the groundstation due to the strong bending of the radio waves in the dense atmosphere. The strength of the signal is significantly reduced and weakens further the deeper the radio waves penetrate the atmosphere until the groundstation may be unable to lock. Therefore, the beginning of phase (2) is recognized at first order by a sharp drop of the AGC down to 95 dB and lower and ends with a sharp rise in the AGC data back to the former AGC level. For the derivation of higher science products it is recommended to divide the level 2 data into an ingress and an egress part and to process these data seperatetly. This is a radio occultation measurement of the Venusian atmospher truncated!, Please se [truncated!, Please see actual data for full text]