VEX-V-SW-ASPERA-2-NPD

Data Set Overview: This data set contains data collected by the Neutral Particle Detector (NPD) flown onboard the VENUS EXPRESS satellite during the nominal mission phase. The data are stored in ascending time order with respect to the sequential inflight data acquisition. The data (science and HK) in this archive are in standard PDS format and are both organized into fixedwidth tabular objects, an ASCII format with data store in rows and columns. Mainly 3 types of science data are present, one for each selected operation mode. Depending on the flight operation mode in use, science data records are either a data stream of observations identified by a quadruplet (Pulse Height Distribution, TimeOfFlight, direction and coincidence) and sequentially stored, as appeared in RAW data product files, or particle counters given in counts/accumulation units for BIN and TOF modes. Both of them contains data that are splitted and stored into appropriate data files according to the data acquisition mode and the operating sample size (number of PHD bins) of the instrument, in order to maintain fixed width table structure within each data product. The number of rows within the tables is variable and depends roughly on the number of records contained in the associated telemetry packet. An NPD header, specific to each mode of observations and common to NPD1 and NPD2 sensors, is added before a data collection. Instrument Description: The Neutral Particle Detector (NPD) measures the ENA flux, resolving velocity (in the enregy range 100 eV to 10 keV) and mass (H and O) to help satisfy the following scientific objectives: 1. Determine the instantaneous global distributions of plasma and neutral gas near Venus 2. Energy deposition from the solar wind to the ionosphere NPD consists of two identical pinhole detector cameras, each with a 90 degrees of fieldofview in the intrument azimuth plane truncated!, Please see actual data for full te [truncated!, Please see actual data for full text]