Zou Ziming 1 Ma Wenzhen Li Lei Zhao Hua Wang Chi 1: Center for Space Science and Applied Research Chinese Academy of Sciences Moscow · Oct 11-16, 2010 Overview of the YH-1 Science Data System

OUTLINE –Objectives of YH-1 Science Data System –Infrastructure of YH-1 Science Data System –The Science Data Pipeline of YH-1 Mars Mission –The specification of YH-1 Science Data Products –Data Archiving and How to Access to the Archives 2

1. Objectives of YH-1 Science Data System –Process the down-linked raw data to PDS3-compliant high quality higher level data products –Collect suitable organized and well-documented YH-1 science data products into PDS3-compliant YH-1 science data archives that would be peer-reviewed, make them available and useful to users –Provide online YH-1 science data access to the international planetary science communities –Ensure the long-term preservation of the data products and maintain their usability 3

2. Infrastructure of YH-1 Science Data System 4

Components of YH-1 SDS ComponentFunction Description Raw Data Collecting Collecting L1 raw data from Scientific Operation Center (SOC). Raw Data Pre-processing Picking-up instrument data from L1 raw data, and generating L2 edited instrument data after time-ordering, duplicates and errors removing, etc. High Level Data Products Processing and Inverting Processing and inverting science data from L2 to higher levels through calibrating, resampling, derivation, etc., generating PDS3-compliant science data products. YH-1 Scientific DatabaseData management and storage. PDS Products Validating Validating the grammar and contents of data files and PDS Labels. Data Products Archiving Archiving science data into data sets with necessary ancillary data compliant with PDS3 for long-term preservation. Science Data DistributingProviding online science data access service to the international planetary science communities via the Internet. 5

Hardware platform of YH-1 SDS 6

3. Science Data Pipeline 7

Overview of YH-1 science data level Data levelIdentifierDescription for processing level Level 1 (Raw) L1 Raw packaged data downlink from YH-1 satellite received at different ground stations, with science and engineering data embedded. Level 2 (Edited) L2 Instrument science data at full resolution, converted from binary to decimal (e.g., voltages, counts), time-ordered, splicing all data of once downlink from different ground stations together, with duplicates and errors removed, have been divided or merged based on Earth Day (UTC 00:00:00-23:59:59) or event. Level 3 (Calibrated) L3 Level 2 data that have been located in space and have been transformed (e.g., calibrated, rearranged) in a reversible manner and packaged with needed ancillary and auxiliary data. Level 4 (Resampled) L4 Irreversibly transformed (e.g., resampled, remapped, calibrated) values of the instrument measurements. Level 5 (Derived) L5 Geophysical parameters mapped onto uniform space-time grids, commensurate with instrument location, pointing, and sampling, and may have additional corrections applied. 8

4. Science Data Products Specification Instrument / Measurement Level 1 (Raw) Level 2 (Edited) Level 3 (Calibrated) Level 4 (Resampled) Level 5 (Derived) Flux-gate Magnetometer Sensor A √ √√ √ Sensor B √√ Plasma Package Electron Analyzer √√ Ion Energy and Mass Analyzer I √√ Ion Energy and Mass Analyzer II √√ Optical Imager Imager 1 √√ Imager 2 √√ Occultation Experiment Sat-Sat Occultation Receiver √√ Sat-Ground Occultation Experiment √√ Raw data: downlink instruments raw data, sat-ground occultation experiment raw data. Data Products: 18 kinds of science data products (from L2 to L5). 9

Probing objective of flux-gate magnetometer Magnetic field of Martian space environment Data products –L2 data: Corresponding voltage as sampled by the instrument (two probes), obtained after conversion of original binary code to a decimal corresponding voltage value. –L3 data: Space magnetic field strength of each probe (sensor A and sensor B), obtained after converting the corresponding voltage to actual voltage value, temperature correction and transforming the actual voltage data into magnetic field strength. –L5 data: Space magnetic field strength at the spacecraft position, obtained by eliminating the platform remanence by fusing the data from the two probes. Data products of flux-gate magnetometer 10

Probing objective of plasma package Plasma of Martian space Data products –L2 data: Counts as sampled by the instrument (three probes), obtained after conversion of original binary code to a decimal counts value. –L3 data: Electron flux and ion flux, obtained by converting the counts value to flux value. Data products of plasma package 11

Probing objective of optical imager Sandstorm and Mars surface imaging 200m finest resolution, FOV 38X38 o, 20X20 o. Data products –L2 data: Grayscale images in bmp format, 8 bit per pixel. –L4 data: RGB color images in bmp format, 24 bit per pixel. Data products of optical imager 12

Probing objective of occultation experiment  Sat-sat occultation: Martian midnight ionosphere  Sat-ground occultation: Martian atmosphere and daytime ionosphere Data products  Sat-sat occultation: –L2 data: Phase and amplitude. –L5 data: Electron density (Martian ionospheric parameters ).  Sat-ground occultation: –L5 data: Electron density, atmospheric temperature, atmospheric density and atmospheric pressure (Martian ionospheric and atmospheric parameters). Data products of occultation experiment 13

An example of optical imager data archive structure 5. Data Archiving 14

5. How to access the Science Archives Quick search area, input the condition to retrieve the data set Click on payload names, users can see its products list 15

A simulated data set list example, user can directly browser or download the specific data files and its labels, catalog files, calibration files, geometry files or other documents. 16

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