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NCAR Aviation Facility ADS II Overview. Chris Webster, National Center for Atmospheric Research. Overall Theme. 1) Data Acquisition - ADS (Aircraft Data System) - DSM (Data Sampling Module). 3) Data Processing - nimbus processor. 4) Display - WINDS (current program)
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NCAR Aviation FacilityADS II Overview Chris Webster, National Center for Atmospheric Research
Overall Theme 1) Data Acquisition - ADS (Aircraft Data System) - DSM (Data Sampling Module) 3) Data Processing - nimbus processor 4) Display - WINDS (current program) - aeros (new program) 2) Data Recording - discWin - Raw Data / ADS file - Removable disk
VME Chasis • 12 card cage • Modular power supply • vxWorks RTOS • Each box can sample: • 64 Analog channels up to 10K samples • per second (sps) • 64 bits of Digital and/or counter • 8 Serial ports, RS-232 and RS-422 • 3 PMS-1D probes • 2 PMS-2D probes • ARINC 429 • Synchro
Network topology Iridium data-net display-net DataServer Linux PC DSM Display DSM TimeServer IRIG & NTP Display DSM self-recordinginstrument DSM
System Architecture; Data Flow Onboard Data Server Transmit to ground via iridium DSM Data Logger (discWin) User instruments Serial Feed DSM Display (WINDS) Processor (nimbus) Raw Data (ADS file) Inputs - Analog - Digital - Serial Display (WINDS) Shared Memory Data-net Display-net Data Acquisition and Recording Data Processing and Display
Current System Architecture On The Ground RawData • De-spike • Time Shift • FIR filtering (HRT) • Derived parameters Processor netCDFfile • Real-time • Web-based • Post-flight Display & Analysis
System Specifications • OS: Redhat Linux 9.0 and later. • Language: All of our code is C and/or C++. • GUI: Motif, tied to Unix. New developments in Qt (KDE), which is portable to MS-Win, Mac, Unix. • Typical flight is 8-9 hours with 300-375 variables • 60-80 Analog channels. • 120-130 raw block data (PMS, GPS, IRS, etc). • 120-160 derived variables.
Processor Features • Low Rate (1hz), High Rate (25hz), Sample Rate, Real-Time. • De-spike; remove spikes up to 1 second in duration. • Time shift up to plus or minus 1 second. • FIR rate-change filter (HRT processing). • Mask out of bad data. • Quality/Error checking (in development) • Spike detection • Flat line detection • Out of bounds/range detection
Output file – netCDF • Hardware architecture independent. • Self describing (meta-data). • Supports multi-rate data (e.g. ATX @ 25hz, LAT @ 5hz, PMS @ 10hz, etc). • Fortran, C, C++, and Java language API’s. • Interfaces: Matlab, IDL, Python, Perl & Tcl/Tk. • OpenDAP allows network reads via http. • http://www.unidata.ucar.edu/packages/netcdf • NCAR “Conventions” for aircraft data registered with Unidata. • Used by NCAR, University of Wyoming and NOAA.
NCAR netCDF multi-raterecord layout Dimension 1 is the record dimension, 1 record per second 1hz 5hz 1hz 25hz 1hz 1hz, vector16 10hz vector 16 1hz Dimension 2 Sub samples Dimension 3 Vector Data (PMS1D)