120 likes | 238 Views
NCAR Aviation Facility Processing Software. Current System Architecture. In Flight. On The Ground. Control & Recording (discWin). Raw Data. Raw Data. Image Data. De-spike Time Shift FIR filtering (HRT) Derived parameters. Processor. QC. Processor. WINDS Display. WINDS Display.
E N D
Current System Architecture In Flight On The Ground Control& Recording (discWin) RawData RawData Image Data • De-spike • Time Shift • FIR filtering (HRT) • Derived parameters Processor QC Processor WINDS Display WINDS Display WINDS Display netCDFfile Serial ASCII Feed Iridium to ground • Real-time • Web-based • Post-flight Display & Analysis To onboard users
System Specifications • OS: Redhat Linux 9.0. • Language: C. 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. • LRT (1hz) takes about 2 minutes to process. • HRT (25hz) takes about 15 minutes to process.
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
Read Data Check For Time Gap Decode Raw Data Apply Analog Cals De-spike Time Shift Average to 1hz FIR filter (rate change) Compute Derived Output High Rate (25hz) Real time Buffer/Data Flow Processing Flow (1 of 3 main loops) RawData Low Rate, 1hz ADSdata (raw) SampleRateData AveragedData HighRateData netCDF & SQL
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)
….. • In use for 11 years on 45 projects. • PMS-2D processing recently added. • Future • Finish error checking • Second-pass processing.