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FPGA SPECTROMETER COMMISSIONING. Spectrometer description How it will be used Where we are at. What needs to be done More info: Pdev device: http://www.naic.edu/~phil/hardware/pdev/pdev.html This talk : http://www.naic.edu/~phil/talks/talks.html. Description.. what we bought/made.
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FPGA SPECTROMETER COMMISSIONING Spectrometer description How it will be used Where we are at. What needs to be done More info: Pdev device: http://www.naic.edu/~phil/hardware/pdev/pdev.html This talk : http://www.naic.edu/~phil/talks/talks.html AUSAC Meeting · March 17&18, 2008
Description.. what we bought/made • 20 spectrometer boxes purchased from jeff mock • 1 box can process 1 beam of alfa. • 14 boxes allows for 2 simultaneous alfa experiments. • 2 boxes for aeronomy, planetary radar • 16 fileservers (each with 4 Tbytes of disc). • IF mixer chassis IF to base band (I,Q) (dana) AUSAC Meeting · March 17&18, 2008
Description.. 1 box • 2 paths each handling 170 MHz Bandwidth • A/D.. 12 bit 170 MHz I Q samplers • Digital mixer. • Digital low pass filter (decimation 2..1024) • Optional time domain data: 4,8,16 bits • Polyphase filter bank..16 to 8192 channels. • I, polA/B, full stokes power computation. • Sum spectra. Output 32,16,8 bit spectral data. • Box output I/O rate: 80 Mbytes/sec (both paths) AUSAC Meeting · March 17&18, 2008
How it will be used • Alfa: covers 1225-1525 MHz x 7 beams • Galfacts: galaxy full stokes • 65Mb/sec * 7 = 450 Mb/sec. • Palfa search: Upgrade 100 to 300 MHz BW. • 32Mb/sec*7= 225 Mb/sec. • Aeronomy: IF sampling, time domain data • 32,20,10,.. bandwidths. 32 MHz Bw gets plasma line in 1 band • Sampling synced to transmitter pulses and echo return. • Planetary Radar: IF sampling, time domain data. • 40,20,10,.. Bandwidths with 2,4,8,16 bit samples. • Fir filters for CW, sync filters for ranging. • Digital doppler correction by interpolating, dropping samples. • Single Pixel observations: • Use 7*300 MHz bandwidth to cover up tp 2 GHz bw. AUSAC Meeting · March 17&18, 2008
Where we are at. • Alfa: • Hardware • 14 spectrometer boxes with 7 mixer chassis installed. • 14 file servers installed, 7 in use. • Software: • Acquires data, writes to disc in pdev or fits format. • Using the software to debug alfa/pdev combination. • Aeron: • Test plasma line data taken • Planetary radar • 20 MHz bw data taken on saturns rings. AUSAC Meeting · March 17&18, 2008
What needs to be done. • Hardware/FPGA programming: • Continue dynamic range studies of system • Update mixers to match pdev input levels. • Alfa long recovery time (> secs) from radars killer for galfacts • Take a closer look at birdies generated internally to the boxes. • Fgpa programming (tamara has left) • Debug filters (fir and sync) • Debug digital doppler • Single pixel.. Need to widen the downstairs IF/LO to handle 2 GHz bw. • 14 boxes, > 200 cables is labor intensive to work on. We’ve lost 4 techs in the last year or 2 (cheo rosa,tony noya,jose vives, jesus rios) all with > 35 years experience. Currently no digital techs. AUSAC Meeting · March 17&18, 2008
What needs to be done (software) • Integrate running of spectrometer with GUI. • Fill in all fits header keyword data. • Speed up startup configuration of device. • Test winking cal, blanking. • Automate optimum level setting and configuration for all possible configs. • Pulsar users want psrfits format. This is different from the fits files we are generating. • Analysis software. Continue developing IDL routines to verify the device operation. • Work on system/program documentation (see web site). AUSAC Meeting · March 17&18, 2008
When …. • Shooting for may 2008 for galfacts alfa observing. This will also enable any of the other alfa spectral line surveys to use the device. • Alfa compression may not be solved by then. • Pulsar fits file format will come after galfacts (since palfa is already taking data). • Planetary radar/aeronomy needs FPGA programming and Tamara Hall has left so this is on hold. • 2 GHz single pixel still in the design stages. AUSAC Meeting · March 17&18, 2008