Fpga spectrometer commissioning spectrometer description

FPGA SPECTROMETER COMMISSIONING

• Spectrometer description

• How it will be used

• Where we are at.

• What needs to be done

• More info:http://www.naic.edu/~phil/hardware/pdev

Description.. what we bought

• 20 spectrometer boxes purchased from jeff mock … (jeff who??)

• 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)

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.

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 (Tamara)

• 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. (Tamara)

• 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.

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.

• Aeron:

• Test data taken in 32Mhz bw Mode

• Planetary radar

• 20 MHz bw data taken on saturns rings.

What needs to be done.

• Hardware/FPGA programming:

• Resolve radar rfi saturation in PFB butterfly stages. If this is not solved, the lower 170 MHz will be unusable.
• Take a closer look at birdies generated internally to the boxes.
• Debug sync filters for planetary radar (Tamara)
• Debug digital doppler (Tamara).
• Single pixel.. Need to widen the downstairs IF/LO to handle 2 GHz bw.

What needs to be done (software)

• Integrate running of spectrometer with GUI.

• This will take the most time.

• 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).

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.

• Pulsar fits file format will come after galfacts (since palfa is already taking data).

• Planetary radar/aeronomy needs FPGA programming and Tamara Hall is leaving.

• Till she leaves, radar/aeronomy work gets priority.

• 2 GHz single pixel still in the design stages.