Design Gallery

The CASPER Design Gallery is intended to be a place to share reasonably complete Simulink designs and associated software that take advantage of CASPER libraries. Not all of the designs here are in a 'release' stage, and in fact most are still in the alpha stage of development. However, they can be helpful in serving as a framework or guide for similar designs.

Spectrometers

• Design Name: Kurtosis (SK) Spectrometer -- Model File - Software - Wiki
  
  Design Author(s): Zhiwei Lui
  
  Application: This spectrometer is used in an instrument being developed at the Owens Valley Solar Array, called the Korean Solar Radio Burst Locator (KSRBL). This instrument utilizes four of these 500 MHz bandwidth SK spectrometers in parallel, to achieve a 2 GHz instantaneous bandwidth that is time multiplexed over the entire DC-18 GHz radio frequency range, to study solar bursts.
  
  Description: The unique aspect of the spectrometer is that it accumulates both power and power-squared statistics which are then used to develop a Òspectral kurtosisÓ (SK) estimator as described by Nita et al. (2007, PASP 119, 805). The SK estimator is used offline for real-time detection and excision of RFI embedded in the received signal. The required power and power-squared data are broadcast by the FPGA via fast ethernet and converted to the SK estimator using software implemented in LabVIEW.
  
  Dependencies: This design uses the 7.1 blocks (green blocks).



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• Design Name: 400MHz Dual Spectrometer with 10GbE Readout -- Model File - Software - Wiki
  
  Design Author(s): Peter McMahon
  
  Application: Several observatories are interested in digitizing baseband signals with 400MHz bandwidth, and producing power spectra from this data for pulsar science and RFI monitoring, amongst other uses.
  
  Description: This IBOB-based spectrometer uses a single IADC board to digitize two signals at 800MSa/sec. Typically these two signals will be polarization signals from a single antenna. A polyphase filterbank channelizes each signal into 1024 bins. A power detection stage computes the power of each, and these powers are accumulated. Finally the accumulated values from both polarizations are outputted over a single 10GbE connection.
  
  The wiki page for Parspec contains the latest version of the design, and pre-compiled bitstreams. A comprehensive user guide for the design is also available on the wiki. A technical discussion of the Parspec design is included in Peter's thesis.
  
  Dependencies: This design uses the 7.1 blocks (green blocks), and the GAVRT blocks.



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• Design Name: Leuschner Spectrometer -- Model File - Software - Wiki
  
  Design Author(s): Andrew Siemion
  
  Application: The Leuschner Spectrometer is used for undergraduate student radio astronomy instruction at UC Berkeley in conjunction with a 4.5m dish at Leuschner Observatory in Lafayette, California. Primarily this system is used for 21cm work, but occasionally OH observations are performed as well.
  
  Description: This IBOB-based spectrometer design has been optimized for narrow band, high resolution spectroscopy. Compiled for a sampling rate of 96 Msamp/sec, three of four parallel times samples are dropped to yield a 12 MHz bandwidth. A 16384 channel PFB is performed, followed by 64 bits/channel vector accumulation of only the 8192 negative frequencies. A selectable 32 bits/channel of each accumulated spectrum is written to shared memory for output over 100Mbit ethernet. In the complete system, the sky frequency is mixed down to a 150MHz IF, passed through a 150/10 bandpass filter and the 12 MHz region 144-156 MHz aliases down to baseband.
  
  Dependencies: This design uses legacy (pink) blocks.



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• Design Name: Pocket Spectrometer v307d -- Model File - Software - Wiki
  
  Design Author(s): Daniel Chapman
  
  Application: This version of the pocket spectrometer was built as a general purpose instrument for many applications, and as a reference design for other spectrometers. This design served as the basis for the MARS Spectrometer, which was eventually taped out as an ASIC using the Berkeley Wireless Research Center INSECTA Toolflow.
  
  Description: This IBOB-based spectrometer design has been optimized for wide band spectroscopy. Compiled for a sampling rate of 500 Msamp/sec, this design utilizes a single ADC in interleaved mode to yield a bandwidth of 500 MHz. No digital down conversion is performed, giving a band between DC -> 500 MHz. A 1024 channel PFB feeds a unique vector accumulator design, for eventual output via 100Mbit ethernet.
  
  Dependencies: This design uses legacy (pink) blocks.
  
  



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• Design Name: The Fly's Eye Spectrometer -- Model File - Software - Wiki
  
  Design Author(s): Peter McMahon, Andrew Siemion and Aaron Parsons
  
  Application: This spectrometer is used to look for energetic dispersed radio transients using the Allen Telescope Array.
  
  Description: This 4-input, 128 channel IBOB-based spectrometer design has been optimized for fast readout. Compiled for a sampling rate of 840 Msamp/sec, this design utilizes two ADC boards to process a total of 4 signal paths. Digital down conversion selects a band from about 105 to 315 MHz (when clocked at 840 MHz), channelization is performed with a 2-tap PFB/FFT and 64 bit accumulated spectral values are broken up along byte boundaries to allow fast dumping of 8-bit resolution spectra. Maximum readout is about 1600 Hz using 100 Mbit ethernet.
  
  Dependencies: This design uses legacy (pink) blocks.
  
  

Correlators

• Design Name: Pocket Correlator w/ LWIP -- Model File - Software - Wiki
  
  Design Author(s): Aaron Parsons, Andrew Siemion
  
  Application: This pocket correlator design was built primarily for the University of North Carolina's PARI Observatory, where it is being deployed on a pair of 26 meter dishes.
  
  Description: This 1024 channel IBOB-based pocket correlator design is a modified version of the original PoCo/F-Engine design in which F-Engine logic has been stripped out to allow the addition of LWIP functionality for fast-readout and programmable delay lines (on one input). Compiled for a sampling rate of 800 Msamp/sec, this design utilizes two ADCs to act as either a 2 antenna full Stokes correlator or 4 antenna single polarization correlator. When clocked at 800 MHz, a digital down converter selects a 200 MHz band between 100 and 300 MHz for processing. A programmable sync generator can specify accumulation times as short as about 100 msec.
  
  Dependencies: This design uses legacy (pink) blocks.
  
  



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• Design Name: SatCorr -- Model File - Software(SVN) - Wiki
  
  Design Author(s): Aaron Parsons, Andrew Siemion, Griffin Foster
  
  Application: This pocket correlator design was built to have a high frequency channel resolution in a small band to resolve the signal of OrbCom Satellites to calibrate the antenna gains of the PAPER array.
  
  Description: This 1024 channel IBOB-based pocket correlator design is optimized to get high frequency resolution by decreasing the bandwidth. Compiled for a sampling rate of 108 Msamp/sec, this design utilizes two ADCs to act as either a 2 antenna full Stokes correlator or 4 antenna single polarization correlator. When clocked at 108 MHz, a digital down converter selects a 13,5 MHz band and using aliasing we center around 137.5 MHz for processing. A programmable sync generator can specify accumulation times as short as about 100 msec. Using the python correlator receive/transmit code the PoCo writes out MIRIAD files.
  
  Dependencies: This design uses legacy (pink) blocks.