Using the ID-1 Digital Tape Recorder to Collect Radio Telescope Data

Transcription

1 Using the ID-1 Digital Tape Recorder to Collect Radio Telescope Data DATATAPE Incorporated October 17-18, 1995 Presented by Manny Soria Prepared by Manny Soria and Dr. Tom Prince of Caltech 95/11/25 Page 1

2 Project Overview Agenda What is a Pulsar? What can we learn from studying pulsars? How pulsar data is collected using the DATATAPE LP 400 ID-1 recorder How pulsar data is analyzed using the Intel Paragon supercomputer and the ID-1 recorder 95/11/25 Page 2

3 Project Overview Funding from National Science Foundation s Grand Challenge Applications Program Caltech, Intel, DATATAPE Incorporated Multi-year project to collect and analyze pulsar data Principles Dr. Tom Prince Caltech Dr. Steve Unwin Caltech Rick Jenet Caltech Radio telescopes at Owens Valley Radio Observatory in California and Parkes Observatory in Australia 95/11/25 Page 3

4 What is a Pulsar? Pulsars are highly magnetic neutron stars that represent the remains of a star after it dies Spin at up to 1000 revolutions/sec Very accurate clocks Neutron stars start out approx 1.5 times the mass of the sun and compact to about the size of Pasadena Calif. Emit regular bursts of radio waves Millisecond pulsars found in globular clusters Some of the oldest constituents of our galaxy Questions: How do they form? Why do pulsars seem to evolve by spinning down and then spinning up again? 95/11/25 Page 4

5 What Can We Learn from Studying Pulsars? Achieve a better understanding of the behavior of nuclear matter in very dense situations Pulsars surfaces spin at close to the speed of light An understanding of how fast they can spin will clarify how dense nuclei can become Verify portions of Einstein's theory of relativity Fundamental test of physics Understand gravitational waves by two objects in orbit Pulsars are the most accurate clocks known Why are they so accurate and predictable? 95/11/25 Page 5

6 How Pulsar Data is Collected Using the ID 1 Recorder Collection of pulsar data requires sensitive radio telescopes that capture radio signals Continuous data is received by the radio telescope Bandwidths range from MHz The data is bandpass filtered and amplified The data is converted from RF to digital The digital data is recorded on the ID-1 recorder at 50 and 25 MBytes/sec 95/11/25 Page 6

7 Pulsar Data Collection Block Diagram (Record) Radio Telescope RF 600 MHz Bandpass Filter and Amplifier MHz A:D Converter 2 bits 4 channels RS-232 To Tape Recorder 8 bits parallel 1 bit parity CMDS and Time Code LP MBytes/s 50, 25 or 12.5 MHz Write Clock RS-232 Time Code RS-232 Command Interface Microprocessor Controller 95/11/25 Page 7

8 How Pulsar Data is Analyzed Using the Intel Paragon Supercomputer and the ID-1 Recorder The study of pulsars is a signal processing application Dispersion must be corrected by complex computational algorithms Requires high performance computing similar to medical diagnostic imaging, seismic data processing, or environmental impact studies Intel Paragon filters and analyzes the data checks data integrity, data reduction, and signal dedispersion Data is analyzed to determine if pulsar activity is detected Over 10 Terabytes of data was collected over 2 weeks in July of 1995 (analysis ongoing) 95/11/25 Page 8

9 Pulsar Data Analysis Block Diagram (Playback) LP MBytes/s Variable Rate Buffer HIPPI VRB Adapter HIPPI Switch Intel Paragon 96 GBytes/Tape 50, 25 and 12.5 MBytes/s Playback Analysis Work Station 95/11/25 Page 9

10 Summary Supercomputing application using COTS equipment and standard interfaces ID-1 digital tape recorder HIPPI connected Intel Paragon High transfer rates (up to 50 Mbyte/s) Large tape capacity (up to 98 Gbytes/cassette) Same technology can be used for instrumentation, data analysis, data warehousing, SAR imagery, and image rendering applications 95/11/25 Page 10