scholarly journals MIDAS-W: a workstation-based incoherent scatter radar data acquisition system

2000 ◽  
Vol 18 (9) ◽  
pp. 1231-1241 ◽  
Author(s):  
J. M. Holt ◽  
P. J. Erickson ◽  
A. M. Gorczyca ◽  
T. Grydeland

Abstract. The Millstone Hill Incoherent Scatter Data Acquisition System (MIDAS) is based on an abstract model of an incoherent scatter radar. This model is implemented in a hierarchical software system, which serves to isolate hardware and low-level software implementation details from higher levels of the system. Inherent in this is the idea that implementation details can easily be changed in response to technological advances. MIDAS is an evolutionary system, and the MIDAS hardware has, in fact, evolved while the basic software model has remained unchanged. From the earliest days of MIDAS, it was realized that some functions implemented in specialized hardware might eventually be implemented by software in a general-purpose computer. MIDAS-W is the realization of this concept. The core component of MIDAS-W is a Sun Microsystems UltraSparc 10 workstation equipped with an Ultrarad 1280 PCI bus analog to digital (A/D) converter board. In the current implementation, a 2.25 MHz intermediate frequency (IF) is bandpass sampled at 1 µs intervals and these samples are multicast over a high-speed Ethernet which serves as a raw data bus. A second workstation receives the samples, converts them to filtered, decimated, complex baseband samples and computes the lag-profile matrix of the decimated samples. Overall performance is approximately ten times better than the previous MIDAS system, which utilizes a custom digital filtering module and array processor based correlator. A major advantage of MIDAS-W is its flexibility. A portable, single-workstation data acquisition system can be implemented by moving the software receiver and correlator programs to the workstation with the A/D converter. When the data samples are multicast, additional data processing systems, for example for raw data recording, can be implemented simply by adding another workstation with suitable software to the high-speed network. Testing of new data processing software is also greatly simplified, because a workstation with the new software can be added to the network without impacting the production system. MIDAS-W has been operated in parallel with the existing MIDAS-1 system to verify that incoherent scatter measurements by the two systems agree. MIDAS-W has also been used in a high-bandwidth mode to collect data on the November, 1999, Leonid meteor shower.Key words: Electromagnetics (instruments and techniques; signal processing and adaptive antennas) – Ionosphere (instruments and techniques)

2011 ◽  
Vol 403-408 ◽  
pp. 1592-1595
Author(s):  
Guo Sheng Xu

A new kind of data acquisition system is introduced in this paper, in which the multi-channel synchronized real-time data acquisition under the coordinate control of field-programmable gate array(FPGA) is realized. The design uses field programmable gate arrays(FPGA) for the data processing and logic control. For high speed CCD image data processing, the paper adopts regional parallel processing based on FPGA. The FPGA inner block RAM is used to build high speed image data buffer is put into operation to achieve high speed image data integration and real-time processing. The proposed data acquisition system has characteristics of stable performance, flexible expansion, high real-timeness and integration


IERI Procedia ◽  
2012 ◽  
Vol 2 ◽  
pp. 444-449 ◽  
Author(s):  
Zhong Luan ◽  
Weigong Zhang ◽  
Yongxiang Zhang ◽  
Yan Lu

2012 ◽  
Vol 546-547 ◽  
pp. 1393-1397
Author(s):  
Zhi Wen Xiong ◽  
Chen Guang Xu ◽  
Hong Zeng

Data acquisition begins with the physical phenomenon or physical property to be measured. Examples of this include temperature, gas pressure, and light intensity, and force, fluid flow, regardless of the type of physical property to be measured. Physical property converted into digital, and then by the computer for storage, processing, display or printing process, the corresponding system is called data acquisition system. With the rapid development of computer technology, data acquisition systems quickly gained popularity. A variety of products based on digital technology have been created. Digital System spread quickly; it’s mainly the following two advantages: the first is the digital processing flexible and convenient; the second is a digital system is very reliable. The main idea of Reconfigurable computing technology [1] is using the FPGA [2][3] allows the system has a dynamically configurable capacity, suitable for harsh environment applications, improve the speed of data processing. By the use of dynamic reconfigurable FPGA devices can be realized on the hardware logic function modification, application of reconfigurable computing technology can improve the speed of data processing. Data acquisition system is widely applied in many fields, and often used the abominable working environment place. The reconfigurable computing technology, can greatly improve the data acquisition system reliability and safety. The paper introduces a kind of multi-channel data acquisition system based on USB bus and FPGA, the factors affecting the performance of system are discussed, and describes how to use reconfigurable computing technology to improve the efficiency of data acquisition system while reduce energy consumption. The system in this paper uses AD's AD9220, ALTERA's EP1C6-8 and IDT's IDT70V24, Cypress’s CY7C68013.


2021 ◽  
Vol 21 (10) ◽  
pp. 248
Author(s):  
Xin Pei ◽  
Jian Li ◽  
Na Wang ◽  
Toktonur Ergesh ◽  
Xue-Feng Duan ◽  
...  

Abstract A multi-function digital baseband data acquisition system is designed for the sampling, distribution and recording of wide-band multi-channel astronomical signals. The system hires a SNAP2 board as a digital baseband converter to digitize, channelize and packetize the received signal. It can be configured dynamically from a single channel to eight channels with a maximum bandwidth of 4096 MHz. Eight parallel HASHPIPE instances run on four servers, each carrying two NVMe SSD cards, achieving a total continuous write rate of 8 GB s−1. Data are recorded in the standard VDIF file format. The system is deployed on a 25-meter radio telescope to verify its functionality based on pulsar observations. Our results indicate that during the 30-minute observation period, the system achieved zero data loss at a data recording rate of 1 GB s−1 on a single server. The system will serve as a verification platform for testing the functions of the QTT (QiTai radio Telescope) digital backend system. In addition, it can be used as a baseband/VLBI (Very Long Baseline Interferometry) recorder or D-F-engine of correlator/beamformer as well.


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