Signal acquisition and processing system and method

Abstract

The invention provides a signal acquisition and processing system. The system is used for collecting and processing multiple paths of array element signals received by a phased array feed source. Thesystem comprises: a signal acquisition and preprocessing unit comprising a first preset number of nodes, each node acquiring a preset number of array element signals, preprocessing the array element signals, dividing the preprocessed array element signals into a second preset number of narrowband signals of different frequency bands, and outputting the second preset number of narrowband signals; acorrelation and beam forming unit which comprises a third preset number of nodes, wherein each node synthesizes the narrowband signals of the fixed frequency band in the first preset number of nodesinto a fourth preset number of beams; and a multi-beam astronomical processing unit which is used for analyzing and storing the beams.

Description

technical field [0001] The invention relates to the technical field of radio telescopes, in particular to a signal acquisition and processing system and method. Background technique [0002] The field of view (Field of View, FOV) of a radio telescope is an important index that reflects the telescope's ability to survey the sky, and it characterizes the scope of the observable sky area at any given moment. For a single-aperture radio telescope, the field of view and resolution can be expressed by half-power beam width (Half-power Beam Width, HPBW): HPBW=1.02λ / D, where λ is the observation wavelength, and D is the telescope’s diameter. Large-aperture radio telescopes obtain higher resolution and sensitivity by increasing the diameter D, but at the same time, the field of view of the telescope decreases with the increase of the aperture, resulting in a decrease in the area of ​​the observed sky area per unit time. For observations such as pulsar or transient source search, mo...

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Problems solved by technology

[0003] However, large-scale PAF feeds are densely arranged and numerous in number. If the traditional superheterodyne receiver design is adopted, each feed needs to be equipped with analog mixing, filtering, and amplification devices. The scale of analog devices will be very large. On the one hand, the complexity of the system increases, and the analog link will occupy a large space, which increases the difficulty of designing a compact PAF. At the same time, too many analog devices will increase the size and weight of the receiver, causing the format position of the telescope to change with the pitch , thus affecting the pointing and efficiency of the telescope; on the other hand, due to differences in the consistency of analog devices, this will lead to different signal responses of different channels, which will cause signal gain and phase fluctuations when the ambient temperature changes, affecting PAF beamforming signal quality

Large-scale PAF has a high signal rate, many channels, and a huge amount of data after sampling. In addition, the data processing algorithm is complex and requires high real-time performance. It is impossible to transmit all Zhenyuan signals to a single computing node for processing. Generally, a distributed computing architecture is used. Computing nodes process a narrowband signal

At this time, the data stream of a single array element will be transmitted to multiple computing nodes for use, and a single computing node will receive the data streams of multiple array elements. The integrity of the data and the real-time nature of data processing pose a great challenge

In addition, digital devices are close to the receiver, which will cause strong electromagnetic interference for large-aperture telescopes with high sensitivity. How to reduce the electromagnetic radiation of digital devices is a major difficulty in design

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