OTF (optical transfer function) observation scanning method

Abstract

The invention relates to an OTF observation scanning method. The method comprises the steps as follows: one scanning area is divided into a plurality of rows; a plurality of interlaced rows are scanned each time; interlaced scanning is performed for a plurality of times; and the whole scanning area is scanned. One-time scanning can cover the whole area rapidly with the interlaced scanning method under the condition that parameters of the antenna scanning speeds, sampling intervals and time intervals of observation reference points are the same, so that influences of factors such as telescope system performance, weather changes and the like on the distribution of the whole area are reduced; and when a interlaced scanning result is subjected to remeshing processing, reference points of data of adjacent rows in one meshed area are observed at different time, different reference points are independent, and the sum of integration of reference points of different rows is effective integral time of the reference points, so that the integral time of the reference points can be determined according to 1/k during line by line scan, wherein the k is the scanning time of one scanning area.

Description

[0001] technical field [0002] The invention relates to the field of radio astronomical telescopes, in particular to an OTF observation and scanning method. Background technique [0003] OTF (On The Fly) is an observation method for radio telescopes. The antenna scans the specified area at a constant rate without tracking a single grid point. Multiple source points can share reference points and blackbody calibration, saving time; Since the entire area is quickly scanned, changes in system performance and weather over time will have less impact on observations. [0004] In order to avoid the loss of information due to insufficient sampling, there are some restrictions on OTF scanning parameters, such as the distance between two adjacent scanning lines cannot be greater than the "Nyquist interval"; the sampling interval, that is, the single integration time, should be greater than the receiver backend The minimum time required to obtain a set of valid data; the distance sca...

AI Technical Summary

Problems solved by technology

[0006]The traditional scanning method is to divide a scanning area into several lines, and start scanning line by line from one direction (such as Figure 1), for a relatively large scanning area, if you want to scan it quickly, you need to speed up the scan Speed, speeding up the scanning speed means shortening the integration time of each point; shortening the integration time of each point means that the integration time of each grid point is short after the data regrid of a single scan, and the noise is large, requiring multiple scans; shortening each Long scanning time means that the antenna turns around frequently, which is not conducive to improving observation efficiency; if the scanning speed is slow, it will take a long time to complete a scan, which is not conducive to reducing the impact of telescope

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