阅读说明：本技术 一种能记录时间标识和星象扫描的科学级ccd/cmos相机 (Scientific grade CCD/CMOS camera capable of recording time mark and star image scanning ) 是由 张晓祥 门金瑞 温昌礼 徐蓉 曹景太 于 2021-06-23 设计创作，主要内容包括：本发明公开了一种能记录时间标识和星象扫描的科学级CCD/CMOS相机,其特征在于：包括图像采集分系统以及分别与其连接的计时分系统、星象扫描分系统、数据传输分系统。本发明CCD/CMOS相机可在内部实现采集图像曝光中心时刻和采集图像的一一对应,从而避免不同操作系统因图像采集问题造成的采集图像和时间标识不对应的问题,尤其是避免了帧转移读出CCD无法实现帧转移造成曝光模式下记录的时间标识和图像不对应的问题；通过对图像上所有星象的扫描处理,将需要传输的数据量降低为图像原始数据的百分之一以下,在较低读出速度的情况下,可有效的降低数据传输时间,适合在空间碎片监测的技术领域中推广使用。(The invention discloses a scientific grade CCD/CMOS camera capable of recording time identification and astrology scanning, which is characterized in that: comprises an image acquisition subsystem, and a timing subsystem, a star image scanning subsystem and a data transmission subsystem which are respectively connected with the image acquisition subsystem. The CCD/CMOS camera can realize one-to-one correspondence between the acquired image exposure center time and the acquired image in the camera, thereby avoiding the problem that the acquired image and the time identification are not corresponding due to the image acquisition problem of different operating systems, and particularly avoiding the problem that the time identification and the image which are recorded in an exposure mode are not corresponding due to the fact that the frame transfer reading CCD cannot realize the frame transfer; through the scanning processing of all the stars on the image, the data volume required to be transmitted is reduced to be less than one percent of the original data of the image, and under the condition of low reading speed, the data transmission time can be effectively reduced, so that the method is suitable for being popularized and used in the technical field of space debris monitoring.)

1. A scientific grade CCD/CMOS camera capable of recording time stamps and star scans characterized by: including image acquisition subsystem and respectively rather than the timing subsystem, astrology scanning subsystem, data transmission subsystem of being connected, wherein:

1) timing subsystem

The timing subsystem is provided with a GPS/BD antenna interface, a GPS/BD receiving chip and a first FPGA controller, the GPS/BD antenna interface is used for being connected with a GPS/BD satellite receiving antenna, the signal output end of the GPS/BD receiving chip is connected with the signal input end of the GPS/BD receiving chip, the timing subsystem receives a GPS/BD signal through the GPS/BD satellite receiving antenna, the GPS/BD receiving chip generates a second pulse signal and a second packet, the signal output end of the GPS/BD receiving chip is connected with a TTL differential device, and the second pulse signal is converted into a differential second signal which is output to the first FPGA controller;

the first FPGA controller is configured to:

receiving the differential second signal and the second packet, and generating and synchronizing a real-time synchronous timekeeping system according to UTC time provided by the second packet data and the synchronous property of the rising edge of the differential second signal and the whole second;

recording the initial time and the ending time of each frame of image exposure according to an image exposure pulse signal provided by the image acquisition subsystem, calculating the whole exposure duration and the central time of the exposure, and feeding back the central time as the time identification data of each frame of image to the image acquisition subsystem;

2) an image acquisition subsystem;

the image acquisition subsystem is provided with a CMOS or CCD detector chip, a detector chip driving and reading driving circuit, an image data cache device and a second FPGA controller;

the image data cache device is used for storing image data acquired by the second FPGA controller;

the second FPGA controller is configured to:

setting working parameters according to an acquisition mode instruction sent by an upper computer, outputting corresponding control signals to a driving and reading driving circuit of a detector chip, and driving the detector chip to work and read data through the driving and reading driving circuit of the detector chip;

acquiring single-frame or continuous-frame images according to the working parameters, sending the acquired single-frame or continuous-frame images to the star image scanning subsystem, and sending an acquisition ending mark to the star image scanning subsystem when the acquisition of each frame of image is ended;

in the acquisition process, outputting an image exposure pulse signal to a timing subsystem in real time, aligning the rising edge of the image exposure pulse signal with the exposure starting time of each time, and aligning the falling edge with the exposure finishing time of the time;

enabling the star image data fed back by the star image scanning subsystem to correspond to the time identification data fed back by the timing subsystem one by one, and packaging and sending the star image data to an upper computer;

3) astrology scanning subsystem

The star image scanning subsystem is provided with a third FPGA processor or a DSP processor;

the third FPGA processor or DSP processor is used for:

detecting an acquisition end mark, scanning the received image frames according to a preset image processing algorithm to obtain star image data of each frame of image, and feeding back the star image data to the image acquisition subsystem in sequence; the star image data comprises the position, the gray sum, the pixel number, the signal-to-noise ratio and the mean value and the variance of the background near the star image of the star image;

4) data transmission subsystem

The data transmission subsystem is provided with a communication interface and is used for establishing communication connection between the image acquisition subsystem and an upper computer so as to transmit the star data and the time identification data to the upper computer.

2. A scientific grade CCD/CMOS camera capable of recording time stamps and star scans according to claim 1, characterized by:

the first FPGA controller is provided with a constant-temperature crystal oscillator, a rubidium clock or a cesium clock, and when a pulse per second signal and package data are lost, the first FPGA controller accurately keeps time of signals for system time by utilizing the constant-temperature crystal oscillator, the rubidium clock or the cesium clock.

3. A scientific grade CCD/CMOS camera capable of recording time stamps and star scans according to claim 1, characterized by:

the image data cache device adopts DDR.

4. A scientific grade CCD/CMOS camera capable of recording time stamps and star scans according to claim 1, characterized by:

the communication interface of the data transmission subsystem is any one of a USB3.0 or a gigabit Ethernet interface.

Technical Field

The invention belongs to the technical field of astronomy, and particularly relates to a scientific grade CCD/CMOS camera capable of recording time marks and star image scanning.

Background

In many fields such as scientific research, military affairs and the like, the space debris needs to be monitored, angle measurement data of each observation moment of the space debris is given, and therefore the operation orbit of the space debris is determined, accurate information of the space debris is obtained, and the most original support data is provided for the safety of the in-orbit spacecraft.

The invention of CCD in the 70 th century replaces the traditional observation of the celestial body with photography, and becomes an effective means for artificial satellite monitoring. With the frequent activity of space launching, the number of the space launching is increased to more than 100 times from several times, dozens of times per year. The space debris in the space is more and more, the space debris larger than 1 cm reaches tens of thousands, even hundreds of thousands, and the safety of the on-orbit working spacecraft is threatened. To obtain information about these space fragments, they must be observed in large numbers. Therefore, the aperture of the optical telescope is also larger and larger, and the target surface of the scientific grade CCD camera is also larger and larger. Due to the problem of the CCD reading mode, on one hand, the large-target-surface scientific CCD camera adopts a full-frame reading mode and needs a mechanical shutter to be in a dark state in the image reading process, and on the other hand, the large-target-surface scientific CCD camera needs to meet the requirement of lower reading noise at a lower reading speed, so that the reading time is too long, and the traditional large-target-surface scientific CCD camera cannot meet the requirement of space debris observation. Therefore, a scientific grade CMOS camera with a large target surface appears, the target surface can be more than 60mm x 60mm, and the frame frequency can be 5 Hz.

Common scientific grade CCD and CMOS cameras have several features:

1) the image can be acquired in a single frame or continuously according to the given exposure time;

2) images can be continuously acquired according to an externally input TTL level signal with fixed frequency;

3) exposure square wave TTL level signals can be output, but a frame transfer read CCD is read in the exposure process, and the exposure square wave TTL level signals are not normally available;

however, as space debris in space increases, conventional scientific grade CCD and CMOS cameras are becoming less and less suitable for space debris inventory development requirements.

Disclosure of Invention

Based on the problems described in the background art, the invention provides a scientific grade CCD/CMOS camera capable of recording time identification and astrology scanning, which can realize integration of image time identification recording and image acquisition and processing and avoid the problem that time identification and images do not correspond.

The technical scheme provided by the invention is as follows:

a scientific grade CCD/CMOS camera capable of recording time stamps and star scans characterized by: including image acquisition subsystem and respectively rather than the timing subsystem, astrology scanning subsystem, data transmission subsystem of being connected, wherein:

1) timing subsystem

The timing subsystem is provided with a GPS/BD antenna interface, a GPS/BD receiving chip and a first FPGA controller, the GPS/BD antenna interface is used for being connected with a GPS/BD satellite receiving antenna, the signal output end of the GPS/BD receiving chip is connected with the signal input end of the GPS/BD receiving chip, the timing subsystem receives a GPS/BD signal through the GPS/BD satellite receiving antenna, the GPS/BD receiving chip generates a second pulse signal and a second packet, the signal output end of the GPS/BD receiving chip is connected with a TTL differential device, and the second pulse signal is converted into a differential second signal which is output to the first FPGA controller;

the first FPGA controller is configured to:

receiving the differential second signal and the second packet, and generating and synchronizing a real-time synchronous timekeeping system according to UTC time provided by the second packet data and the synchronous property of the rising edge of the differential second signal and the whole second;

recording the initial time and the ending time of each frame of image exposure according to an image exposure pulse signal provided by the image acquisition subsystem, calculating the whole exposure duration and the central time of the exposure, and feeding back the central time as the time identification data of each frame of image to the image acquisition subsystem;

2) an image acquisition subsystem;

the image acquisition subsystem is provided with a CMOS or CCD detector chip, a detector chip driving and reading driving circuit, an image data cache device and a second FPGA controller;

the image data cache device is used for storing image data acquired by the second FPGA controller;

the second FPGA controller is configured to:

setting working parameters according to an acquisition mode instruction sent by an upper computer, outputting corresponding control signals to a driving and reading driving circuit of a detector chip, and driving the detector chip to work and read data through the driving and reading driving circuit of the detector chip;

acquiring single-frame or continuous-frame images according to the working parameters, sending the acquired single-frame or continuous-frame images to the star image scanning subsystem, and sending an acquisition ending mark to the star image scanning subsystem when the acquisition of each frame of image is ended;

in the acquisition process, outputting an image exposure pulse signal to a timing subsystem in real time, aligning the rising edge of the image exposure pulse signal with the exposure starting time of each time, and aligning the falling edge with the exposure finishing time of the time;

enabling the star image data fed back by the star image scanning subsystem to correspond to the time identification data fed back by the timing subsystem one by one, and packaging and sending the star image data to an upper computer;

3) astrology scanning subsystem

The star image scanning subsystem is provided with a third FPGA processor or a DSP processor;

the third FPGA processor or DSP processor is used for:

detecting an acquisition end mark, scanning the received image frames according to a preset image processing algorithm to obtain star image data of each frame of image, and feeding back the star image data to the image acquisition subsystem in sequence; the star image data comprises the position, the gray sum, the pixel number, the signal-to-noise ratio and the mean value and the variance of the background near the star image of the star image;

4) data transmission subsystem

The data transmission subsystem is provided with a communication interface and is used for establishing communication connection between the image acquisition subsystem and an upper computer so as to transmit the star data and the time identification data to the upper computer.

On the basis of the above scheme, a further improved or preferred scheme further comprises:

further, the first FPGA controller is provided with a constant-temperature crystal oscillator, a rubidium clock or a cesium clock, and when a pulse per second time signal and packet per second data are lost, the first FPGA controller accurately keeps time of the signal of the system time by using the constant-temperature crystal oscillator, the rubidium clock or the cesium clock.

Preferably, the image data cache device employs DDR.

Further, the communication interface of the data transmission subsystem is any one of a USB3.0 interface or a gigabit ethernet interface.

Has the advantages that:

the CCD/CMOS camera can realize one-to-one correspondence between the acquired image exposure center time and the acquired image in the camera, thereby avoiding the problem that the acquired image and the time identification are not corresponding due to the image acquisition problem of different operating systems, and particularly avoiding the problem that the time identification and the image which are recorded in an exposure mode are not corresponding due to the fact that the frame transfer reading CCD cannot realize the frame transfer; through the scanning processing of all the stars on the image, the data volume needing to be transmitted is reduced to be less than one percent of the original data of the image, and the data transmission time can be effectively reduced under the condition of low reading speed.

Drawings

FIG. 1 is a system architecture diagram of a camera of the present invention;

FIG. 2 is a flow chart of the operation of the camera in the single frame acquisition mode of the present invention:

fig. 3 is a flowchart of the operation of the camera in the multi-frame acquisition mode.

Detailed Description

To clarify the explanation of the technical solution and principle of the present invention, the following detailed description of the invention is made with reference to the accompanying drawings and specific examples.

The scientific grade CCD/CMOS camera for recording time marks and astrology scanning as shown in figure 1 comprises an image acquisition subsystem, and a timing subsystem, an astrology scanning subsystem and a data transmission subsystem which are respectively connected with the image acquisition subsystem.

1) Timing subsystem

The timing subsystem is provided with a GPS/BD antenna interface, a GPS/BD receiving chip and a first FPGA controller. The GPS/BD antenna interface is used for connecting a GPS/BD satellite receiving antenna, and the signal output end of the GPS/BD antenna interface is connected with the signal input end of a GPS/BD receiving chip. The timing subsystem receives GPS/BD signals through a GPS/BD satellite receiving antenna, and enables a GPS/BD receiving chip to generate a Pulse Per Second (PPS) and a second packet (a serial data packet which is sent out at the rising edge of the PPS and contains information such as the position, the time, the satellite number and the like of the whole second). And the signal output end of the GPS/BD receiving chip is connected with the TTL differential conversion device, and the second pulse signal (PPS) is converted into a differential second signal and output to the first FPGA controller.

The first FPGA controller is configured to:

A. receiving the differential second signal and the second packet, and generating and synchronizing a real-time synchronous timekeeping system according to UTC time provided by the second packet data and the synchronous property of the rising edge of the differential second signal and the whole second; when the pulse per second time signal and the packet per second data are lost, the first FPGA controller can accurately keep time of the signal of the system time by utilizing a self high-precision constant-temperature crystal oscillator, a rubidium clock or a cesium clock;

B. recording the initial time and the ending time of each frame of image exposure according to an image exposure pulse signal provided by the image acquisition subsystem, calculating the whole exposure duration and the central time of exposure, and feeding back the central time as the time identification data of each frame of image to the image acquisition subsystem.

2) Image acquisition subsystem

The image acquisition subsystem is provided with a CMOS or CCD detector chip, a detector chip driving and reading driving circuit, an image data cache device DDR and a second FPGA controller.

And the image data cache device DDR is used for storing the image data acquired by the second FPGA controller.

The second FPGA controller is mainly used for controlling image acquisition and generation of drive signal logic, and specifically comprises:

A. setting working parameters (including exposure parameters, acquisition frequency and the like) according to an acquisition mode instruction sent by a PC upper computer, outputting corresponding control signals to a driving and reading driving circuit of a detector chip, and driving the detector chip to work and read data through the driving and reading driving circuit of the detector chip;

B. acquiring a single-frame image according to the set exposure time, and sending the image and an image acquisition end mark to a star image scanning system; or, collecting multiple frames of images according to the set exposure time and the set collection frequency, and continuously sending the images and the collection end marks of the images of the multiple frames to the star image scanning system;

C. in the acquisition process, outputting an image exposure pulse signal to a timing subsystem in real time, aligning the rising edge of the image exposure pulse signal with the exposure starting time of each time, and aligning the falling edge with the exposure finishing time of the time;

D. the star image data fed back by the star image scanning subsystem and the time identification data (the central time of exposure) fed back by the timing subsystem are in one-to-one correspondence, packaged and sent to the upper computer.

3) Astrology scanning subsystem

The star image scanning subsystem is provided with a third FPGA processor or a DSP processor and is used for processing image data, and the method specifically comprises the following steps:

and detecting the acquisition ending mark, scanning the received image frames according to a preset image processing algorithm to obtain the star image data of each frame of image, and feeding back the star image data to the image acquisition subsystem in sequence. The star image data comprises information such as the position, the gray sum, the pixel number, the signal-to-noise ratio, the mean value and the variance of the background near the star image and the like of the star image.

4) Data transmission subsystem

The data transmission subsystem is provided with a communication interface and is used for connecting the image acquisition subsystem and the upper computer to establish communication between the image acquisition subsystem and the upper computer so as to transmit the star image data and the time identification data to the PC upper computer.

The communication interface of the data transmission subsystem can adopt any one of a USB3.0 or gigabit/gigabit Ethernet interface.

The scientific grade CCD/CMOS camera of the invention mainly works in two modes, namely a single-frame acquisition mode and a continuous acquisition mode with fixed frequency.

As shown in fig. 2, in the single frame acquisition mode:

the method comprises the steps that after a camera receives an acquisition mode instruction sent by an upper computer, exposure time is set, then a detector is triggered to carry out exposure integration, meanwhile, a timing subsystem records the initial time and the exposure duration of exposure, after the exposure is finished, an image is sent to a star image scanning subsystem to carry out image processing, star image data in the image are obtained and comprise information such as coordinates, signal-to-noise ratios, gray values and occupied pixel numbers of stars and target points, and finally the star image scanning data and identification time information fed back by the timing subsystem are packaged and sent to the upper computer.

As shown in fig. 3, in the multi-frame acquisition mode:

and after receiving an acquisition mode instruction sent by the upper computer, the camera circularly executes a single-frame acquisition mode according to a fixed frequency and sends the star image scanning data and time information to the upper computer.

For the frame transfer detector, because image reading and exposure can be carried out simultaneously, namely two frames of images exist simultaneously in a continuous mode, the first frame is read in a pixel storage area, the second frame is exposed, the corresponding relation between the two frames of images and two time information packets needs to be processed, the dislocation phenomenon can occur in a common frame transfer camera because image acquisition and time acquisition are independent, and the condition that time and images do not correspond can be well avoided because a fixed time sequence logic is designed in the camera, so that the camera is suitable for being applied to monitoring of space debris.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to explain the principles of the invention, and that various changes and modifications may be made therein without departing from the spirit and scope of the invention. The scope of the invention is defined by the appended claims, the description and their equivalents.