阅读说明：本技术 基于ccsds架构的飞行图像解码方法和系统 (Flight image decoding method and system based on CCSDS framework ) 是由 潘晓明 庄玮 刘伟 吴睫 赵阳 蔡珂 于 2020-06-19 设计创作，主要内容包括：本发明提供了一种基于CCSDS架构的飞行图像解码方法和系统,该方法包括：通过遥测地面站将飞行器在飞行过程中的图像压缩码流转发给图像处理器；其中,飞行器侧生成的所述图像压缩码流按照CCSDS标准信道码传输给所述遥测地面站；图像处理器对所述图像压缩码流进行解码处理,得到解码后的图像数据。从而可以有效地提升飞行器飞行图像解码的可靠性和时效性,提升解码图像的质量。(The invention provides a flight image decoding method and a system based on a CCSDS framework, wherein the method comprises the following steps: forwarding the image compression code stream of the aircraft in the flight process to an image processor through a telemetering ground station; the image compressed code stream generated by the aircraft side is transmitted to the telemetering ground station according to a CCSDS standard channel code; and the image processor decodes the image compressed code stream to obtain decoded image data. Therefore, the reliability and timeliness of decoding the flight images of the aircraft can be effectively improved, and the quality of the decoded images is improved.)

1. A flight image decoding method based on a CCSDS (consultative committee for space data system) architecture is characterized by comprising the following steps:

step 1: forwarding the image compression code stream of the aircraft in the flight process to an image processor through a telemetering ground station; the image compressed code stream generated by the aircraft side is transmitted to the telemetering ground station according to a CCSDS standard channel code;

step 2: and the image processor decodes the image compressed code stream to obtain decoded image data.

2. The CCSDS based flight image decoding method according to claim 1, wherein the step 1 comprises:

the remote measuring ground station sends the image compression code stream to the image processor through a UDP multicast protocol; the image compression code stream comprises: channel identification, a pilot header and a data field; wherein the content of the first and second substances,

the channel identification is used for calling the control logic of the corresponding state according to the state parameter;

the master header is used to provide a frame: any one or more of a version number, a spacecraft identifier, a virtual channel frame counter;

the data field is used for recording an engineering telemetry source packet, a data transmission data frame and an idle data frame;

the data transmission frame includes: surveillance camera image data, GNSSB raw measurement data, and backup data.

3. The CCSDS-based flying image decoding method according to claim 2, wherein the step 2 comprises:

sequentially extracting data transmission frames in a data domain according to a virtual channel identifier in a main header provided by a CCSDS (consultative committee for space data system) architecture, and storing the data transmission frames as data streams;

and decoding the image data frames with different lengths in the data stream according to the value of the virtual channel counter provided by the CCSDS framework to obtain decoded image data.

4. The CCSDS based flight image decoding method according to any one of claims 1 to 3, further comprising:

and step 3: and playing the decoded image data.

5. The CCSDS based flight image decoding method according to claim 4, wherein the step 3 comprises:

displaying the decoded image data on one or more displays;

and adjusting the size and/or the display time length of a display frame on any display.

6. A flight image decoding system based on a CCSDS (consultative Committee space System) architecture, which is characterized by comprising: a telemetric ground station and an image processor communicatively coupled; wherein:

the telemetering ground station is used for forwarding the image compression code stream of the aircraft in the flight process to the image processor;

and the image processor is used for decoding the image compression code stream to obtain decoded image data.

7. The CCSDS architecture based flight image decoding system of claim 6, wherein the telemetry ground station is specifically configured to:

sending the image compressed code stream to the image processor through a UDP multicast protocol; the image compression code stream comprises: channel identification, a pilot header and a data field; wherein the content of the first and second substances,

the channel identification is used for calling the control logic of the corresponding state according to the state parameter;

the master header is used to provide a frame: any one or more of a version number, a spacecraft identifier, a virtual channel frame counter;

the data field is used for recording an engineering telemetry source packet, a data transmission data frame and an idle data frame; the data transmission frame includes: surveillance camera image data, GNSSB raw measurement data, and backup data.

8. The CCSDS based flight image decoding system of claim 7, wherein the image processor is specifically configured to:

sequentially extracting data transmission frames in a data domain according to a virtual channel identifier in a main header provided by a CCSDS (consultative committee for space data system) architecture, and storing the data transmission frames as data streams;

and decoding the image data frames with different lengths in the data stream according to the value of the virtual channel counter provided by the CCSDS framework to obtain decoded image data.

9. The CCSDS architecture based flight image decoding system of any of claims 6 to 8, further comprising:

and the display is used for receiving and playing the decoded image data.

10. The CCSDS architecture based flight image decoding system of claim 9, wherein the display is further configured to: and adjusting the size of the display picture and/or the display time length.

Technical Field

The invention relates to the technical field of image processing, in particular to a flight image decoding method and system based on a Consultative Committee (CCSDS) architecture of an international spatial Data system.

Background

In the field of deep space flight communication, due to huge signal energy attenuation, input signals of a receiving end are very small, and therefore huge challenges are brought to demodulation and information recovery of the received signals. Therefore, for rocket-borne communications, a highly reliable transmission method under the condition of a power-limited channel needs to be found, and a high-gain channel code is an effective solution. The high-gain channel code can obtain considerable channel gain through an excellent coding and decoding algorithm design, effectively reduces a signal demodulation threshold, and further counteracts energy loss brought by signals in a long-distance space transmission process. For this purpose, CCSDS establishes a series of channel code standards including convolutional codes, RS codes, concatenated codes, TURBO codes, LDPC codes, and the like.

The CCSDS architecture has recently attracted more and more attention from military organizations of various countries in the world due to its characteristics of excellent performance, good economic benefit, wide adaptability and the like. Due to the universality of the CCSDS framework, the CCSDS framework is applied to the military field without much technical change, so that the research on how the CCSDS framework is implemented in the military aerospace field has important significance for improving the efficiency of military spacecrafts and promoting the development of military and civil integration industries and the technical progress of military aerospace.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a flight image decoding method and system based on a CCSDS (consultative committee for space data system) architecture.

In a first aspect, the present invention provides a method for decoding a flying image based on a CCSDS architecture, including:

step 1: forwarding the image compression code stream of the aircraft in the flight process to an image processor through a telemetering ground station; the image compressed code stream generated by the aircraft side is transmitted to the telemetering ground station according to a CCSDS standard channel code;

step 2: and the image processor decodes the image compressed code stream to obtain decoded image data.

In the embodiment, a CCSDS framework is adopted to set a series of recommendation standards for a spatial data system consultation committee for remote control and remote measurement in deep space flight communication and an advanced on-orbit system (AOS). The channel characteristics of the channel code determine that the channel code has high reliability on aircraft flight communication under the condition of low signal-to-noise ratio.

In one possible design, the step 1 includes:

the remote measuring ground station sends the image compression code stream to the image processor through a UDP multicast protocol; the image compression code stream comprises: channel identification, a pilot header and a data field; wherein the content of the first and second substances,

the channel identification is used for calling the control logic of the corresponding state according to the state parameter;

the master header is used to provide a frame: any one or more of a version number, a spacecraft identifier, a virtual channel frame counter;

the data field is used for recording an engineering telemetry source packet, a data transmission data frame and an idle data frame; the data transmission frame includes: surveillance camera image data, GNSSB raw measurement data, and backup data.

In one possible design, the step 2 includes:

sequentially extracting data transmission frames in a data domain according to a virtual channel identifier in a main header provided by a CCSDS (consultative committee for space data system) architecture, and storing the data transmission frames as data streams;

and decoding the image data frames with different lengths in the data stream according to the value of the virtual channel counter provided by the CCSDS framework to obtain decoded image data.

In this embodiment, the CCSDS code stream extraction module in the image processor cyclically reads a frame of data from the cache, where the data is encapsulated after the ground-based device receives the telemetry aircraft flight image code stream. And a CCSDS code stream decoding module in the image processor decodes and restores each frame of image data with different lengths into image data of an image frame sequence.

In one possible design, further comprising:

and step 3: and playing the decoded image data.

In this embodiment, the image processor is loaded with decoding software, and when the decoding software is run, the image can be analyzed and played in real time, and the delay time is not more than 3 s. Therefore, the image processor can directly read the playable file stored locally and directly play the video.

In one possible design, the step 3 includes:

displaying the decoded image data on one or more displays;

and adjusting the size and/or the display time length of a display frame on any display.

In this embodiment, the decoding software loaded in the image processor may set a single or multiple frames to play the surveillance camera video simultaneously, and the size of the display frame may be manually adjusted, and may display the current image playing time.

In a second aspect, the present invention provides a flying image decoding system based on a CCSDS architecture, including: a telemetric ground station and an image processor communicatively coupled; wherein:

the telemetering ground station is used for forwarding the image compression code stream of the aircraft in the flight process to the image processor;

and the image processor is used for decoding the image compression code stream to obtain decoded image data.

In one possible design, the telemetry ground station is specifically configured to:

sending the image compressed code stream to the image processor through a UDP multicast protocol; the image compression code stream comprises: channel identification, a pilot header and a data field; wherein the content of the first and second substances,

the channel identification is used for calling the control logic of the corresponding state according to the state parameter;

the master header is used to provide a frame: any one or more of a version number, a spacecraft identifier, a virtual channel frame counter;

the data field is used for recording an engineering telemetry source packet, a data transmission data frame and an idle data frame; the data transmission frame includes: surveillance camera image data, GNSSB raw measurement data, and backup data.

In one possible design, the image processor is specifically configured to:

sequentially extracting data transmission frames in a data domain according to a virtual channel identifier in a main header provided by a CCSDS (consultative committee for space data system) architecture, and storing the data transmission frames as data streams;

and decoding the image data frames with different lengths in the data stream according to the value of the virtual channel counter provided by the CCSDS framework to obtain decoded image data.

In one possible design, further comprising:

and the display is used for receiving and playing the decoded image data.

In one possible design, the display is further configured to: and adjusting the size of the display picture and/or the display time length.

Compared with the prior art, the invention has the following beneficial effects:

according to the flight image decoding method and system based on the CCSDS framework, the image compression code stream of the aircraft in the flight process is forwarded to the image processor through the telemetering ground station; the image compressed code stream generated by the aircraft side is transmitted to the telemetering ground station according to a CCSDS standard channel code; and the image processor decodes the image compressed code stream to obtain decoded image data. Therefore, the reliability and timeliness of decoding the flight images of the aircraft can be effectively improved, and the quality of the decoded images is improved.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

fig. 1 is a schematic diagram of an application scenario provided in an exemplary embodiment of the present invention;

fig. 2 is a schematic diagram illustrating an image compressed code stream format of a CCSDS protocol according to an exemplary embodiment of the present invention;

FIG. 3 is a diagram illustrating a compressed image format based on the CCSDS protocol according to an exemplary embodiment of the present invention;

fig. 4 is a schematic diagram of a decoding software configurable picture according to an exemplary embodiment of the present invention.

Detailed Description

The present invention will be described in detail with reference to specific examples. The following examples will assist those skilled in the art in further understanding the invention, but are not intended to limit the invention in any way. It should be noted that it would be obvious to those skilled in the art that various changes and modifications can be made without departing from the spirit of the invention. All falling within the scope of the present invention.

The flight image decoding method and system based on the CCSDS framework can be widely applied to the field of deep space exploration of rockets, airships, hot air balloons and the like.

Fig. 1 is a schematic diagram of an application scenario provided in an exemplary embodiment of the present invention; as shown in fig. 1, may include: the aircraft 10 sends downlink data (namely an image compressed code stream of the aircraft during flight) to the telemetry ground station 20, and the downlink data is transmitted to the telemetry ground station 20 according to a CCSDS standard channel code. The telemetering ground station 20 sends the downlink data to the image processor 30 through the LAN, and the image processor 30 decodes the downlink data to obtain a decoded image code stream. Finally, the image code stream is played on the launched one or more displays 40.

In this embodiment, the image processor 30 includes at least one physical interface, and a communication protocol and/or a bottom layer driver are disposed in the interface to adapt to different data input devices. Optionally, the image processor 30 is connected to the telemetry ground station 20 via a LAN network. The telemetry ground station 20 sends the processed image compression code stream to the image processor 30 by using a UDP multicast protocol. After receiving the image compression code stream, the image processor 30 calls a code stream extraction module to work by using the loaded image processing software. Specifically, the method comprises the steps of firstly judging a virtual channel identifier in an image compression code stream format, distinguishing monitoring camera image A data, monitoring camera image B data or other monitoring cameras; after the code stream extraction is finished, independently decoding the two/multi-path monitoring camera foundation telemetering format, and judging the 'virtual channel count' of the image compression code stream format. Meanwhile, a 'playback mark' of the image compression code stream format is judged to distinguish a real-time image from a delayed image, and the delayed image is not displayed but only stored.

Illustratively, the image processor 30 parses the decoded video stream and connects the parsed video stream to a base IPTV (internet Protocol Television) system through a standard VGA channel.

By applying the rocket flight image decoding method based on the CCSDS framework, the problem that the rocket flight image application industry lacks an efficient and reliable framework protocol can be solved.

The present application is further described below in conjunction with fig. 2-4. Referring to fig. 2, fig. 2 is a schematic diagram of an image compressed code stream format of a CCSDS protocol according to an exemplary embodiment of the present invention. The CCSDS architecture data protocol of this embodiment includes a 4 byte synchronization identifier, a 6 byte leading header, a 1012byte data field, and a 2byte CRC check. The frame format adopts the data frame format suggested by CCSDS, and each frame has a total length of 1024 bytes. The specific frame structure is shown in table 1.

Table 1 picture compression bitstream frame structure

And (3) synchronous identification: in the specific embodiment of the present invention, 1ACFFClDH is fixed.

A main guide head: the master header in the embodiment of the present invention is specifically shown in table 2. The master header is used to provide a frame version number, a spacecraft identifier, a virtual channel frame counter, etc. And the data field is used for recording the engineering telemetry source packet, the data transmission data frame and the idle data frame. The data transmission frame comprises monitoring camera image data, GNSSB original measurement data, standby and other external 5-path data transmission data, and the data transmission data corresponds to corresponding virtual channels respectively.

Table 2 picture compression bitstream frame preamble

The length of the image compression code stream domain is 1012Byte in the embodiment of the invention, and the image compression code stream domain is used for filling three types of data frames: the data transmission system comprises an engineering telemetry source packet, a data transmission data frame, a GNSSB original measurement data frame and a standby channel data frame.

The data transmission data frame comprises monitoring camera image data, GNSSB original measurement data, standby and other external 5-path number transmission data, and the data transmission data frame corresponds to the virtual channel identifiers in the corresponding table 3 respectively.

Table 3 picture compression bitstream frame virtual channel identifier

The virtual channel identifier of the image compression code stream frame is used for calling the control logic of the corresponding state according to the state parameter, and occupies 4 bytes (32 bits).

With reference to fig. 3, the compressed image of the surveillance camera according to the embodiment of the present invention is composed of a 16-byte header and an image information data encoded by h.264 with variable length. The 16-byte packet header comprises a 4-byte frame identifier, a 4-byte frame count, a 4-byte time code, a 3-byte frame length and a 1-byte encoding type; the image information data is composed of an indefinite length image information byte and a 1-byte image NAL header leading header.

The actual operation flow of the specific embodiment of the invention is as follows:

and step S10l, uniformly framing and packaging image data source codes generated by the monitoring camera A/B according to a ground-based telemetry format, and then descending to a ground station.

And step S102, the ground station receives the downlink image compressed code stream frame and sends the downlink image compressed code stream frame to the image processor through the LAN port.

Step S103, the ground image processing display software running on the image processor receives the image compression code stream, firstly, a code stream extraction module of the image processing software identifies a virtual channel frame counter in a main guide head, and sequentially extracts the image data code stream according to the sequence of the frame counter. And the extracted data code stream is forwarded to a code stream decoding module, the code stream decoding module starts to decode the image data of the monitoring camera A by identifying the virtual channel identifier, and if the virtual channel identifier is 000010. Similarly, if the virtual channel identifier is 000011, the code stream decoding module starts to decode the image data of the monitoring camera B.

In step S104, the multi-channel image data may be asynchronously parsed in real time.

And step S105, sending the decoded image data to an image monitor through a VGA interface for display.

The image processor provided by the application adopts an industrial personal computer as a basis, develops image processing application software and is provided with an image monitor.

The method adopts the multi-channel image data asynchronous decoding display technology, combines the figure 4, realizes the simultaneous decoding display of the multi-interface image data on the same software interface, and can configure the functions of the simultaneous display of the multi-channel images, the amplification and the reduction of the images and the playback of the images.

In an exemplary embodiment, an image receiving card, an image processing industrial personal computer and an image monitor are arranged in the image processor.

The image receiving card is responsible for completing specific image compression code stream receiving and storing the received code stream to the image processing industrial personal computer.

The image processing industrial personal computer is responsible for providing hardware bases for image compression code stream storage, image data decoding processing and image output. And the image processor software runs on the image processing industrial personal computer.

The image monitor is responsible for displaying decoded image data output by the image processing industrial personal computer.

The embodiment also provides the standby equipment which has the same components and connection modes as the original equipment, and when the original equipment cannot work normally, the standby equipment can be switched to quickly, so that the stability of image display in the rocket flight process is effectively ensured.

The flight image decoding method based on the CCSDS framework improves the image decoding efficiency and the stability and the real-time performance of image display in the rocket flight process.

It should be noted that, the steps in the method for decoding a flight image based on a CCSDS architecture provided in the present invention may be implemented by using corresponding modules, devices, units, and the like in the system for decoding a flight image based on a CCSDS architecture, and those skilled in the art may refer to the technical solution of the system to implement the step flow of the method, that is, the embodiment in the system may be understood as a preferred example for implementing the method, and will not be described herein again.

Those skilled in the art will appreciate that, in addition to implementing the system and its various devices provided by the present invention in purely computer readable program code means, the method steps can be fully programmed to implement the same functions by implementing the system and its various devices in the form of logic gates, switches, application specific integrated circuits, programmable logic controllers, embedded microcontrollers and the like. Therefore, the system and various devices thereof provided by the present invention can be regarded as a hardware component, and the devices included in the system and various devices thereof for realizing various functions can also be regarded as structures in the hardware component; means for performing the functions may also be regarded as structures within both software modules and hardware components for performing the methods.

The foregoing description of specific embodiments of the present invention has been presented. It is to be understood that the present invention is not limited to the specific embodiments described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention. The embodiments and features of the embodiments of the present application may be combined with each other arbitrarily without conflict.