CN113093259B

CN113093259B - On-orbit gamma ray storm opportunity target observation method

Info

Publication number: CN113093259B
Application number: CN202110417622.4A
Authority: CN
Inventors: 贺俊旺; 陈琨; 苏斌嫔; 苏瑞丰; 毛青筠; 李飞; 张晓峰
Original assignee: Shanghai Engineering Center for Microsatellites; Innovation Academy for Microsatellites of CAS
Current assignee: Shanghai Engineering Center for Microsatellites; Innovation Academy for Microsatellites of CAS
Priority date: 2021-04-19
Filing date: 2021-04-19
Publication date: 2023-04-21
Anticipated expiration: 2041-04-19
Also published as: CN113093259A

Abstract

The invention provides an on-orbit gamma ray storm opportunity target observation method, which is used for performing opportunity observation on a new discovery source, a known temporary active source or a known temporary variable source, wherein in the operation process of an astronomical observation satellite, after astronomical events occurring in the universe are monitored by other satellites, an observation task plan is formed after the astronomical observation satellite is analyzed by a ground station, and the observation task plan is uploaded to the astronomical observation satellite so that the astronomical observation satellite executes an observation task; the observation task planning comprises conventional opportunity target observation, important opportunity target observation and multi-messenger opportunity target observation; the importance of the observation object of the important opportunity object observation and the multi-messenger opportunity object observation is higher than that of the observation object of the conventional opportunity object observation; the priority of the important opportunity target observation and the multi-messenger opportunity target observation is higher than that of the conventional opportunity target observation; the observation object of the multi-messenger opportunity object observation is larger than the observation objects of the important opportunity object observation and the conventional opportunity object observation.

Description

On-orbit gamma ray storm opportunity target observation method

Technical Field

The invention relates to the technical field of space observation, in particular to an on-orbit gamma ray storm opportunity target observation method.

Background

Gamma Ray storm (abbreviated as GRB), which is a phenomenon in which the intensity of Gamma rays from a certain direction in the sky is suddenly increased in a short time and then rapidly decreased for a duration of 0.1-1000 seconds, the radiation is mainly concentrated in an energy band of 0.1-100 MeV. The gamma storm was found in 1967, the nature of which was not well understood for decades, but it was basically determined that the process of outbreaks occurred in stars-level celestial bodies on a cosmic scale. Gamma storms are one of the most active areas of research in astronomy at present, and have been evaluated by the journal of science in the united states as ten technological advances in the year in 1997 and 1999.

Gamma ray storm is the strongest shot phenomenon in the currently known universe, and is theoretically generated by collapse explosion of a huge star when fuel is consumed or by merging two adjacent compact stars (black holes or neutron stars). Gamma rays are as short as one thousandth of a second and as long as several hours, and release huge energy in a short time. If its energy released in a few minutes is equivalent to the sum of trillion years of sunlight as compared to the sun, its emitted single photon energy is typically hundreds of thousands times that of typical sunlight.

The energy mechanism of gamma ray exposure remains far unsolved so far, which is also a core problem in gamma ray exposure research. With the advancement of technology, people will get more deeply aware of the universe, many of the now seemingly puzzle problems may be solved in the future, and not only the need for humans to pursue scientific progress, but also the resolution of these puzzles will ultimately benefit themselves. How to find, locate and measure various gamma ray storms to study the evolution of universe and dark energy is a difficult problem in astronomy field at present.

Disclosure of Invention

The invention aims to provide an on-orbit gamma ray storm target observation method which aims to solve the problem that the existing gamma ray storm observation difficulty is high.

In order to solve the above technical problems, the present invention provides an on-orbit gamma ray storm opportunity target observation method, which performs opportunity observation on a new discovery source, a known temporary active source or a known temporary variable source, comprising:

in the operation process of the astronomical observation satellite, after astronomical events occurring in the universe are monitored by other satellites, an observation task plan is formed after the astronomical events are analyzed by a ground station, and the observation task plan is uploaded to the astronomical observation satellite so that the astronomical observation satellite executes an observation task;

the observation task planning includes:

the multi-messenger opportunity object observation is conducted in a multi-directional and spliced observation mode, the observation object is divided into a plurality of pieces, and observation path planning is conducted according to the priority and maneuvering angle of each piece, so that the astronomical observation satellite observes the plurality of pieces of objects.

Optionally, in the method for observing an on-orbit gamma ray storm opportunity target, the frequency of observation of the multi-messenger opportunity target is expected to be 1 time per week;

the observation duration of the observation of the multi-messenger opportunity targets is not more than 14 tracks, the number of the targets observed in the single track is not more than 5, and the observation time of each target is 10 minutes;

during normal operation of the astronomical observation satellite, 5 targets were selected within 10 x 10 within a single track,

during extended operation of astronomical observation satellites, 10×10 ° was no longer constrained.

Optionally, in the on-orbit gamma ray storm opportunity target observation method, the observation task plan further includes conventional opportunity target observation and important opportunity target observation;

the importance of the observation object of the important opportunity object observation and the multi-messenger opportunity object observation is higher than that of the observation object of the conventional opportunity object observation;

the priority of the important opportunity target observation and the multi-messenger opportunity target observation is higher than the priority of the conventional opportunity target observation;

the observation object of the multi-messenger opportunity object observation is larger than the observation objects of the important opportunity object observation and the regular opportunity object observation.

Optionally, in the on-orbit gamma ray storm opportunity target observation method, the priority of the conventional opportunity target observation is lower than that of the gamma storm observation and the reproduction source observation and higher than that of the conventional observation, and the priority of the important opportunity target observation and the multi-messenger opportunity target observation is higher than that of the gamma storm observation and the reproduction source observation;

the gamma storm observation includes:

after a gamma ray storm is detected through high-energy load with a wide field of view, an astronomical observation satellite is triggered to acquire the position parameter, the energy spectrum parameter and the light variation parameter of the gamma ray storm, and the position parameter, the energy spectrum parameter and the light variation parameter are provided for a ground station in real time through a VHF (very high frequency) band;

the astronomical observation satellite performs autonomous and rapid attitude maneuver according to the triggering information of the gamma ray storm positioned by the high-energy load, and performs continuous observation of optical afterglow on the gamma ray storm;

in observation, the astronomical observation satellite keeps high attitude stability, and the detection performance of the optical telescope is ensured.

Optionally, in the method for observing the on-orbit gamma ray storm opportunity target, during the normal operation of the astronomical observation satellite, the astronomical observation satellite performs normal opportunity target observation once a day, wherein the normal opportunity target observation accounts for 15% of the effective time of all observations;

during the expanding operation period of the astronomical observation satellite, the astronomical observation satellite performs five conventional opportunity target observations every day, wherein the conventional opportunity target observations account for more than 40% of the effective time of all observations;

and (5) carrying out calibration test of the load instrument by using conventional opportunity target observation.

Optionally, in the on-orbit gamma ray storm opportunity target observation method, the expected frequency of the important opportunity target observation is 1 time per month.

Optionally, in the method for observing an on-orbit gamma ray exposure opportunity target, the on-orbit gamma ray exposure opportunity target observation direction includes: the included angle between the sun and the +Xs axis of the astronomical observation satellite is larger than 90 degrees, so that the +X plane of the astronomical observation satellite is not irradiated by the sun;

the included angle between the sun and the +Y plane of the astronomical observation satellite or the-Y plane of the astronomical observation satellite is smaller than 5 degrees;

the included angle between the sun and the-Zs axis of the astronomical observation satellite is larger than 90 degrees, so that the-Z plane of the astronomical observation satellite is not irradiated by the sun.

Optionally, in the on-orbit gamma ray exposure opportunity target observation method, the observation tasks of the conventional opportunity target observation include a conventional opportunity gamma exposure revisit target task, a conventional opportunity supplementary calibration target task and a conventional opportunity celestial object task;

the observation flow of the on-board conventional opportunity target observation comprises the following steps:

a ground station is injected with one day of conventional opportunity target observation tasks, wherein the conventional opportunity target observation tasks comprise 1-5 observation tasks, and each observation task comprises a conventional opportunity target observation platform task package and a load configuration table;

task starting time, the star computer carries out constraint judgment according to task mode constraint; if all constraints pass, the satellite maneuvers to point to the target and synchronously broadcasts the current task ID;

the satellite is powered up, and the sailboard is rotated according to the sailboard rotation strategy;

the load data processing computer configures VT working parameters according to the current task ID, the conventional opportunity target observation platform task package and the load configuration table;

the high energy load remains in the current mode.

Optionally, in the on-orbit gamma ray storm opportunity target observation method, the important opportunity target observation includes immediately executing a task and delaying execution of the task, wherein:

the observation flow of the on-board important opportunity target observation is as follows:

the ground station is provided with 1 important opportunity target observation task, including an important opportunity target observation platform task package and a load configuration table;

according to time parameters in the important opportunity target observation platform task package, the star computer immediately or according to a set time point, carries out constraint judgment according to task mode constraint;

if all constraints pass, the satellite maneuvers to point to the target and synchronously broadcasts the current task ID;

the load data processing computer configures VT working parameters according to the current task ID, the important opportunity target observation platform task package and the load configuration table;

the high energy load remains in the current mode;

the newly-uploaded important opportunity target observation can interrupt the current important opportunity target observation task.

Optionally, in the on-orbit gamma ray storm opportunity target observation method, an observation flow of on-board multi-messenger opportunity target observation is as follows:

injecting a multi-messenger opportunity target observation task on the ground, wherein the multi-messenger opportunity target observation task comprises a multi-messenger opportunity target observation platform task package and a load configuration table;

when a certain sheet starts, constraint judgment is carried out according to task mode constraint conditions;

the current task is kept if the current constraint is not passed;

when the next sheet starts, continuing constraint judgment according to the constraint condition of the task mode;

if all the constraints of all the slices pass, the satellite maneuvers, points to the target and synchronously broadcasts the current task ID;

the load data processing computer configures VT working parameters according to the current task ID, the task package of the multi-messenger opportunity target observation platform and the load configuration table, and generates a VHF data package observed by the multi-messenger opportunity target;

the high energy load remains in the current mode;

continuing the steps after the start time of the transfer until all the pieces are executed;

the newly-uploaded multi-messenger opportunity target observation can interrupt the current important opportunity target observation task.

In the method for observing the on-orbit gamma ray storm opportunity target, provided by the invention, the new discovery source, the known temporary active source or the known temporary variable source is subjected to opportunistic observation, in the operation process of an astronomical observation satellite, after astronomical events occurring in the universe are monitored by other satellites, an observation task plan is formed after the astronomical observation satellite is analyzed by a ground station, the observation task plan is uploaded to the astronomical observation satellite, so that the astronomical observation satellite executes the observation task, and the observation task plan comprises different priorities and different observation target sizes which are divided into a plurality of observations, so that the flexibility of the observation can be improved, and the persistence, the accuracy and the reliability of the gamma ray storm observation are improved.

In addition, the astronomical observation satellite achieves the advantage of high autonomous capacity on the satellite through the characteristics of rapid maneuvering of the satellite, autonomous management on the satellite and the like, and solves the problem of complex task mode. Besides the ground planning task, the ground planning task and the on-orbit autonomous triggering task are coordinated with each other on a plurality of on-orbit autonomous observation tasks, and the on-orbit cooperative management of the ground planning task and the on-orbit autonomous triggering task is realized.

Drawings

Fig. 1 (a) is a schematic diagram of an observation target for a to-MM observation of GW170814 according to an embodiment of the present invention;

FIG. 1 (b) is a schematic diagram of a ToO-MM observation implementation performed by GW170814 according to an embodiment of the present invention;

FIG. 2 is a schematic view of an embodiment of the present invention with opposite sun directions;

FIG. 3 is a schematic diagram showing the relative relationship between sun and satellite under the orientation of an embodiment B1 of the present invention;

FIG. 4 is a diagram of a field of view trajectory of an ECLAIRs with an embodiment B1 of the present invention pointing downward;

FIG. 5 is a graph showing the variation of solar and-Xs axis angles according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of GRB observation orientation in accordance with one embodiment of the invention;

FIG. 7 is a schematic diagram of an on-board task management flow according to an embodiment of the invention;

FIG. 8 is a schematic diagram of an on-board task switch flow according to an embodiment of the invention.

Detailed Description

The method for observing the target of the on-orbit gamma ray storm provided by the invention is further described in detail below with reference to the accompanying drawings and the specific embodiments. Advantages and features of the invention will become more apparent from the following description and from the claims. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.

In addition, features of different embodiments of the invention may be combined with each other, unless otherwise specified. For example, a feature of the second embodiment may be substituted for a corresponding feature of the first embodiment, or may have the same or similar function, and the resulting embodiment would fall within the disclosure or scope of the disclosure.

The invention provides an on-orbit gamma ray storm opportunity target observation method, which aims to solve the problem of high difficulty in the existing gamma ray storm observation.

In order to achieve the above-mentioned idea, the present invention provides an on-orbit gamma ray storm opportunity target observation method, which performs opportunity observation on a new discovery source, a known temporary active source or a known temporary variable source, comprising: in the operation process of the astronomical observation satellite, after astronomical events occurring in the universe are monitored by other satellites, an observation task plan is formed after the astronomical events are analyzed by a ground station, and the observation task plan is uploaded to the astronomical observation satellite so that the astronomical observation satellite executes an observation task; the observation task planning comprises conventional opportunity target observation, important opportunity target observation and multi-messenger opportunity target observation; the importance of the observation object of the important opportunity object observation and the multi-messenger opportunity object observation is higher than that of the observation object of the conventional opportunity object observation; the priority of the important opportunity target observation and the multi-messenger opportunity target observation is higher than the priority of the conventional opportunity target observation; the observation object of the multi-messenger opportunity object observation is larger than the observation objects of the important opportunity object observation and the regular opportunity object observation.

The invention adopts astronomical observation satellites to find and locate, measures various Gamma-Ray Burst (GRB) and other high-energy transient phenomena (including X-Ray Burst, soft Gamma repeated Burst, active star nucleus AGN, novacell and the like), and researches the evolution and dark energy of universe. The satellite has the characteristics of autonomous on-board discovery of targets, rapid maneuvering of the satellite, autonomous on-board management and the like, and is one of the satellites with highest requirement on autonomous on-board capability and most complex task mode at present. Besides the autonomous observation task on the satellite, the on-satellite automatic triggering system also has various ground planning tasks, and the on-satellite ground planning tasks and the on-orbit autonomous triggering tasks are required to be cooperatively managed.

The invention designs a plurality of on-orbit observation modes according to the system requirement, wherein the on-orbit observation modes comprise four major categories of gamma storm observation (GRB), reproduction source observation (Catalog transient event, CAT), general Program (GP) and opportunity target (Target of Opportunity, toO) observation, and the ToO observation comprises conventional opportunity target (Nominal Target of Opportunity, toO-NOM) observation, important opportunity target (Exceptional Target of opportunity, toO-EX) observation and Multi-messenger opportunity target (Multi-messenger Target of opportunity, toO-MM) observation.

The narrow field of view load includes the soft X-ray telescope MXT and the optical telescope VT, and the wide field of view load includes the hard X-ray camera ECLAIRs and the gamma ray monitor GRM.

Due to uncertainty of autonomous observation timing, target direction and the like on the satellite, the ground station cannot predict the current in-orbit observation mode, attitude direction, energy and the like of the satellite. In order to ensure the safety of the load and the satellite and the validity of scientific data, a plurality of constraint conditions such as solar constraint, moon constraint, energy constraint and the like are calculated and judged before a new observation task is executed. Therefore, the on-orbit observation mode and the autonomous management are key to success and failure of satellite observation tasks.

The astronomical observation satellite in-orbit observation mode comprises GRB, CAT, GP and ToO observation tasks, wherein GP observation is a pre-planned observation of a known source or a sky, and ToO observation task is an opportunity observation of a new discovery source or a known temporary active source/variable source. GRB and CAT are on-board autonomous triggering tasks for gamma storm observation.

In one embodiment of the present invention, a GRB observation requirement is provided, GRB observation is a main task of an astronomical observation satellite, and GRB observation can be completed by on-board and ground cooperation observation or on-board independent triggering, and on-board main works include: the satellite detects the triggering of the gamma storm through the wide view field load, obtains the parameters of the position, the energy spectrum, the light variation and the like of the detected gamma storm, and provides the parameters to the ground in near real time through the VHF wave band; the satellite performs autonomous and rapid attitude maneuver according to the gamma storm triggering information positioned by the wide field of view load, and performs continuous observation of optical afterglow on the gamma storm; the satellite keeps high attitude stability (0.8'/100 s) and ensures the detection performance (22.5 Mv) of the optical telescope; the satellite can observe according to GRB observation time length set on the satellite, and defaults to continuously observing 14 tracks. At least 200 gamma storms of various types are expected to be detected and located during astronomical observation satellite missions, including: short storms (duration of a few milliseconds to 1-2 seconds), long storms (duration of up to 1,000 seconds), gamma storms that are particularly rich in X-rays (e.g., gamma storms where the radiation is predominantly below an energy band of 30 keV).

In one embodiment of the invention, a CAT observation requirement is provided, the CAT observation is very similar to the GRB observation, the main difference is that a known gamma storm information list is stored in a CAT observation wide field load, once a gamma storm target source is found and positioned successfully, the wide field load is compared with the stored list, if the detected target is the stored target, the CAT observation is adopted at the time, and otherwise, the GRB observation is adopted at the time. The rest of the processing flows on the satellite are consistent with GRB observations. The contents of the gamma storm information list (the observation source and the corresponding threshold) are continually updated during the task.

In one embodiment of the invention, GP observation requirements are set forth, GP observations being ground planning tasks awaiting GRB triggering. The GP observation planning is directed to facilitate the discovery of gamma storms, with the observation covering the entire observation period seamlessly. GRB or ToO observations can interrupt GP observations. After GRB or ToO observation is finished, the maneuver is returned and the observation which should be originally executed at the current moment in the GP observation task is executed. Calibration testing of the load instrument is also one type of GP observation. During normal operation of the satellite (within 3 years of the checking life), the GP task occupies at least 60% of the total overall observation effective time. During satellite extended operation (beyond 3 years of life), GP mission is reduced to 35%.

In one embodiment of the invention, there is a proposed to observe the need for a ToO observation, which is an observation-worthy astronomical event that suddenly occurs in the universe during the operation of a satellite, which can be found by other satellites, analyzed by scientists, planned by ground stations, and uploaded to the observation tasks performed by the satellites. ToO observations are divided into three subclasses, regular opportunity target (ToO-NOM) task observations, important opportunity target (ToO-EX) task observations, and multi-messenger opportunity target (ToO-MM) task observations.

The ToO-NOM observation is an astronomical emergency event which is important, and can be interrupted by GRB observation. The ToO-NOM observation also supports calibration testing of the load instrument. Second, the ToO-EX observations are very important astronomical events or targets, which have very strong observation value, and during the observation period, satellites do not respond to GRBs detected on the satellites. The expected frequency of such opportunity targets is 1 per month. Finally, the ToO-MM observation object is also an important astronomical event or object, but the object is large and cannot be covered by one-time observation, so the multi-directional and spliced observation mode is designed, the object is divided into a plurality of pieces (tiles), and a path is reasonably planned according to priority, maneuvering angle and the like, so that the observation of the object is realized.

Fig. 1 (a) shows an observation target, fig. 1 (b) shows that the observation target is divided into a plurality of tiles according to the ToO-MM observation requirement, and according to a target planning algorithm given by a system, 5 tiles are selected from each track within a range of 10 degrees x 10 degrees in consideration of factors such as priority and view field, and each tile realizes effective observation time of about 10 minutes. ToO-MM observations during the expansion test can be unconstrained for 10. Times.10.

The invention also provides a plurality of observation orientations in an in-orbit observation mode, mainly comprising GP orientation, toO orientation and GRB/CAT orientation during astronomical observation satellite observation, wherein the orientations all have to meet the requirement of anti-sun orientation, and as shown in figure 2, mainly comprise: the included angle between the sun and the +Xs axis is larger than 90 degrees, so that the +X plane is not irradiated by the sun; the included angle between the sun and the +Y plane or the-Y plane is smaller than 5 degrees; the included angle between the sun and the-Zs axis is larger than 90 degrees, so that the-Z plane is not irradiated by the sun.

In one embodiment of the invention, GP pointing is proposed, with GP observation pointing typically within ±10° of the satellite reference pointing (i.e. "B1 pointing") optimized for gamma storm detection, while the field of view of the narrow field-of-view instrument is not obscured by the earth. B1 is directed by adopting an optimized reverse sun pointing scheme, as shown in fig. 3, the reverse sun pointing can ensure that the detected gamma storm is positioned at one side of the earth shadow, so that the ground telescope can observe at night, and the following factors are required to be considered specifically on the basis of reverse sun: avoiding special sky areas such as ScoX-1, galaxy strips and the like which have influence on GRB detection; ensuring that the observed sky is beneficial to the observation of the ground large telescope; provides a good thermal environment for the load, so that the load is not influenced by the sun before and after the attitude maneuver. According to the distribution of the ground big telescope, the satellite pointing should be as close to the equator as possible, if the declination of the pointing is between [ -21 °, +25 ° ], all three big telescopes have the opportunity to observe the detected gamma storm. B1 points down the wide field load field edge trajectory as shown in FIG. 4. As can be seen from fig. 4, the wide field load field of view well avoids the silvery band and Scox1 bright celestial body during operational observations. The rotation of the satellite about the Xs axis is required to satisfy the solar and satellite relationship, and the resulting rotation of the field of view edge can be seen from the figure. The sun is at an angle of 45 deg. to the + Z plane, which in some special cases may be up to 62 deg. due to the avoidance of Scox1 from the Galaxy, as shown in FIG. 5. To introduce GP observation planning flexibility, it is also defined that the proportion exceeding the reference direction ±10° increases continuously with the observation time, exceeding the proportion by about 10% during normal operation of the item, gradually increasing to 50% during expansion.

In one embodiment of the invention, a ToO pointing is proposed, and the ToO observation need not follow the reference pointing, only the anti-sun pointing needs to be guaranteed.

In one embodiment of the invention, GRB pointing/CAT pointing is proposed, with GRB events randomly occurring anywhere within the wide field load field of view, with the angle of maneuver being at most +/-45 deg. when viewed. This orientation after maneuver is referred to as the GRB orientation, as shown in FIG. 6.

The invention also provides a management method of the on-orbit observation mode, which specifically comprises the overall design of the observation mode, and the on-satellite observation is realized by combining an SMU (Satellite Management Unit, a satellite-borne computer) and a PDPU (Payload Data Processing Unit, a load data processing computer) according to the observation requirement, and the specific flow is shown in figure 7. As can be seen from fig. 7, the on-board observation tasks are managed by the SMU and the PDPU, and the PDPU mainly manages the on-board triggered tasks, and the SMU comprehensively manages the ground planning and the on-board autonomous triggered observation tasks.

In one embodiment of the present invention, observation mode switching management is presented, and fig. 8 shows various observation mode switching diagrams. The management flow of the ground planning task is as follows: the ground station sends the GP and ToO platform task list to be stored in the SMU; the load configuration tables corresponding to GP and ToO tasks sent by the ground station are stored in the PDPU; when the task starts, the SMU performs constraint judgment according to the constraint condition of the task mode; if all constraints pass, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; the PDPU configures load working parameters according to the task ID and the setting in the load configuration table; and rotating the sailboard according to the sailboard rotation strategy. The current direction is kept, and the next task is waited.

In one embodiment of the present invention, an on-board autonomous triggering management flow is proposed as follows: the PDPU receives the wide-view-field load trigger packet in real time and forwards the wide-view-field load trigger packet to the ground station through a VHF channel; the PDPU judges a maneuvering request mark in the wide-field-of-view load triggering package, when the maneuvering request is effective, the PDPU calculates the included angles (solar constraint and moon constraint) between the target orientation and the sun and the moon according to the position information in the wide-field-of-view load triggering package, and judges whether the target is suitable for satellite observation. And when the solar constraint and the moon constraint are passed, the PDPU converts the target orientation into a gesture quaternion and sends the gesture quaternion to the SMU. The subsequent SMU processing flow comprises: when the task starts, the SMU judges according to the constraint condition of the task mode; if all constraints pass, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; the PDPU configures load working parameters according to the current task ID and the settings in the load configuration table; and rotating the sailboard according to the sailboard rotation strategy. The current direction is kept, and the next task is waited. The task mode constraint conditions comprise priority, solar constraint, moon constraint, energy constraint and sailboard rotation strategy which are higher than those of the current on-orbit observation mode.

The invention also provides an observation constraint design and management method, which comprises attitude maneuver constraint, wherein when a task is responded, an astronomical observation satellite needs maneuver and points to a target, and in the process, other task interrupt requests are not responded. Priority management is also included, and the priorities of various tasks (in-orbit observation modes) of the astronomical observation satellite are from low to high according to the requirements and the definition of the system: GP task < ToO-NOM task < GRB/CAT task < ToO-EX task/ToO-MM task; it can be seen that the task priority is the lowest GP task, the GRB and CAT tasks are the same priority, the ToO-EX task and the ToO-MM task are the same priority, the priority is highest, and the GRB and CAT tasks can be interrupted. The newly added ToO-EX task and ToO-MM task may interrupt the original ToO-EX task and ToO-MM task.

Specifically, the astronomical observation satellite performs two sun constraint and moon constraint checks on all tasks. For GP and ToO tasks, the ground is checked tightly in advance, and the confirmation comprises solar constraint and moon constraint through re-filling. For the GRB task and the CAT task, PDPU is adopted to firstly carry out tight inspection and confirm that solar constraint and moon constraint pass and then forward the solar constraint and the moon constraint to the SMU. The SMU checks sun and moon constraints as required for all task requests.

In one embodiment of the present invention, solar constraint is proposed, and the PDPU needs to determine that the solar-satellite included angle needs to satisfy: angle 1[ sun, satellite+x axis ] >91.1 °; the SMU judges that the included angle of the solar constraint needs to be satisfied: the angle is 1[ sun, satellite+X axis ] >89.9 degrees, the angle is 2[ sun, satellite+Y axis ] >85 degrees, the angle is 3[ sun, satellite-Y axis ] >85 degrees, and the angle is 4[ sun, satellite-Z axis ] >89 degrees. The above parameters support ground instruction modification parameter values.

In one embodiment of the present invention, a moon constraint is proposed, and the following three cases are selectable by the PDPU to determine a moon occlusion constraint: angle 1[ moon, satellite+x axis ] >22 ° (VT), angle 2[ moon, satellite+x axis ] >12 ° (MXT), unconstrained. The SMU judges that the moon is blocked and restricted the following three cases are optional: angle 1[ moon, satellite+x axis ] >20.4 ° (VT), angle 2[ moon, satellite+x axis ] >10.4 ° (MXT), unconstrained. The above parameters support ground instruction modification parameter values.

In one embodiment of the invention, energy constraint is provided, and the depth of discharge of the storage battery is required to be judged before task execution in order to ensure energy safety. Parameter 1: the current storage battery discharge depth is more than 20%; parameter 2: the predicted maximum depth of discharge is >20%; the parameters support ground command modification parameter values, support mask/open functions.

In one embodiment of the present invention, a sailboard rotation strategy is provided, and sailboard rotation time corresponding to different tasks: when GRB/CAT tasks are executed, the sailboard inhibition time is designed, and the sailboard is rotated after the inhibition time; the sailboard inhibition time defaults to 15min, and is adjustable according to the instruction. When GP, toO-NOM and ToO-EX tasks are executed and ToO-MM tasks are executed, after the gesture meets the task requirements (namely, conventional pointing/high-precision pointing is entered), the sailboard is rotated. The sailboard follows the following rotation strategy: condition 1: the predicted rotation angle of the sailboard is less than or equal to 10 degrees (default 10 degrees, and the on-orbit is adjustable), and the sailboard is kept motionless; condition 2: (1) The predicted rotation angle of the sailboard is more than or equal to 30 degrees and is more than 10 degrees (the on-orbit adjustable) (2) the discharge depth of the current storage battery pack is less than 10 percent (the on-orbit adjustable); when the requirements (1) and (2) are met, the sailboard is kept still; condition 3: in other cases, the windsurfing board is turned.

The invention also provides different observation flow designs of each in-orbit observation mode, including the observation flow designs of gamma storm (GRB)/reappearance source (CAT) observation flow, conventional (GP) observation flow and opportunity object (ToO) observation.

Specifically, the gamma storm (GRB)/reproduction source (CAT) observation procedure includes: after the GRB and CAT tasks are positioned by the wide-field load, the satellite autonomously observes the GRB and CAT tasks, except that the source detected by the CAT task is already recorded in the source directory list of the wide-field load. The wide field load and GRM in astronomical observation satellite may find out gamma storm, and the gamma storm is sent to PDPU after being confirmed by the wide field load, and the specific steps are as follows: if the gamma ray monitor GRM detects a gamma storm, a GRM trigger packet is generated and forwarded to a wide-field-of-view load through the PDPU, and the wide-field-of-view load is confirmed to generate a wide-field-of-view load trigger packet; if the gamma storm is detected by the wide field load, the wide field load trigger packet is directly generated. The GRB and CAT task flows are as follows: through a wide-field-of-view load trigger packet, the wide-field-of-view load can collect positioning information (including trigger time T0, gamma storm at ECL field position) of GRB, and the positioning information is forwarded by PDPU and then is downloaded to a ground station by VHF; if the position accuracy of the GRB is better than 13 degrees, the wide-field load maneuvering request mark is set to be effective; and the PDPU calculates the included angles (solar constraint and moon constraint) between the target orientation and the sun and between the target orientation and the moon according to the constraint condition of GRB orientation, and calculates whether the included angles are larger than the judgment condition of the PDPU in the constraint condition of the task mode. If the solar constraint and the moon constraint are all passed, the PDPU converts the target orientation into an attitude quaternion and sends the attitude quaternion to the SMU; the SMU judges according to a task mode constraint condition; after all constraint conditions of the task mode constraint conditions are passed, the satellite starts maneuvering (time T1), the narrow view field load is led to point to the GRB position within 5 minutes, and the current task ID is synchronously broadcast; after the satellite attitude stability reaches the requirement (80'), the GRB is observed and positioned with high precision by the narrow view field load, a high-precision positioning packet is generated, and the positioning packet is forwarded by the PDPU and is transmitted to the ground station by the VHF; the high-precision positioning comprises an optimized pointing direction and quality factor QF value of a current target; when the QF value in the high-precision positioning packet is more than or equal to 2 and the current GRB observation is not more than 2 tracks, the PDPU sends a GRB optimization pointing request at the next conventional mechanical point; the SMU receives the optimization request sent by the PDPU, judges according to the task mode constraint conditions, and starts secondary maneuvering after all constraint conditions of the task mode constraint conditions are passed, and the primary GRB/CAT task only performs primary optimization pointing; the PDPU configures VT working parameters according to the current task ID, information in a high-precision positioning packet and GRB task parameters prestored on the satellite and VT management time sequence to generate VHF and X-band channel data; the GRM generates corresponding VHF and X-band channel data according to the current task ID and the current task mode; the gamma ray monitor and the hard X-ray camera start waiting for the triggering of the next GRB; (T1+15) minutes (adjustable, 15 minutes to 30 minutes), turning the sailboard according to the sailboard turning strategy; after 97 minutes (adjustable) of observation of the current GRB task, the SMU receives a new GRB trigger, and the GRB task within 97 minutes is refused and discarded; without the current GRB mission being interrupted, 14 orbits (adjustable) would be continuously observed, and then the satellite returned to GP or ToO-NOM observations.

In one embodiment of the invention, the conventional (GP) observation procedure comprises: and the GP observation task performs routine observation on scientific targets planned and uploaded in advance by the satellite under the condition that GRB does not occur, and waits for GRB triggering. GP observations include conventional pre-planned observations (GP-PPT) and conventional scaled observations (GP-CAL) tasks. GP-PPT tasks typically observe satellite reference orientations (i.e. "B1 orientations") that lie within ±10° of gamma storm detection optimization. The GP-CAL task is used for load scaling, planned once in about three months. The ground support system plans the direction according to the observation requirement of the GP task, and generates a GP task package after verifying that solar constraint, moon constraint and the like are met, and then the GP task package is injected on the satellite. The on-board GP observation flow is as follows: the ground is injected with a week GP task, which comprises a GP platform task package, a GSP package and a load configuration table; GP tasks are covered in a full period, and 7-98 tasks are carried out weekly; when the task starts, the SMU performs constraint judgment according to a task mode constraint condition; if all constraint conditions are passed, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; turning the sailboard according to the sailboard turning strategy after the satellite is powered on; the PDPU configures VT working parameters according to the current task ID and VT load configuration table; the GRM maintains the current mode.

In one embodiment of the invention, an opportunity object (ToO) observation procedure includes: conventional opportunity object (ToO-NOM) observation flow, important opportunity object (ToO-EX) observation flow, and multi-messenger opportunity object (ToO-MM) observation.

The conventional opportunity object (ToO-NOM) observation procedure includes: the ToO-NOM observation can interrupt GP tasks and can be interrupted by GRB/CAT tasks. ToO-NOM observations include conventional opportunity GRB revisitation targets (ToO-NOM-GRB), conventional opportunity supplemental targeting targets (ToO-NOM-ACAL), and conventional opportunity celestial targets (ToO-NOM-AT) tasks. The on-board ToO-NOM observation procedure is as follows: injecting a one-day ToO-NOM task on the ground, wherein the ToO-NOM task comprises a ToO-NOM platform task package and a load configuration table; 1-5 tasks per day; the SMU performs constraint judgment according to a task mode constraint condition at the task starting time; if all constraints pass, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; the satellite is powered up, and the sailboard is rotated according to the sailboard rotation strategy; the PDPU configures VT working parameters according to the current task ID and VT load configuration table; the GRM maintains the current mode.

Important opportunity target (ToO-EX) observations are the highest priority tasks that can be configured to execute immediately and to execute with delays. The frequency of ToO-EX observations is expected to be 1 per month. The on-board ToO-EX observation procedure is as follows: injecting 1 ToO-EX task on the ground, wherein the ToO-EX task comprises a ToO-EX platform task package and a load configuration table; according to the time parameter in the platform task package, the SMU immediately or according to the set time point, carries out constraint judgment according to the task mode constraint condition; if all constraints pass, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; the satellite is powered up, and the sailboard is rotated according to the sailboard rotation strategy; the PDPU configures VT working parameters according to the task ID and the VT load configuration table; the GRM maintains the current mode. The newly-annotated ToO-EX or ToO-MM task may interrupt the current ToO-EX task.

The observation of a multiple messenger opportunity target (ToO-MM) is a spliced observation, and the task comprises a plurality of tiles, namely a plurality of directions, wherein no more than 5 tiles are in a single track, and the observation time of each tile is about 10 minutes. The maneuver angle of tiles in a track is not more than 10 degrees. The duration of the ToO-MM observation task is not more than 14 tracks, so the number of tiles in one ToO-MM task is not more than 75. The frequency of ToO-MM observations is expected to be 1 per week. The on-board ToO-MM observation procedure is as follows: injecting a ToO-MM task on the ground, wherein the ToO-MM task comprises a ToO-MM platform task package and a load configuration table; the tile starting time is subjected to constraint judgment according to a task mode constraint condition; the current tile constraint is not passed, and the current task is kept; continuously performing constraint judgment according to a task mode constraint condition when the next tile starts; if all constraints pass, the satellite maneuvers to point to the target; synchronously broadcasting the current task ID; the satellite is powered up, and the sailboard is rotated according to the sailboard rotation strategy; the PDPU configures VT working parameters according to the task ID and the VT load configuration table to generate a VHF data packet of the ToO-MM; the GRM maintains the current mode. The steps after the tile start time is shifted continue until all tiles are executed.

The invention also provides an observation task constraint conflict judgment strategy, wherein an astronomical observation satellite is provided with an autonomous planning task, the ground can not predict the current satellite state, and the astronomical observation plans the treatment measures of different observation tasks when the satellite is in a maneuvering process and the energy conditions, sun and moon conditions are not suitable for observation, and the treatment measures are specifically shown in a table 1.

Table 1 constraint not passed task handling Table

Description: strategy 1: aiming at GP, toO-NOM and ToO-EX observation tasks, when the tasks are refused due to unsatisfied energy conditions in maneuver, only the next GSP time point has the opportunity to be executed; strategy 2: for the ToO-MM observation task, when the current tile is rejected, the next tile has an opportunity to be executed. Table 2 gives the handling measures at each task conflict.

TABLE 2 task conflict determination Table

The information of priorities, start times, end times, durations, etc. of the different task modes are given in table 3.

TABLE 3 task management planning

Description: the smaller the priority value, the higher the priority.

Aiming at the complexity and diversity of astronomical observation satellite observation modes, the invention further analyzes the importance of different tasks, combines target characteristics and various constraint conditions, designs a plurality of observation mode management flows such as GP observation, toO observation, GRB observation, CAT and the like, formulates a judgment strategy for task conflict, realizes the collaborative management of ground planning and on-orbit autonomous triggering task interweaving, and has strong flexibility. The astronomical observation satellite observation mode has great reference significance for on-orbit autonomous management.

In summary, the above embodiments describe in detail different configurations of the on-orbit gamma ray storm observation method, and of course, the present invention includes but is not limited to the configurations listed in the above embodiments, and any configuration that is transformed based on the configurations provided in the above embodiments falls within the scope of the present invention. One skilled in the art can recognize that the above embodiments are illustrative.

In the present specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, the description is relatively simple because of corresponding to the method disclosed in the embodiment, and the relevant points refer to the description of the method section.

The above description is only illustrative of the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the appended claims.

Claims

1. An on-orbit gamma ray storm opportunity target observation method for performing opportunity observation on a new discovery source, a known temporary discovery source or a known temporary transformation source is characterized by comprising the following steps:

the observation task planning includes:

2. The on-orbit gamma ray storm target observation method of claim 1 wherein the frequency of the multi-messenger opportunity target observation is expected to be performed 1 time per week;

the observation duration of the observation of the multi-messenger opportunity targets is not more than 14 tracks, and the observation time of each target is 10 minutes;

during normal operation of the astronomical observation satellite, 5 targets were selected within 10 ° x 10 ° in the monorail.

3. The on-orbit gamma ray storm opportunity target observation method of claim 1 wherein said observation mission plan further comprises regular opportunity target observations and important opportunity target observations;

4. The on-orbit gamma ray storm opportunity target observation method of claim 3 wherein a priority of conventional opportunity target observation is lower than a gamma storm observation and reproduction source observation, higher than a priority of conventional observation, and wherein the priority of the important opportunity target observation and the multi-messenger opportunity target observation is higher than a priority of a gamma storm observation and reproduction source observation;

the gamma storm observation includes:

5. An on-orbit gamma ray storm opportunity target observation method as claimed in claim 3 wherein the expected frequency of significant opportunity target observations is 1 time per month.

6. The on-orbit gamma ray exposure opportunity target observation method as set forth in claim 3, wherein the on-orbit gamma ray exposure opportunity target observation direction comprises: the included angle between the sun and the +Xs axis of the astronomical observation satellite is larger than 90 degrees, so that the +X plane of the astronomical observation satellite is not irradiated by the sun;

7. The on-orbit gamma ray storm opportunity target observation method of claim 3 wherein the observation tasks of the conventional opportunity target observation include a conventional opportunity gamma storm revisit target task, a conventional opportunity supplemental calibration target task, and a conventional opportunity celestial body target task;

the high energy load remains in the current mode.

8. The on-orbit gamma ray storm opportunity target observation method of claim 3 wherein the important opportunity target observation comprises immediately executing a task and delaying execution of the task, wherein:

the high energy load remains in the current mode;

9. The method for on-orbit gamma ray storm opportunity target observation according to claim 3, wherein the observation flow of the on-board multi-messenger opportunity target observation is as follows:

the current task is kept if the current constraint is not passed;

the high energy load remains in the current mode;