The astronomical observation satellite and the astronomical telescope carried by the stratospheric balloon are evidently superior to ground observatories. Astronomical observation has demanding requirements for control of the carrier platform: first, extremely high direction accuracy, and even higher attitude stability; second, long duration continuous tracking observation due to weak signals from celestial targets. Thus highly-reliable and safety control will be required. To this end, this paper, taking the Solar Space Telescope (SST) satellite as an example, has first introduced the design method for its high-performance control system, including establishing the equation of motion and defining such input conditions as orbital characteristics, Mass inertia characteristics, whole satellite mode, and performance index requirements. In the aspect of basic design of pointing control system, the configuration of control components has been determined, and the basic structure of attitude determination, control law and filter established. In terms of the detailed design of the performance indices, influence of the component error has been analyzed, controller parameters selected under the premise of ensuring the stability margin. The error distribution has been made to the sensor and the actuator, the sampling period and the computer frequency determined and the angular momentum management strategy established. The simulation results show that the control scheme can meet the stringent control performance requirements. Furthermore, taking the balloon-borne astronomical telescope in the stratosphere as an example, the typical attitude control problems and fault tolerant control requirements have been expounded and the fault tolerant control based on layered and cooperative health monitoring proposed.

High Performance Control and Fault Tolerant Control Requirements of Astronomical Observation Carrier Platform

The Hard X-ray Modulation Telescope (HXMT) is an X-ray astronomical satellite in 1-250 keV, consisting of three collimated instruments We present the in-flight calibration approach of the collimator alignment and Point Spread Function (PSF) for HXMT, using both the direct fitting method and the imaging method According to observational simulations of the Crab Nebula, we find that these two methods produce almost the same calibration accuracy of the alignment, and with a one-day scanning observation, the alignment can be calibrated to better than 045' and 01' along the wide and narrow directions of the Field of View (FOV) for a detector module, which corresponds to a localization accuracy of better than 01' and meets the scientific requirement

Simulation of the in-flight calibration of the collimator alignment and PSF for HXMT

The low energy germanium detector (LEGe) is in all aspects optimised for performance at low and moderate energies. It has specific advantages over conventional planar or coaxial detectors. LEGe is a kind of semiconductor detector commonly used in X-ray detection. It can display the spectrum of X-ray and record photon counts. Photon fluence is used to describe the radiation field by recording the number of incident photons. In order to take full advantage of the low energy response of this intrinsically thin window detector, LEGe cryostats are usually equipped with a beryllium window, thin front and side contact allowing spectroscopy from 3 keV and above. The rear contact is of less than full area which gives a lower detector capacitance compared to a planar device of similar size. It is widely used in low energy gamma spectroscopy, X-ray absorption spectroscopy, nuclear safeguards or X-ray fluorescence spectrometer and X-ray diffraction. Spectrum is an intuitional and accurate description of X-ray radiation. In this work, experiment was carried out to calibrate the detector and test the spectrum, and then to calculate the energy resolution. The experiment results about energy resolution (full width at half maximum) are 222 eV (@5.9 keV) and 519 eV (@122 keV).

Energy calibration and performance testing of LEGe detector

Using the universe as a unique laboratory for probing the laws of physics in regimes not accessible on Earth,such as the very early universe or strong gravity fields near the event horizon of a black hole,is a new common frontier between physics and astronomy.The hard X-ray modulation telescope(HXMT) mission is the first dedicated astronomy satellite in the 2006—2010 five-year plan for space science unveiled by the National Space Administration of China.The HXMT mission will perform a wide band(1—250 keV) all-sky survey with the best sensitivity and angular resolution in the hard X-ray range as a black hole finder and cosmic hard X-ray background observer,and make sensitive pointed timing and spectral observations for studying the underlying physics processes of black holes and other compact objects.Fifteen years have passed since the submission of the HXMT proposal based on a new imaging technique.It is still a challenge for China to see if the scientific opportunity created by such a technological innovation can be finally grasped.

The hard X-ray modulation telescope mission

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Li Ti

Author Tools

Chat about Author

Papers

The hard X-ray modulation telescope mission