Design and optimal control of line of sight stabilization of moving target ajeet singh1, ritula thakur2, dr. Integrated lineofsight modeling of the airborne aero. Lineofsight jitter analyses were performed on the mars. Jitter test program and onorbit mitigation strategies for. Lineofsight jitter of the hubble space telescope nasaads. The performance of laser optic systems depends on how well jitter can be reduced or eliminated.
Extrapolating the pdf measuring the total jitter requires that the probability density function of the jitter is known exactly. Jitter performance is given in terms ofthe strehl ratio ofthe optics system in the farfield. To diagnose the rv jitter, several complementary approaches are commonly used, mostly making use of chromospheric activity indicators like excess. Structural lineofsight jitter analysis for mlcd spie digital library. Jun 23, 2016 what is acceptable jitter jitter is the irregular time delay in the sending of data packets over a network. Jitter noun the short term phase variation of the significant instants of a digital signal from their ideal positions in time. Image jitter detection and compensation using a high. Reducing spacecraft jitter during satellite reorientation. The effect of jitter on an imaging ftir spectrometer. To address the critical issue of compensation for attitude jitter in hr images, this paper proposes a steadystate reimaging model using highfrequency angular displacement data to detect and compensate for the attitude jitter of hr images. Adaptive jitter control for tracker line of sight stabilization.
A heuristic discussion of fibre channel and gigabit ethernet methods 1. A study of reaction wheel disturbance modeling approaches for. Using high speed scope for digital jitter measurements. The lineofsight is the vector drawn between an imaging sensor and target. Structural lineofsight jitter analysis for mlcd structural lineofsight jitter analysis for mlcd doyle, keith b. This accurate line quality test can alert you to any potential problems on your adsl line.
Structural lineofsight jitter analysis for mlcd deepdyve. Design and optimal control of line of sight stabilization of. Acquisition, tracking, pointing, and line of sight control laboratory experiments for a spacebased bifocal relay mirror. Robust line of sight stability and jitter compensation using spatiotemporalfiltering based control approaches stuart j. Common obstacles between radio transmitters and radio receivers are tall buildings, trees, physical landscape and highvoltage power. Dynapak 16 triaxial sensor packages provide a wide bandwidth angular rate. We report on the results of a dedicated onorbit test which we have performed to measure the lineofsight jitter of the hubble space telescope.
Jitter transfer sonetsdhjitter transfer sonetsdh clock recovery performance as a function of jitter frequency. Lineofsight jitter of the hubble space telescope 1993. Line of sight jitter of selex optical terminals, analysis and verification activities ph. Jitter results from network congestion, timing drift and route changes. Since the process requires multiple samples to effect cancellation, the performance of the process is dependent on the stability of the line of sight over the collection interval. An integrated line of sight model that predicts closedloop jitter of the aaol system is presented. Abstract a central aspect in the design of the mars lasercom terminal was limiting the line of sight jitter of the optical payload due to translational and angular dynamic excitation from the host spacecraft. Sightline jitter minimization and shaping using nonlinear friction. The line test above works by sending packets from our server straight to your computer and reporting as it is doing so.
Figure 1 sdo jitter test plan and disturbancetoperformance flow ii. Line of sight jitter analyses were performed on the mars terminal payload that accounted for the passive and active stabilization systems. Jitter overview the jitter working group of the fibre channel industry association1, after countless cups of highoctane coffee, produced a groundbreaking report. Apply sinusoidal jitter of specified amplitude and frequency. The test, which made use of one of the science instruments on board the spacecraft, had a very high sensitivity a fraction of a milliarcsecond and covered all frequencies up to 500 hz. Design and optimal control of line of sight stabilization. This allows our test to see if there is any packet loss, what the average network latency of your line is and provides a jitter measure. Rotational jitter around the observers line of sight can.
Aaol for prediction of optical jitter due to flight disturbances. For obstacles that intrude into the first fresnel zone but do. Random jitter is assumed to follow a gaussian distribution and is defined by the mean and sigma of that gaussian distribution. Conference proceedings of the society for experimental mechanics series. Jitter in ip networks is the variation in the latency on a packet flow between two systems, when some packets take longer to travel from one system to the other.
Dynapak 16 3axis ars16 sensor packages the dynapak 16 is designed to measure angular jitter from terrestrial, airborne, and spacecraft mirrors, optical systems or lasers, and for accurate line of sight imaging and platform stabilization. Request pdf adaptive jitter control for tracker line of sight stabilization a field test experiment on a range tracking telescope at the u. Robust lineofsight stability and jitter compensation. Confidence in measurement results repeatability from one test system to the next. Desplats matra marconi space, 31 rue des cosmonautes, 31077 toulouse cedex, france abstract the semiconductor laser intersatellite link experiment silex is a very innovative program of the european. Acquisition, tracking, pointing, and lineofsight control laboratory experiments for a spacebased bifocal relay mirror. An integrated lineofsight model that predicts closedloop jitter of the aaol system is presented. An example of correlated jitter is periodic jitter, as in the case of a system power supply. Mechanisms mounted on the observatorys spacecraft bus are typically the source of jitterproducing disturbances.
After implementing the optical jitter blur in a baseline high resolution image, the simulation considerably reduced the frames spatial resolution and intensity. Effect of jitter on an imaging ftir spectrometer unt. Nonline of sight nlos refers to the path of propagation of a radio frequency rf that is obscured partially or completely by obstacles, thus making it difficult for the radio signal to pass through. A survey of reaction wheel disturbance modeling approaches for spacecraft line of sight jitter performance analysis cornelius j. Disturbance inputs include measured inflight base loading and measured pressure. It will usually mean that, because there is more jitter, you need more jitter buffer, to be able to compensate. The period of each cycle of the oscillator is different, due to the noiseinduced jitter. Structural lineofsight jitter analysis for mlcd 2007. Llcd experimental lineofsight jitter testing springerlink. We report on the results of a dedicated onorbit test which we have performed to measure the line of sight jitter of the hubble space telescope. This histogram approximates the pdf by counting the number of edges occurring within the time period delimited by each bin in the histogram.
The automated jitter tolerance compliance just measures the compliance curve again. Jul 09, 2015 jitter in ip networks is the variation in the latency on a packet flow between two systems, when some packets take longer to travel from one system to the other. Previous studies have shown that the addition of jittering motion into a visual inducer facilitates vection. Satellite platform jitter is an important factor restricting the imaging quality of highresolution hr optical satellite images. We could use any berr but 1012 is quite common to use and 1012 equals to 14. Acquisition, tracking, pointing, and lineofsight control.
Home proceedings volume 6665 article translator disclaimer. High frequency design jitter fundamentals from april. Having a lot of jitter in the network will probably increase the total delay to, but this should be avoided. Ease of use let engineers focus on analyzing their designs rather than learning how to use test equipment. Jitter is a statistical measure of a noisy oscillation process. A central aspect in the design of the mars lasercom terminal was limiting the lineofsight jitter of the optical payload due to translational and angular dynamic excitation from the host spacecraft. Acceptable jitter means what we are willing to accept as the irregular fluctuations in. Robust lineofsight stability and jitter compensation using spatiotemporalfiltering based control approaches stuart j. Directed energy beam jitter mitigation using the lineofsight. Pdf sightline jitter minimization and shaping using nonlinear. Frictioninduced sightline jitter significantly degrades the image resolution and detection range of a stabilised optical system. Jitter frequency, the more commonly quoted figure, is its inverse.
Understanding jitter, its components, and separation. An observer will thus be in a particles radiative cone over some length of its accelerated path, until the particle direction is suf. The allowable jitter is a function of the sensor resolution and beam width of the. Lineofsight jitter of the hubble space telescope lineofsight jitter of the hubble space telescope bely, pierre y. As was previously known from gyroscope data analysis, the bulk. Your line of sight is an imaginary line that stretches between your eye and the object. Robust lineofsight stability and jitter compensation using. Correlated jitter on a clock is deterministic and always caused by and correlated to a noise source.
Electrooptical eo imaging sensors mounted on a mobile platform usually require some form of control to stabilize the sensor. Jitter period is the interval between two times of maximum effect or minimum effect of a signal characteristic that varies regularly with time. In order to suppress the lf noise component which occurs due to accumulated noise errors during reconstruction, a complementary filter is employed which provides low spatial frequency data from the original. The sda measures the jitter pdf by collecting a histogram of tie measurements. Sightline jitter minimization and shaping using nonlinear friction compensation article pdf available in international journal of optomechatronics. Lineofsight jitter analyses were performed on the mars terminal payload that accounted for the passive and active. The airborne aerooptics laboratory aaol was designed to measure the effects of turbulent flow on the wavefront of a laser projected from an airplane in flight. The line of sight stabilization and tracking control based on gyro stabilized platform is required to. Historically, reaction wheels rws have been the principal sources of spacecraft onboard disturbances on nasa and esa missions. Both additive noise and jitter on the line of sight contribute to errors in the reconstruction of the pattern from dither scan samples.
The jitter and total delay are not even close to be the same thing. Robust lineofsight stability and jitter compensation using spatio temporalfiltering based control approaches. This reduces system complexity and cost by eliminating the need to mitigate vibration at every source. We characterize the radio frequency dependence of jitter using data on 48 pulsars in the north american nanohertz observatory for gravitational waves timing program. The test, which made use of one of the science instruments on board the spacecraft, had a very high. Pdf sightline jitter minimization and shaping using. A psychophysical experiment with 12 observers found that the expanding visual inducer, which contained rotational jitter around the observers line of sight, can induce stronger forward vection than a pure radial expansion without any additional jittering component. So if we measure sigma is 10 picoseconds, then we would say the random jitter is 141 psec. Modeling the rv jitter of early m dwarfs using tomographic.
A survey of reaction wheel disturbance modeling approaches for spacecraft lineofsight jitter performance analysis cornelius j. Lineofsight jitter of selex optical terminals, analysis and verification activities ph. Integrated lineofsight modeling of the airborne aerooptics. This formulation is not valid for many space systems, but is important in stellar interferometers, large monolithic space telescopes, and. The influence of model uncertainty with model tuning based on. Subject terms laser, directed energy, lineofsight, beam control, jitter. Pdf robust lineofsight stability and jitter compensation.
This assumes that the gaussian rj pdf appends to the dj pdf. Oct 25, 2016 the jitter and total delay are not even close to be the same thing. Reaction wheel disturbance modeling, jitter analysis, and. To accomplish this, an integrated lineofsight model was derived from a finite element model of the system, optical sensitivities and control loops for calculation of closed loop, lineofsight jitter. Integrated analysis, fea, optomechanics, lineofsight jitter, mtf, random. Bennett lawrence livermore national laboratory, l45, livermore, ca. Broadband line quality test check your internet connection. Jitter is especially problematic in realtime communications like ip telephony and video conferencing. Lineofsight jitter of the hubble space telescope deepdyve. If you just want to add jitter to the lines in the plot, the following code will do it. Random jitter is unbounded, if we wait long enough we would have hits anywhere in the eyediagram. Sep, 2007 structural line of sight jitter analysis for mlcd structural line of sight jitter analysis for mlcd doyle, keith b.
Line of sight jitter of the hubble space telescope bely, pierre y. Jbert combines all these jitter types to create such a compliance eye needed for receiver jitter tolerance testing. E student1, assistant professor2, professor and head3 department of electrical engineering, nitttr, chandigarh abstract. The mission requirements are for a 3m spot beam on the ground, jitter less than 144 nanoradians, and 250 seconds mean dwell duration per pass. Strehl ratio is defined as the ratio ofthe peak intensity of the transmitted beam in the farfield divided by the peak intensity of an ideal transmitted beam. An example of correlated aperiodic jitter is interference on a clock from a serial line. Dynapak 16 3axis ars16 sensor packages the dynapak 16 is designed to measure angular jitter from terrestrial, airborne, and spacecraft mirrors, optical systems or lasers, and for accurate lineofsight imaging and platform stabilization. Line of sight definition and meaning collins english. An example of correlated aperiodic jitter is interference on a. Both additive noise and jitter on the line of sight contribute to errors in the reconstruction of. The effect of jitter on an imaging ftir spectrometer charles l. A study of reaction wheel disturbance modeling approaches.
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