Line of sight jitter of the hubble space telescope bely, pierre y. The influence of model uncertainty with model tuning based on. An example of correlated aperiodic jitter is interference on a. Jitter test program and onorbit mitigation strategies for. 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. The jitter and total delay are not even close to be the same thing. We report on the results of a dedicated onorbit test which we have performed to measure the lineofsight jitter of the hubble space telescope.
Correlated jitter on a clock is deterministic and always caused by and correlated to a noise source. Lineofsight jitter of the hubble space telescope deepdyve. Jitter transfer sonetsdhjitter transfer sonetsdh clock recovery performance as a function of jitter frequency. Structural lineofsight jitter analysis for mlcd spie digital library. 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. Effect of jitter on an imaging ftir spectrometer unt. Reaction wheel disturbance modeling, jitter analysis, and. 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.
The line of sight stabilization and tracking control based on gyro stabilized platform is required to. The test, which made use of one of the science instruments on board the spacecraft, had a very high. Figure 1 sdo jitter test plan and disturbancetoperformance flow ii. Jitter results from network congestion, timing drift and route changes. Structural lineofsight jitter analysis for mlcd structural lineofsight jitter analysis for mlcd doyle, keith b. 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. This reduces system complexity and cost by eliminating the need to mitigate vibration at every source. Jitter overview the jitter working group of the fibre channel industry association1, after countless cups of highoctane coffee, produced a groundbreaking report. It will usually mean that, because there is more jitter, you need more jitter buffer, to be able to compensate. Acquisition, tracking, pointing, and line of sight control laboratory experiments for a spacebased bifocal relay mirror.
Oct 25, 2016 the jitter and total delay are not even close to be the same thing. Integrated analysis, fea, optomechanics, lineofsight jitter, mtf, random. 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. Lineofsight jitter of the hubble space telescope lineofsight jitter of the hubble space telescope bely, pierre y.
Robust lineofsight stability and jitter compensation using spatiotemporalfiltering based control approaches stuart j. Sightline jitter minimization and shaping using nonlinear friction compensation article pdf available in international journal of optomechatronics. Aaol for prediction of optical jitter due to flight disturbances. Apply sinusoidal jitter of specified amplitude and frequency. Lineofsight jitter of the hubble space telescope nasaads. 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. Image jitter detection and compensation using a high. Line of sight jitter of selex optical terminals, analysis and verification activities ph. Design and optimal control of line of sight stabilization. Lineofsight jitter analyses were performed on the mars. This accurate line quality test can alert you to any potential problems on your adsl line. Line of sight jitter analyses were performed on the mars terminal payload that accounted for the passive and active stabilization systems, the elastic response of the payload, and the detailed elastic characteristics of the isolator. Pdf sightline jitter minimization and shaping using nonlinear.
Jbert combines all these jitter types to create such a compliance eye needed for receiver jitter tolerance testing. As was previously known from gyroscope data analysis, the bulk. Integrated lineofsight modeling of the airborne aero. Conference proceedings of the society for experimental mechanics series. Jun 23, 2016 what is acceptable jitter jitter is the irregular time delay in the sending of data packets over a network. High frequency design jitter fundamentals from april. 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. Having a lot of jitter in the network will probably increase the total delay to, but this should be avoided. 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. To diagnose the rv jitter, several complementary approaches are commonly used, mostly making use of chromospheric activity indicators like excess.
Subject terms laser, directed energy, lineofsight, beam control, jitter. Using high speed scope for digital jitter measurements. Lineofsight jitter of selex optical terminals, analysis and verification activities ph. The period of each cycle of the oscillator is different, due to the noiseinduced jitter.
Pdf sightline jitter minimization and shaping using. Random jitter is assumed to follow a gaussian distribution and is defined by the mean and sigma of that gaussian distribution. Structural lineofsight jitter analysis for mlcd 2007. Robust lineofsight stability and jitter compensation using. Sightline jitter minimization and shaping using nonlinear friction. Request pdf adaptive jitter control for tracker line of sight stabilization a field test experiment on a range tracking telescope at the u. 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. Acceptable jitter means what we are willing to accept as the irregular fluctuations in. The performance of laser optic systems depends on how well jitter can be reduced or eliminated. Lineofsight jitter analyses were performed on the mars terminal payload that accounted for the passive and active. The sda measures the jitter pdf by collecting a histogram of tie measurements. E student1, assistant professor2, professor and head3 department of electrical engineering, nitttr, chandigarh abstract. Both additive noise and jitter on the line of sight contribute to errors in the reconstruction of the pattern from dither scan samples.
An example of correlated aperiodic jitter is interference on a clock from a serial line. 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. So if we measure sigma is 10 picoseconds, then we would say the random jitter is 141 psec. 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. Jitter period is the interval between two times of maximum effect or minimum effect of a signal characteristic that varies regularly with time. Reducing spacecraft jitter during satellite reorientation. We could use any berr but 1012 is quite common to use and 1012 equals to 14. The line test above works by sending packets from our server straight to your computer and reporting as it is doing so. Dynapak 16 triaxial sensor packages provide a wide bandwidth angular rate. Your line of sight is an imaginary line that stretches between your eye and the object. 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 effect of jitter on an imaging ftir spectrometer. This formulation is not valid for many space systems, but is important in stellar interferometers, large monolithic space telescopes, and. Ease of use let engineers focus on analyzing their designs rather than learning how to use test equipment.
Integrated lineofsight modeling of the airborne aerooptics. An integrated lineofsight model that predicts closedloop jitter of the aaol system is presented. A stabilized optical lineofsight system incorporating an ata oiru is designed to reject broadband jitter. Directed energy beam jitter mitigation using the lineofsight. Robust lineofsight stability and jitter compensation using spatio temporalfiltering based control approaches. Electrooptical eo imaging sensors mounted on a mobile platform usually require some form of control to stabilize the sensor. Extrapolating the pdf measuring the total jitter requires that the probability density function of the jitter is known exactly. Llcd experimental lineofsight jitter testing springerlink. Acquisition, tracking, pointing, and lineofsight control laboratory experiments for a spacebased bifocal relay mirror.
Previous studies have shown that the addition of jittering motion into a visual inducer facilitates vection. 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. The lineofsight jitter induced by the onboard disturbance sources is a major contributor to th e overall pointing performance. Modeling the rv jitter of early m dwarfs using tomographic. An example of correlated jitter is periodic jitter, as in the case of a system power supply. A survey of reaction wheel disturbance modeling approaches for spacecraft lineofsight jitter performance analysis cornelius j. Structural lineofsight jitter analysis for mlcd deepdyve. Historically, reaction wheels rws have been the principal sources of spacecraft onboard disturbances on nasa and esa missions. Jitter noun the short term phase variation of the significant instants of a digital signal from their ideal positions in time. Sep, 2007 structural line of sight jitter analysis for mlcd structural line of sight jitter analysis for mlcd doyle, keith b.
The allowable jitter is a function of the sensor resolution and beam width of the. Pdf robust lineofsight stability and jitter compensation. Robust line of sight stability and jitter compensation using spatiotemporalfiltering based control approaches stuart j. 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. Line of sight definition and meaning collins english. This assumes that the gaussian rj pdf appends to the dj pdf. A study of reaction wheel disturbance modeling approaches for.
Robust lineofsight stability and jitter compensation. A study of reaction wheel disturbance modeling approaches. Satellite platform jitter is an important factor restricting the imaging quality of highresolution hr optical satellite images. Jitter is a statistical measure of a noisy oscillation process. The lineofsight is the vector drawn between an imaging sensor and target. Rotational jitter around the observers line of sight can. Design and optimal control of line of sight stabilization of. Common obstacles between radio transmitters and radio receivers are tall buildings, trees, physical landscape and highvoltage power. Acquisition, tracking, pointing, and lineofsight control.
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. 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. Adaptive jitter control for tracker line of sight stabilization. A heuristic discussion of fibre channel and gigabit ethernet methods 1. 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. Confidence in measurement results repeatability from one test system to the next. Lineofsight jitter of the hubble space telescope 1993. Design and optimal control of line of sight stabilization of moving target ajeet singh1, ritula thakur2, dr. Bennett lawrence livermore national laboratory, l45, livermore, ca. Mechanisms mounted on the observatorys spacecraft bus are typically the source of jitterproducing disturbances.
Broadband line quality test check your internet connection. After implementing the optical jitter blur in a baseline high resolution image, the simulation considerably reduced the frames spatial resolution and intensity. 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.
Disturbance inputs include measured inflight base loading and measured pressure. Home proceedings volume 6665 article translator disclaimer. Frictioninduced sightline jitter significantly degrades the image resolution and detection range of a stabilised optical system. Understanding jitter, its components, and separation. 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.
An integrated line of sight model that predicts closedloop jitter of the aaol system is presented. Line of sight jitter analyses were performed on the mars terminal payload that accounted for the passive and active stabilization systems. The effect of jitter on an imaging ftir spectrometer charles l. For obstacles that intrude into the first fresnel zone but do. 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. 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. Jitter is especially problematic in realtime communications like ip telephony and video conferencing.
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