... The gyro rate data minimizes the effects of noise from the star measurements, and the long-term accuracy of the star data provides a high-fidelity estimate of the gyro bias drift. ... The filter estimates 3-axis error in current attitude estimate and 3-axis gyroscope drift rate, resulting in six estimated quantities referred to as the filter "state." ... In the upper left graph, the solid line shows the actual pitch estimate error for a 500 second nominal dither observation. ...

Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders . ... Archives . ... A postdoc job announcement from Prof. Joshua Bloom of UC Berkeley: . ... The starting salary will be commensurate with experience, and competitive with other postdoctoral positions. ... Tags: AstroStat , computer science , job announcement , job market , time series , UC Berkeley . ... Joseph Hilbe on [Jobs] postdoc position at UC Berkeley . ... Chandra Blog . ...

The Chi-Square Goodness of Fit Statistic . This statistic enables us to test whether observed frequencies are close to . those we would expect. ... Expected frequencies . ... For example, if we . have an honest die we would expect 1/6 of all cases to show any of . ... So, for example, if we roll a die 60 times we would expect : . ... If we actually roll a die 60 times we wouldn't expect each of the faces . ... times each face actually comes up is the observed frequency for that face. ...

... Analysis of in-orbit data closely follow the CSL data analysis. Stars with known astrometric positions are matched with their image centroids. ... The measured position, the expected position and the offset between the measured and expected positions are calculated and written into a file. ... select catalogued positions for different observations/pointings (e.g. positions of objects in photometric sequence) . ... The new distortion map was generated from in-flight observations of the G153 field. ...

... Moons, Rings, and Unexpected Colors on Saturn . ... Credit: Cassini Imaging Team , SSI , JPL , ESA , NASA Explanation: Why would Saturn show such strange colors? The robotic Cassini spacecraft currently orbiting Saturn has beamed back images showing that the northern hemisphere our Solar System 's most spectacularly ringed planet has changed noticeably since Cassini arrived in 2004, now sporting unusual and unexpected colors. ... Publications with keywords: Saturn - cassini spacecraft . ...

link to plots: system performance before and after the horn move. ... Focus curves done on each receiver showed that all of the kildal horns had a platform focus position about .5 lambda below the non-kildal horns (and below the expected position). ... Fig 1 top is the gain [K/Jy] before (black) and after (red) the move. ... Fig 2 shows the gain,Tsys,Sefd, and average beam widths before (black) and after (red). ... Fig 4 plots the pointing error before (black) and after (red). ...

... HST . STIS-08 . ... Data . ... HST Overview . ... This activity has five functions: verification of the aperture positions, verification of absolute optical position, verification of slit wheel repeatability, verification of lamp functionality, and verification of CCD imaging mode functionality. Verification of the aperture positions: Determine the location of the slit positions, in pixel coordinates, on the STIS CCD detector for a representative subset of STIS acquisition apertures and slits. ...

... 2008 October 20 . Moons, Rings, and Unexpected Colors on Saturn . Credit: Cassini Imaging Team , SSI , JPL , ESA , NASA . Explanation: Why would Saturn show such strange colors? The robotic Cassini spacecraft currently orbiting Saturn has beamed back images showing that the northern hemisphere our Solar System 's most spectacularly ringed planet has changed noticeably since Cassini arrived in 2004, now sporting unusual and unexpected colors. ... About APOD | ...

... These are ``quirks'' rather than ``bugs''. Below is a list of quirks. When loading a file and ``Reset Intensity Upon File Load'' is disabled, the intensity range of the previous image will be used. ... When moving between two images (such as when blinking, or when loading a new image), the display system attempts to retain the old image parameters (i.e. zoom box). What is retained are the corners of the zoom box measured in image pixel co-ordinates, not world co-ordinates. ...

The overall efficiency (including atmospheric transmission, reflectivity of the telescope mirrors and overall efficiency of the optics and of the detector) for broad-band imaging should be about 25% in H and K, and about 15% in J. The main noise source for both broad- and narrow-band imaging should be the photon noise associated to the background+source flux. ... Flat fielding (and possibly background subtraction) might increase the noise by a factor 2 ? ...

Next: Catalog Construction Up: Observations and Analysis Previous: Source Detections . ... It was assumed that the highest signal gives the most likely position of the source. ... Comparing the summed map with the maps from the individual energy ranges, the one which produced the smallest error box was chosen to represent the source position, as long as was greater than 4, a level chosen to reflect a reasonable degree of confidence in the detection. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... A fixed-term Research Technicia