... The system is based on two straight lines ("axes"), perpendicular to each other, each of them marked with the distances from the point where they meet ("origin")--distances to the right of the origin and above it, the origin being taken as positive and on the other sides as negative (see drawing below). ... One system (" polar coordinates ") uses the length r of the line OP from the origin to P (i. e. the distance of P distance to the origin) and the angle that line makes with the x-axis. ...

Program: TRACE Purpose: TRACE plots image values at user given positions as function of distance to a plot centre (in 2-d (sub)sets). Category: ANALYSIS, PLOTTING File: trace.c Author: M.G.R. Vogelaar Keywords: INSET= Give set (, subset): Only one subset is allowed. ... XYBOX= Give size of box around one pixel: [3,3] The resulting value at a selected position is an average of the pixels in the defined box around that position. ... POSITION= Give position x, y: Physical values are allowed. ...

... The exact directions of the offsets are parallel to the rows and columns of the CCD on which the aperture is specified. ... It is often useful to explicitly specify the desired rotation of the WFPC2 field-of-view on the sky. ... Figure 7.8 shows the CCD orientation and aperture locations relative to the U3 axis. ... Obtain the Position Angle (PA) of the source axis on the sky, measured in the standard way, North through East. ... desired source angle in field-of-view measured CW from +U3 axis) . ...

... An OBJECT column gives the name of the object observed (usually a star name). ... In critical cases, it is common practice to measure sky on two or more positions around a target object, and these positions must be identified. ... A general treatment of this problem requires a column called OBJECT, bearing the usual name of the object (as in the star tables); a column labelled STARSKY, to distinguish between star+sky, star alone, or sky alone; and additional columns to identify the sky position. ...

The pitch, roll, and focus errors measured in aug01 can be corrected by rotating the dome by .12 degrees in roll and shimming a linear ramp in pitch of .125 degrees between za=10 and za=20 degrees ( see the simulation ). ... Let y2, y1 be the vertical positions of the two ends of this beam (y2 is the uphill coordinate). ... In reality, y2 is 1.464 degrees uphill from the center of the beam while the za optic axis is 1.1113 degrees uphill from the center of the beam suport. ...

Next: Generation from In-Orbit Data Up: ASTROMET Previous: Description Contents . ... The pinhole positions were scaled, rotated and shifted until the best match between pinhole position and measured image was achieved. A pinhole starmask image in the correct position was generated (starmask_new.fits). ... 382.431 cm Pinholes starmask positions and centroids of the measured images were paired, and the difference between measured and expected positions is written to a file (routine DISTORT.PRO). ...

The rotation type specifies the meaning of the rotation angle. Only Object and Horizon are typically used for science (or None if your instrument does not have a rotator). ... Mount is typically used for engineering. ... Mount: rotator angle used by the rotator axis controller. ... For an instrument with a rotator: if you specify a rotation type of None and the rotator is moving then it will be halted at approximately its current position; this feature use used to implement a controlled stop. ...

... One way (" polar coordinates ") uses the length r of the line OP from the origin to P (i. e. the distance of P distance to the origin) and the angle that line makes with the x-axis. ... Look again at the surveyor's telescope: the direction to which it points is completely specified by two angles--its azimuth f , the angle by which its base is rotated on a horizontal table-- and its elevation l (small Greek L), the angle by which it is lifted above the horizontal (if it looks down, l is negative). ...

Next: *wcscoord* all Up: Celestial Coordinates from Image Previous: *tvlabel, xexamine* . ... Type pixel coords in skypix . xr xspatial xs skypix .oformat = ``hours'' # to reset the default which is ``degrees''. xs skypix input coordinate system ( J2000 ): xdata$rh110267_img # the image file name output coordinate system ( J2000 ): image # to use coord conversion # in image file header or B1950 or J2000 # epoch of output can be specified input file list (STDIN): cr ...

ON THE IMPACT OF THE GALACTIC ABERRATION ON VLBI-DERIVED PRECESSION MODEL Z.M. MALKIN Pulkovo Observatory Pulkovskoe Ch. ... Corrections to adopted precession rate are usually computed from the linear trends in long-term time series of celestial pole offset (CPO), which are the differences between the measured and the theoretical coordinates of the celestial pole. ... CONCLUSIONS We have estimated the impact of GA on parameters of precession-nutation model derived from VLBI observations. ...

I/146 Positions and Proper Motions (Roeser+ 1988) ================================================================================ Catalogue of Positions and Proper Motions Roeser S., Bastian U. =1988A .. ... 449R ================================================================================ ADC_Keywords: Positional data; Proper motions Description: PPM North gives J2000 positions and proper motions of 181,731 stars north of -2.5 degrees declination. ... The mean epoch is near 1931. ...

polimodel -- Produce model linear polarization and position angle images . ... Whether to apply random errors to output polarization and position angle values. seed = "" [integer] . ... This task produces a model linear polarization image and corresponding position angle image from an input image assumed to represent intensity (Stokes I parameter). ... A threshold for the input image can be defined such that polarization and position angle are not computed for input values less than this threshold. ...

polimodel -- Produce model linear polarization and position angle images . ... Whether to apply random errors to output polarization and position angle values. seed = "" [integer] . ... This task produces a model linear polarization image and corresponding position angle image from an input image assumed to represent intensity (Stokes I parameter). ... A threshold for the input image can be defined such that polarization and position angle are not computed for input values less than this threshold. ...

... Activity 3: Measuring the Position of the Sun in the Sky . Purpose: To give students the opportunity to measure the position of the Sun in the sky using simple tools and methods. ... Alternatively, you may have students devise their own methods of relative measurement and apply them to measuring the position of the Sun in the sky. ... Rangi is the sky, and when the Sun is near Rangi's head it is summer in New Zealand. ... Read the Maori story to students. ... back to Teachers' Newsletter Main Page ...

... Positions in 2000 - Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec . Positions in 2001 - Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec . Positions in 2002 - Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec . Positions in 2003 - Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec . Positions in 2004 - Jan - Feb - Mar - Apr - May - Jun - Jul - Aug - Sep - Oct - Nov - Dec . ...

. Next: Initial velocity Up: Space and velocity distributions Previous: Space and velocity distributions . Following Paczynsky (1990), we assume initial space distribution of young neutron stars to be varying exponentially with distance from the Galactic center and from the Galactic plane, that is probability distribution for young neutron star positions can be written in the form . with kpc, and pc. Mike E. Prokhorov . Fri Jul 19 19:16:07 MSD 1996

Stellarium 0.12.3 . ... Classes . ... gSatTEME Class Reference . Sat position and velocity predictions over TEME reference system. ... Set compute epoch for prediction. ... gVector љ . ... Get the TEME satellite position Vector. ... Get the Geographic satellite subpoint Vector calculated by the method compute SubPoint. ... gVector Satellite position vector meassured in Km. x: position[0] y: position[1] z: position[2] . ... gVector Satellite Velocity Vector measured in Km/s x: Vel[0] . ...

... The HST uses an onboard model of its orbit to perform in real-time various control functions relating to spacecraft operations and observation support. ... New coefficients for the ephemeris are updated every other day, and are archived as FITS keywords for each HST observation data set. Using these coefficients,an observer can perform a variety of calibration and characterization calculations relating to the orbital position and velocity of the telescope. ...

... Q 12.649 0.523 0.342 -0.108 4444 -4.647 -4.582 "n6231_ 178" 16 53 48.63 -41 51 54.1 J2000.0 ! ... A few lines are then added to the top (see readme_asc2dxf for details) to produce input for asc2dxf :in.coo: n6231cp6.dxf slot line 2.00 43.00 9.00 43.00 point 9.773 19.026 n6231 _ 171 Q 12.649 11.236 57.382 n6231 _ 178 I 14.533 ... the output of this program is as follows :n6231cp6.dxf: 0 SECTION 2 ENTITIES 0 CIRCLE 8 1 62 3 10 43.00 20 43.00 30 0.000 40 43.00 0 ...