... sin f = y / r . cos f = x / r . ... They are now viewed as new definitions of the sine and cosine, for the polar angle f given by x and y ( a slightly different way of formulating this definition is described further below ). ... sin 2 f + cos 2 f = 1 . ... Angle . ... Many trigonometry texts define the sine and cosine slightly differently, using the so-called unit circle . ... Then the distance AB ("the sine line") equals sin a , and the distance OA ("the cosine line") equals cos a . ...

... In polar coordinates, the point P is defined by its distance r from the origin O (see drawing) and by its polar angle ("azimuth" on a map) between the x-axis and the "radius" r = OA, measured counter-clockwise. ... When one or both are negative , the angle f is larger than 90 degrees, and such angles never appears in any right-angled triangle. ... There is a simple solution , though: use the above equations to re-define sin f and cos f for such larger angles! ... But it also works for larger angles....

... 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) . ...

lsst.coordConv љ unknown . ... coordConv::Coord Class Reference . ... Coord (double equatAng, double polarAng, double parallax=0) . ... Definition at line 27 of file coord.h . ... Definition at line 227 of file coord.cc . ... Definition at line 150 of file coord.cc . ... Definition at line 134 of file coord.cc . ... Definition at line 142 of file coord.h . ... Definition at line 135 of file coord.h . ... Definition at line 141 of file coord.cc . ... Definition at line 172 of file coord.cc . ...

... The first of the equations defines the position of the spectral orders, m , in the raw image, while the second equation gives, for each order, the dispersion relation in one dimension. ... where the coefficients are computed using least squares techniques on a grid , i.e. sample number and line number of points located within the spectral orders of the image. These points in the grid are found automatically by an order--following algorithm, normally using the FLAT or STD image. ...

... Classes . ... Class List . ... casa . casa::SolarPos . ... Solar position class and calculations. ... SolarPos (const SolarPos &other) . ... operator() ( Double epoch) . ... Barycentric position of Earth. const MVPosition & casa::SolarPos::baryEarthDerivative . ... Barycentric position of Sun. const MVPosition & casa::SolarPos::barySunDerivative . ... Double casa::SolarPos::checkEpoch [private] . ... Double casa::SolarPos::checkSunEpoch [private] . ... Double casa::SolarPos::deval [3] [private] . ...

... The routine returns the offset (deltaX, deltaY) from the linear grid position for a specified detector location. ... the distortion (deltaX, deltaY) at the detector location (rawX, rawY) is derived from the distortion map stored in the extension FILTER-FilterId (e.g. FILTER-U, FILTER-V, FILTER-GRISM1 etc.) ... interpolate the extracted distortion points (RAWX_OFF ,RAWY_OFF ) and calculate the distortion (deltaX,deltaY) at the requested postion (rawX, rawY) . ... deltaX, deltaY . ...

... 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. ...

... When feed is rotated over the tertiary: . ... z is toward the tertiary from the focus position . ... angle : Center of rotation is about the optical axis. range 0 to 360 degrees (minus a few degrees for the limits) . ... CW when sitting on the tertiary looking up at the dipoles. radius : moves in the x,y plane along the direction that the angle currently points . ... Dipole positions : . ... D1 is at the center of the dipole array. processing: x101/projects/byuPhAr/idl/doplotoff.pro . ...

... Description . Catalog . ... In the Catalog, we publish equatorial (ЮБ 2000 , ЮД 2000 ) and galactic (l,b) coordinates of cluster centers derived as the position of overdensity in 2MASS catalog (Koposov et al. ... Distances, color-excesses and ages are the mean-square values calculated using all available evaluations from different color-magnitude diagrams. ... There are individual pages for every cluster where all available plots and parameters are published. ... 2002). ...

Three different forms are possible for representing Results of calculation of spherical coordinates: . the form designated as EMP is similar to that used in the Ephemerides of Minor Planets, having formal precision of 0.01 minute of time in right ascension and 0.1 minute of arc in declination. Longitude, latitude, azimuth and altitude are also displayed with comparable formal precision. the form designated as Positions has enhanced formal precision. ...

... Classes . ... Nebula Class Reference . ... getInfoString (const StelCore *core, const InfoStringGroup &flags) const . ... getCloseViewFov (const StelCore *core=NULL) const . ... getVMagnitude (const StelCore *core, bool withExtinction=false) const . ... getSelectPriority (const StelCore *core) const . ... getEquinoxEquatorialPos (const StelCore *core) const . ... getJ2000GalacticPos (const StelCore *core) const . ... getPositionInfoString (const StelCore *core, const InfoStringGroup &flags) const . ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

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. ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

Describes how spatial region boundaries are handled. The golden rule for spatial region filtering was first enunciated by Leon VanSpeybroeck in 1986: . ... With this in mind, the rules for determining whether a boundary image pixel or table row are assigned to a region are defined below. For image filtering, pixels whose center is inside the boundary are included. ... That is, an row is inside the boundary without regard to its integerized pixel value. ...

Set the display of the status bar, tool bar, locator bar, and properties associated with the display of the pointer position in the Locator bar. ... Set fixed point . ... When the fixed point is set, and the display format is (DX, DY), (DIST), or (R, Theta) then give the location relative to the fixed point. ... Set the fixed point to (0.0, 0.0). ... DX, DY] Display the delta in X and Y of the position of the mouse relative to the fixed point, or (0, 0) if no fixed point has been selected. ...

Classroom Activity: Pinhole Protractor Gene Byrd and Renato Dupke . ... We cannot directly perceive the distances or sizes of far-away objects. Instead, our eyes only detect the angular size of objects. ... In Part II, which will appear in a future issue of The Universe in the Classroom, students will see how astronomers use parallax -- an extension of binocular vision -- to determine the distances of stars in the Sun's neighborhood. ... distance = 57.3 x physical size angular size (in degrees). ...

... 4 2 Trajectory Definition.. ... 5 3 Control Loop Parameters.. ... 7 4.1 OPD datum.. ... If we assume that the trajectory calculation is performed by the DLCS (our recommended implementation), the following commands from the ICS would be used to control the delay line trajectories: Command Track target (sidereal trajectory ) Go to position Query position Stop Constant velocity Go to datum Query OPD offset Set OPD offset Fringe search Parameters Apparent RA dec ...