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author | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
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committer | Joseph Hunkeler <jhunkeler@gmail.com> | 2015-07-08 20:46:52 -0400 |
commit | fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 (patch) | |
tree | bdda434976bc09c864f2e4fa6f16ba1952b1e555 /pkg/images/imcoords/doc/ccfind.hlp | |
download | iraf-linux-fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4.tar.gz |
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diff --git a/pkg/images/imcoords/doc/ccfind.hlp b/pkg/images/imcoords/doc/ccfind.hlp new file mode 100644 index 00000000..33eceb7c --- /dev/null +++ b/pkg/images/imcoords/doc/ccfind.hlp @@ -0,0 +1,596 @@ +.help ccfind Jun99 images.imcoords +.ih +NAME +ccfind -- locate objects in an image given a celestial coordinate list and +the image wcs +.ih +USAGE +ccfind input output image +.ih +PARAMETERS +.ls input +The list of input celestial coordinate files. Coordinates may be entered +by hand by setting input to "STDIN". A STDIN coordinate list is terminated +by typing <EOF> (usually <ctrl/d> or <ctrl/z>). +.le +.ls output +The list of output matched coordinate files. The computed pixel values +are appended to the input coordinate file line and written to output. The number +of output files must equal the number of input files. Results may be +printed on the terminal by setting output to "STDOUT". +.le +.ls image +The list of input images associated with the input coordinate files. The number +of input images must equal the number of input coordinate files. +.le +.ls lngcolumn = 1, latcolumn = 2 +The input coordinate file columns containing the celestial ra / longitude and +dec / latitude coordinates respectively. +.le +.ls lngunits = "", latunits = "" +The units of the input ra / longitude and dec / latitude coordinates. The +options are "hours", "degreees", and "radians" for ra / longitude and +"degrees" and "radians" for dec / latitude. If lngunits and latunits are +undefined they default to the preferred units for the coordinates +system specified by \fIinsystem\fR, e.g. "hours" and "degrees" for +equatorial systems and "degrees" and "degrees" for ecliptic, galactic, and +supergalactic systems. +.le +.ls insystem = "j2000" +The input celestial coordinate system. The \fIinsystem\fR parameter +sets the preferred units for the input celestial coordinates, and +tells CCFIND how to transform the input celestial coordinates +the input image celestial coordinate system. The systems of most +interest to users are "icrs", "j2000", and "b1950". The full set +of options are the following: + +.ls equinox [epoch] +The equatorial mean place post-IAU 1976 (FK5) system if equinox is a +Julian epoch, e.g. J2000.0 or 2000.0, or the equatorial mean place +pre-IAU 1976 system (FK4) if equinox is a Besselian epoch, e.g. B1950.0 +or 1950.0. Julian equinoxes are prefixed by a J or j, Besselian equinoxes +by a B or b. Equinoxes without the J / j or B / b prefix are treated as +Besselian epochs if they are < 1984.0, Julian epochs if they are >= 1984.0. +Epoch is the epoch of the observation and may be a Julian +epoch, a Besselian epoch, or a Julian date. Julian epochs +are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to the epoch type of +equinox if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. If undefined epoch defaults to equinox. +.le +.ls icrs [equinox] [epoch] +The International Celestial Reference System (ICRS) where equinox is +a Julian or Besselian epoch e.g. J2000.0 or B1980.0. +Equinoxes without the J / j or B / b prefix are treated as Julian epochs. +The default value of equinox is J2000.0. +Epoch is a Besselian epoch, a Julian epoch, or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. If undefined epoch defaults to equinox. +.le +.ls fk5 [equinox] [epoch] +The equatorial mean place post-IAU 1976 (FK5) system where equinox is +a Julian or Besselian epoch e.g. J2000.0 or B1980.0. +Equinoxes without the J / j or B / b prefix are treated as Julian epochs. +The default value of equinox is J2000.0. +Epoch is a Besselian epoch, a Julian epoch, or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. If undefined epoch defaults to equinox. +.le +.ls fk4 [equinox] [epoch] +The equatorial mean place pre-IAU 1976 (FK4) system where equinox is a +Besselian or Julian epoch e.g. B1950.0 or J2000.0, +and epoch is the Besselian epoch, the Julian epoch, or the Julian date of the +observation. +Equinoxes without the J / j or B / b prefix are treated +as Besselian epochs. The default value of equinox is B1950.0. Epoch +is a Besselian epoch, a Julian epoch, or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. If undefined epoch defaults to equinox. +.le +.ls noefk4 [equinox] [epoch] +The equatorial mean place pre-IAU 1976 (FK4) system but without the E-terms +where equinox is a Besselian or Julian epoch e.g. B1950.0 or J2000.0, +and epoch is the Besselian epoch, the Julian epoch, or the Julian date of the +observation. +Equinoxes without the J / j or B / b prefix are treated +as Besselian epochs. The default value of equinox is B1950.0. +Epoch is a Besselian epoch, a Julian epoch, or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian day. If undefined epoch defaults to equinox. +.le +.ls apparent epoch +The equatorial geocentric apparent place post-IAU 1976 system where +epoch is the epoch of observation. +Epoch is a Besselian epoch, a Julian epoch or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian +epochs if the epoch value < 1984.0, Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. +.le +.ls ecliptic epoch +The ecliptic coordinate system where epoch is the epoch of observation. +Epoch is a Besselian epoch, a Julian epoch, or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian epochs +if the epoch values < 1984.0, Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian day. +.le +.ls galactic [epoch] +The IAU 1958 galactic coordinate system. +Epoch is a Besselian epoch, a Julian epoch or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian +epochs if the epoch value < 1984.0, Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. The default value of epoch is B1950.0. +.le +.ls supergalactic [epoch] +The deVaucouleurs supergalactic coordinate system. +Epoch is a Besselian epoch, a Julian epoch or a Julian date. +Julian epochs are prefixed by a J or j, Besselian epochs by a B or b. +Epochs without the J / j or B / b prefix default to Besselian +epochs if the epoch value < 1984.0, Julian epochs +if the epoch value <= 3000.0, otherwise epoch is interpreted as +a Julian date. The default value of epoch is B1950.0. +.le + +In all the above cases fields in [] are optional with the defaults as +described. The epoch field for the icrs, fk5, galactic, and supergalactic +coordinate systems is only used if the input coordinates are in the +equatorial fk4, noefk4, fk5, or icrs systems and proper motions are supplied. +Since CCFIND does not currently support proper motions these fields are +not required. +.le +.ls usewcs = no +Use image header information to compute the input image celestial coordinate +system ? If usewcs is "yes", the image coordinate system is read from the +image header. If usewcs is "no", the input image celestial coordinates +system is defined by \fIxref\fR, \fIyref\fR, \fIxmag\fR, \fIymag\fR, +\fIxrotation\fR, \fIyrotation\fR, \fIlngref\fR, \fIlatref\fR, +\fIlngrefunits\fR, \fIlatrefunits\fR, \fIrefsystem\fR, and \fIprojection\fR +parameters respectively. +.le +.ls xref = INDEF, yref = INDEF +The x and y pixel coordinates of the reference point. +xref and yref default to the center of the image in pixel coordinates. +.le +.ls xmag = INDEF, ymag = INDEF +The x and y scale factors in arcseconds per pixel. xmag and ymag default +to 1.0 and 1.0 arcseconds per pixel. +.le +.ls xrotation = INDEF, yrotation = INDEF +The x and y rotation angles in degrees. xrotation and yrotation are +interpreted as the rotation of the ra / longitude and dec / latitude +coordinates with respect to the x and y axes, and default 0.0 and 0.0 degrees +respectively. To set east to the up, down, left, and right directions, +set xrotation to 90, 270, 180, and 0 respectively. To set north to the +up, down, left, and right directions, set yrotation to 0, 180, 90, and 270 +degrees respectively. Any global rotation must be added to both the +xrotation and yrotation values. +.le +.ls lngref = "INDEF", latref = "INDEF" +The ra / longitude and dec / latitude of the reference point. Lngref and latref +may be numbers, e.g 13:20:42.3 and -33:41:26, or keywords for the +appropriate parameters in the image header, e.g. RA and DEC for NOAO +image data. If lngref and latref are undefined they default to 0.0 and 0.0 +respectively. +.le +.ls lngrefunits = "", latrefunits = "" +The units of the reference point celestial coordinates. The options +are "hours", "degrees", and "radians" for the ra / longitude coordinates, +and "degrees" and "radians" for the dec /latitude coordinates. +If lngrefunits and latrefunits are undefined they default to the preferred +units of the reference system. +.le +.ls refsystem = "INDEF" +The celestial coordinate system of the reference point. Refsystem may +be any one of the options listed under the \fIinsystem\fR parameter, e.g. +"b1950", or an image header keyword containing the epoch of the observation +in years, e.g. EPOCH for NOAO data. If refsystem is undefined +the celestial coordinate system of the reference point defaults to the +celestial coordinate system of the input coordinates \fIinsystem\fR. +.le +.ls projection = "tan" +The sky projection geometry. The most commonly used projections in +astronomy are "tan", "arc", "sin", and "lin". Other supported projections +are "ait", "car", "csc", "gls", "mer", "mol", "par", "pco", "qsc", "stg", +"tsc", and "zea". +.le +.ls center = yes +Center the object pixel coordinates using an x and y marginal centroiding +algorithm ? +.le +.ls sbox = 21 +The search box width in pixels. Sbox defines the region of the input image +searched and used to compute the initial x and y marginal centroids. Users +worried about contamination can set sbox = cbox, so that the first +centering iteration will be the same as the others. +.le +.ls cbox = 9 +The centering box width in pixels. Cbox defines the region of the input +image used to compute the final x and y marginal centroids. +.le +.ls datamin = INDEF, datamax = INDEF +The minimum and maximum good data values. Values outside this range +are exclude from the x and y marginal centroid computation. +.le +.ls background = INDEF +The background value used by the centroiding algorithm. If background is +INDEF, a value equal to the mean value of the good data pixels for +each object is used. +.le +.ls maxiter = 5 +The maximum number of centroiding iterations to perform. The centroiding +algorithm will halt when this limit is reached or when the desired tolerance +is reached. +.le +.ls tolerance = 0 +The convergence tolerance of the centroiding algorithm. Tolerance is +defined as the maximum permitted integer shift of the centering box in +pixels from one iteration to the next. +.le +.ls verbose +Print messages about actions taken by the task? +.le + +.ih +DESCRIPTION + +CCFIND locates the objects in the input celestial coordinate lists \fIinput\fR +in the input images \fIimage\fR using the image world coordinate system, +and writes the located objects to the output matched coordinates files +\fIoutput\fR. CCFIND computes the pixel coordinates of each object by, +1) transforming the input celestial coordinates to image celestial coordinate +system, 2) using the image celestial coordinate system to compute the +initial pixel coordinates, and 3) computing the final pixel coordinates +using a centroiding algorithm. The image celestial coordinate system may +be read from the image header or supplied by the user. The CCFIND output +files are suitable for input to the plate solution computation task CCMAP. + +The input ra / longitude and dec / latitude coordinates are read from +columns \fIlngcolumn\fR and \fIlatcolumn\fR in the input coordinate +file respectively. + +The input celestial coordinate system is set by the \fIinsystem\fR parameter, +and must be one of the following: equatorial, ecliptic, galactic, or +supergalactic. The equatorial coordinate systems must be one of: 1) FK4, +the mean place pre-IAU 1976 system, 2) FK4-NO-E, the same as FK4 but without +the E-terms, 3) FK5, the mean place post-IAU 1976 system, 4) ICRS the +International Celestial Reference System, 5) GAPPT, the geocentric apparent +place in the post-IAU 1976 system. + +The \fIlngunits\fR and \fIlatunits\fR parameters set the units of the input +celestial coordinates. If undefined, lngunits and latunits assume sensible +defaults for the input celestial coordinate system set by the \fIinsystem\fR +parameter, e.g. "hours" and "degrees" for equatorial coordinates and "degrees" +and "degrees" for galactic coordinates. + +If the \fIusewcs\fR parameter is "yes", the image celestial coordinate +system is read from the image header keywords CRPIX, CRVAL, CD or CDELT/CROTA, +RADECSYS, EQUINOX or EPOCH, and MJD-OBS or DATE-OBS, where the mathematical +part of this transformation is shown below. + +.nf + xi = a + b * x + c * y + eta = d + e * x + f * y + b = CD1_1 + c = CD1_2 + e = CD2_1 + f = CD2_2 + a = - b * CRPIX1 - c * CRPIX2 + d = - e * CRPIX1 - f * CRPIX2 + lng = CRVAL1 + PROJ (xi, eta) + lat = CRVAL2 + PROJ (xi, eta) +.fi + +If usewcs is "no", then the image celestial coordinate system is computed +using the values of the \fIxref\fR, \fIyref\fR, \fIxmag\fR, \fIymag\fR, +\fIxrotation\fR, \fIyrotation\fR, \fIlngref\fR, \fIlatref\fR, +\fIlngrefunits\fR, \fIlatrefunits\fR, \fIrefsystem\fR, and \fIprojection\fR +supplied by the user, where the mathematical part of this transformation is +shown below. + +.nf + xi = a + b * x + c * y + eta = d + e * x + f * y + b = xmag * cos (xrotation) + c = -ymag * sin (yrotation) + e = xmag * sin (xrotation) + f = ymag * cos (yrotation) + a = - b * xref - c * yref + d = - e * xref - f * yref + lng = lngref + PROJ (xi, eta) + lat = latref + PROJ (xi, eta) +.fi + +In both the above examples, x and y are the pixel coordinates, xi and eta +are the usual projected (standard) coordinates, lng and lat are the celestial +coordinates, and PROJ stands for the projection function, usually +the tangent plane projection function. + +Once the image celestial coordinate system is determined, CCFIND transforms +the input celestial coordinates to the image celestial coordinate system +using the value of the \fIinsystem\fR parameter, and either the values of +the image header keywords RADECSYS, EQUINOX / EPOCH, and MJD-OBS / DATE-OBS +(if \fIusewcs\fR = "yes"), or the value of the \fIrefsystem\fR parameter (if +\fIusewcs\fR = "no"), and then transforms the image celestial coordinates +to pixel coordinates using the inverse of the transformation functions +shown above. + +If \fIcenter\fR is yes, CCFIND locates the objects in the input +image using an xn and y marginal centroiding algorithm. Pixels +inside a box \fIsbox\fR pixels wide centered in the initial coordinates, +are used to locate the objects in the image. Accurate final centering +is done using pixels inside a region \fIcbox\fR pixels wide centered on +these initial coordinates. Sbox should be set to a value large enough +to locate the object, but small enough to exclude other bright sources. +Cbox should be set to a value small enough to exclude sky values and other +bright sources, but large enough to include the wings of point sources. +Bad data can be excluded from the centroiding algorithm by setting +the \fIdatamin\fR and \fIdatamax\fR parameters. If \fIbackground\fR is +undefined then the centroiding algorithm sets the background value to +the mean of the good data values inside the centering box. +The centroiding algorithm iterates until the maximum number of +iterations \fImaxiter\fR limit is reached, or until the tolerance +criteria \fItolerance\fR is achieved. + +Only objects whose coordinates are successfully located in the +input image are written to the output coordinate file. The computed +output pixel coordinates are appended to the input image line using +the format parameters \fIxformat\fR and \fIyformat\fR parameters, +whose default values are "%10.3f" and "%10.3f" respectively + +.ih +FORMATS + +A format specification has the form "%w.dCn", where w is the field +width, d is the number of decimal places or the number of digits of +precision, C is the format code, and n is radix character for +format code "r" only. The w and d fields are optional. The format +codes C are as follows: + +.nf +b boolean (YES or NO) +c single character (c or '\c' or '\0nnn') +d decimal integer +e exponential format (D specifies the precision) +f fixed format (D specifies the number of decimal places) +g general format (D specifies the precision) +h hms format (hh:mm:ss.ss, D = no. decimal places) +m minutes, seconds (or hours, minutes) (mm:ss.ss) +o octal integer +rN convert integer in any radix N +s string (D field specifies max chars to print) +t advance To column given as field W +u unsigned decimal integer +w output the number of spaces given by field W +x hexadecimal integer +z complex format (r,r) (D = precision) + + +Conventions for w (field width) specification: + + W = n right justify in field of N characters, blank fill + -n left justify in field of N characters, blank fill + 0n zero fill at left (only if right justified) +absent, 0 use as much space as needed (D field sets precision) + +Escape sequences (e.g. "\n" for newline): + +\b backspace (not implemented) +\f formfeed +\n newline (crlf) +\r carriage return +\t tab +\" string delimiter character +\' character constant delimiter character +\\ backslash character +\nnn octal value of character + +Examples + +%s format a string using as much space as required +%-10s left justify a string in a field of 10 characters +%-10.10s left justify and truncate a string in a field of 10 characters +%10s right justify a string in a field of 10 characters +%10.10s right justify and truncate a string in a field of 10 characters + +%7.3f print a real number right justified in floating point format +%-7.3f same as above but left justified +%15.7e print a real number right justified in exponential format +%-15.7e same as above but left justified +%12.5g print a real number right justified in general format +%-12.5g same as above but left justified + +%h format as nn:nn:nn.n +%15h right justify nn:nn:nn.n in field of 15 characters +%-15h left justify nn:nn:nn.n in a field of 15 characters +cctran.hlp-(67%)-line 268-file 1 of 1 +%12.2h right justify nn:nn:nn.nn +%-12.2h left justify nn:nn:nn.nn + +%H / by 15 and format as nn:nn:nn.n +%15H / by 15 and right justify nn:nn:nn.n in field of 15 characters +%-15H / by 15 and left justify nn:nn:nn.n in field of 15 characters +%12.2H / by 15 and right justify nn:nn:nn.nn +%-12.2H / by 15 and left justify nn:nn:nn.nn + +\n insert a newline +.fi + +.ih +EXAMPLES + +1. Locate the object in the list wpix.coords in the image wpix using +the existing image header wcs. The input celestial coordinates file +contains j2000 GSC catalog coordinates of 5 objects in the field. +The image wcs is in b1950. + +.nf +cl> imcopy dev$wpix wpix + ... copy the test image into the current directory + +cl> hedit wpix equinox 1950.0 add+ + ... change the epoch keyword value to the correct number + +cl> type wpix.coords +13:29:47.297 47:13:37.52 +13:29:37.406 47:09:09.18 +13:29:38.700 47:13:36.23 +13:29:55.424 47:10:05.15 +13:30:01.816 47:12:58.79 + +cl> ccfind wpix.coords wpix.match wpix usewcs+ + +Input File: wpix.coords Output File: wpix.match + Image: wpix Wcs: +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +Refsystem: wpix.imh logical Projection: TAN Ra/Dec axes: 1/2 + Coordinates: equatorial FK4 Equinox: B1950.000 + Epoch: B1987.25767884 MJD: 46890.00000 +Located 5 objects in image wpix + +cl> type wpix.match +# Input File: wpix.coords Output File: wpix.match +# Image: wpix Wcs: +# Insystem: j2000 Coordinates: equatorial FK5 +# Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +# Refsystem: wpix.imh logical Projection: TAN Ra/Dec axes: 1/2 +# Coordinates: equatorial FK4 Equinox: B1950.000 +# Epoch: B1987.25767884 MJD: 46890.00000 + +13:29:47.297 47:13:37.52 327.504 410.379 +13:29:37.406 47:09:09.18 465.503 62.101 +13:29:38.700 47:13:36.23 442.013 409.654 +13:29:55.424 47:10:05.15 224.351 131.200 +13:30:01.816 47:12:58.79 134.373 356.327 + +cl> ccmap wpix.match ccmap.db xcol=3 ycol=4 lngcol=1 latcol=2 ... +.fi + +2. Repeat the previous example but input the image coordinate system by hand. +The scale is known to be ~0.77 arcseconds per pixel, north is up, east is left, +and the center of the image is near ra = 13:27:47, dec = 47:27:14 in 1950 +coordinates. + +.nf +cl> ccfind wpix.coords wpix.match wpix xmag=-0.77 ymag=.77 lngref=13:27:47 \ +latref=47:27:14 refsystem=b1950. + +Input File: wpix.coords Output File: wpix.match.1 + Image: wpix Wcs: +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +Refsystem: b1950 Coordinates: equatorial FK4 + Equinox: B1950.000 Epoch: B1950.00000000 MJD: 33281.92346 +Located 5 objects in image wpix + + +cl> type wpix.match + +# Input File: wpix.coords Output File: wpix.match +# Image: wpix Wcs: +# Insystem: j2000 Coordinates: equatorial FK5 +# Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +# Refsystem: b1950 Coordinates: equatorial FK4 +# Equinox: B1950.000 Epoch: B1950.00000000 MJD: 33281.92346 + +13:29:47.297 47:13:37.52 327.504 410.379 +13:29:37.406 47:09:09.18 465.503 62.101 +13:29:38.700 47:13:36.23 442.013 409.654 +13:29:55.424 47:10:05.15 224.351 131.200 +13:30:01.816 47:12:58.79 134.373 356.327 +.fi + +3. Repeat the previous example but read the ra, dec, and epoch from the +image header keywords RA, DEC, and EPOCH. It turns out the telescope +RA and DEC recorded in the image header are not very accurate and that +EPOCH is 0.0 instead of 1987.26 so we will fix up the header before +trying out the example. + +.nf +cl> hedit wpix EPOCH 1987.26 +cl> hedit wpix RA '13:29:21' +cl> hedit wpix DEC '47:15:42' + +cl> ccfind wpix.coords wpix.match wpix xmag=-0.77 ymag=.77 lngref=RA \ +latref=DEC refsystem=EPOCH + +Input File: wpix.coords Output File: wpix.match + Image: wpix Wcs: +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +Refsystem: 1987.26 Coordinates: equatorial FK5 + Equinox: J1987.260 Epoch: J1987.26000000 MJD: 46891.21500 +Located 5 objects in image wpix + +# Input File: wpix.coords Output File: wpix.match +# Image: wpix Wcs: +# Insystem: j2000 Coordinates: equatorial FK5 +# Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +# Refsystem: 1987.26 Coordinates: equatorial FK5 +# Equinox: J1987.260 Epoch: J1987.26000000 MJD: 46891.21500 + +13:29:47.297 47:13:37.52 327.504 410.379 +13:29:37.406 47:09:09.18 465.503 62.101 +13:29:38.700 47:13:36.23 442.013 409.654 +13:29:55.424 47:10:05.15 224.351 131.200 +13:30:01.816 47:12:58.79 134.373 356.327 +.fi + +4. Use ccfind to predict the pixel coordinate in the last example by +turning off the object centering, and mark the predicted coordinates +on the image display with red dots. + +.nf +cl> ccfind wpix.coords wpix.match wpix xmag=-0.77 ymag=.77 lngref=RA \ +latref=DEC refsystem=EPOCH center- + +Input File: wpix.coords Output File: wpix.match + Image: wpix Wcs: +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +Refsystem: 1987.26 Coordinates: equatorial FK5 + Equinox: J1987.260 Epoch: J1987.26000000 MJD: 46891.21500 +Located 5 objects in image wpix + +cl> type wpix.match + +# Input File: wpix.coords Output File: wpix.match +# Image: wpix Wcs: +# Insystem: j2000 Coordinates: equatorial FK5 +# Equinox: J2000.000 Epoch: J2000.00000000 MJD: 51544.50000 +# Refsystem: 1987.26 Coordinates: equatorial FK5 +# Equinox: J1987.260 Epoch: J1987.26000000 MJD: 46891.21500 + +13:29:47.297 47:13:37.52 333.954 401.502 +13:29:37.406 47:09:09.18 465.338 53.175 +13:29:38.700 47:13:36.23 447.687 399.967 +13:29:55.424 47:10:05.15 226.600 125.612 +13:30:01.816 47:12:58.79 141.892 351.084 + +cl> display wpix 1 + +cl> fields wpix.match 3,4 | tvmark 1 STDIN col=204 + +.fi + +.ih +TIME REQUIREMENTS +.ih +BUGS +.ih +SEE ALSO +starfind, ccxymatch, ccmap, ccsetwcs, cctran +.endhelp |