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diff --git a/pkg/images/imcoords/doc/ccxymatch.hlp b/pkg/images/imcoords/doc/ccxymatch.hlp new file mode 100644 index 00000000..6987a437 --- /dev/null +++ b/pkg/images/imcoords/doc/ccxymatch.hlp @@ -0,0 +1,781 @@ +.help ccxymatch Oct96 images.imcoords +.ih +NAME +ccxymatch -- Match celestial and pixel coordinate lists using various methods +.ih +USAGE +ccxymatch input reference output tolerance [ptolerance] +.ih +PARAMETERS +.ls input +The list of input pixel coordinate files. +.le +.ls reference +The list of input celestial coordinate files. The number of celestial coordinate +files must be one or equal to the number of pixel coordinate files. +.le +.ls output +The output matched coordinate files containing: 1) the celestial coordinates +of the matched objects in columns 1 and 2, 2) the pixel coordinates of the +matched objects in columns 3 and 4, and 3) the line numbers of the matched +objects in the celestial coordinate and pixel lists in columns 5 and 6. +.le +.ls tolerance +The matching tolerance in arcseconds. +.le +.ls ptolerance +The matching tolerance in pixels. The ptolerance parameter is required +by the "triangles" matching algorithm but not by the "tolerance" matching +algorithm. +.le +.ls refpoints = "" +A file of tie points used to compute the linear transformation +from the pixel coordinate system to the celestial coordinate system. Refpoints +is a text file containing the celestial coordinates of 1-3 tie points +in the first line, followed by the pixel coordinates of the same 1-3 tie points +in succeeding lines. The celestial coordinates are assumed to be +in the units specified by \fIlngunits\fR and \fIlatunits\fR. +If refpoints is undefined then the parameters \fIxin\fR, \fIyin\fR, +\fIxmag\fR, \fIymag\fR, \fIxrotation\fR, \fIyrotation\fR, \fIprojection\fR, +\fIlngref\fR, and \fIlatref\fR are used to compute the linear transformation. +.le +.ls xin = INDEF, yin = INDEF +The x and y origin of the pixel coordinate system. Xin and yin default to +0.0 and 0.0 respectively. +.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 respectively. +.le +.ls xrotation = INDEF, yrotation = INDEF +The x and y rotation angles measured in degrees counter-clockwise. Xrotation +and yrotation default to 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 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 lngref = INDEF, latref = INDEF +The origin of the celestial coordinate system. Lngref and latref define the +reference point of the sky projection \fIprojection\fR, and default to the +mean of the ra / longitude and dec / latitude coordinates respectively. Lngref +and latref are assumed to be in units of \fIlngunits\fR and \fIlatunits\fR. +.le +.ls lngcolumn = 1, latcolumn = 2 +The columns in the celestial coordinate list containing the ra / longitude +and dec / latitude coordinate values. +.le +.ls xcolumn = 1, ycolumn = 2 +The columns in the pixel coordinate list containing the x and y coordinate +values. +.le +.ls lngunits = "hours", latunits = "degrees" +The units of the celestial coordinates. The options are "hours", "degrees", +and "radians" for lngunits, and "degrees" and "radians" for latunits. +.le +.ls separation = 3.0 +The minimum separation in arcseconds for objects in the celestial coordinate +lists. Objects closer together than separation arcseconds +are removed from the celestial coordinate lists prior to matching. +.le +.ls pseparation = 9.0 +The minimum separation in pixels for objects in the pixel coordinate +lists. Objects closer together than pseparation pixels +are removed from the pixel coordinate lists prior to matching. +.le +.ls matching = "triangles" +The matching algorithm. The choices are: +.ls tolerance +A linear transformation is applied to the pixel coordinates, +the appropriate projection is applied to the celestial coordinates, +the transformed pixel and celestial coordinates are sorted, +points which are too close together are removed, and the pixel coordinates +which most closely match the celestial coordinates to within the +user specified tolerance are determined. The tolerance algorithm requires +an initial estimate for the linear transformation. This estimate can be +derived by supplying the coordinates of tie points via the +\fIrefpoints\fR file, or by setting the linear transformation parameters +\fIxin\fR, \fIyin\fR, \fIxmag\fR, \fIymag\fR, \fIxrotation\fR, +\fIyrotation\fR, \fIprojection\fR, \fIlngref\fR, and \fIlatref\fR. Assuming that +a good initial estimate for the required linear transformation is supplied, +the tolerance algorithm functions well in the presence of shifts, axis +flips, x and y scale changes, rotations, and axis skew between the two +coordinate systems. The algorithm is sensitive to higher order distortion terms +in the coordinate transformation. +.le +.ls triangles +A linear transformation is applied to the pixel coordinates, +the appropriate projection is applied to the celestial coordinates, +the transformed pixel and celestial coordinates are sorted, points +which are too close together are removed, and the pixel coordinates +are matched to the celestial coordinates using a triangle pattern +matching algorithm and user specified tolerance parameters. +The triangles pattern matching algorithm does not require prior knowledge +of the linear transformation, although it will use a transformation if one +is supplied. The algorithm functions well in the presence of +shifts, axis flips, magnification, and rotation between the two coordinate +systems, as long as both lists have a reasonable number of objects +in common and the errors in the computed coordinates are small. +However as the algorithm depends on comparisons of similar triangles, it +is sensitive to differences in the x and y coordinate scales, +skew between the x and y axes, and higher order distortion terms +in the coordinate transformation. +.le +.le +.ls nmatch = 30 +The maximum number of celestial and pixel coordinates used +by the "triangles" pattern matching algorithm. If either list contains +more coordinates than nmatch, the lists are subsampled. Nmatch should be +kept small as the computation and memory requirements of the "triangles" +algorithm depend on a high power of the lengths of the respective lists. +.le +.ls ratio = 10.0 +The maximum ratio of the longest to shortest side of the +triangles generated by the "triangles" pattern matching algorithm. +Triangles with computed longest to shortest side ratios > ratio +are rejected from the pattern matching algorithm. Ratio should never +be set higher than 10.0 but may be set as low as 5.0. +.le +.ls nreject = 10 +The maximum number of rejection iterations for the "triangles" pattern +matching algorithm. +.le +.ls lngformat = "", latformat = "" +The format of the output celestial coordinates. The default formats are +"%13.3h", "%13.3h", and "%13.7g" for units of "hours", "degrees", and +"radians" respectively. +.le +.ls xformat = "%13.3f", yformat = "%13.3f" +The format of the output pixel coordinates. +By default the coordinates are output right justified in a field of +13 characters with 3 places following the decimal point. +.le +.ls verbose = yes +Print messages about the progress of the task ? +.le + +.ih +DESCRIPTION + +CCXYMATCH matches ra / dec or longitude / latitude coordinates in the +celestial coordinate list \fIreference\fR to their corresponding x and y +coordinates in the pixel coordinate list \fIinput\fR using user specified +tolerances in arcseconds \fItolerance\fR and pixels \fIptolerance\fR, and +writes the matched coordinates to the output file \fIoutput\fR. The output +file is suitable for input to the plate solution computation task CCMAP. + +CCXYMATCH matches the coordinate lists by: 1) projecting the celestial +coordinates onto a plane using the sky projection geometry \fIprojection\fR +and the reference point \fIlngref\fR and \fIlatref\fR, +2) computing an initial guess for the linear transformation required to +match the pixel coordinate system to the projected celestial coordinate system, +3) applying the computed transformation to the pixel coordinates, 4) sorting +the projected celestial and pixel coordinates lists, 5) removing points with a +minimum separation specified by the parameters \fIseparation\fR and +\fIpseparation\fR from both lists, 6) matching the two lists using either +the "triangles" or "tolerance" matching algorithms, and 7) writing the matched +list to the output file. + +An initial estimate for the linear transformation is computed in one of +two ways. If \fIrefpoints\fR is defined, the celestial and pixel coordinates +of up to three tie points are read from succeeding lines in the refpoints file, +and used to compute the linear transformation. The coordinates of the tie +points can be typed in by hand if \fIrefpoints\fR is "STDIN". The formats of +two sample refpoints files are shown below. + +.nf +# First sample refpoints file (1 reference file and N input files) + +ra1 dec1 [ra2 dec2 [ra3 dec3]] # tie points for reference coordinate file + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file 1 + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file 2 +.. .. [ .. .. [ .. ..] + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file N + + +# Second sample refpoints file (N reference files and N input files) + +ra1 dec1 [ra2 dec2 [ra3 dec3]] # tie points for reference coordinate file 1 + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file 1 +ra1 dec1 [ra2 dec2 [ra3 dec3]] # tie points for reference coordinate file 2 + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file 2 + .. .. [ .. .. [ .. ..]] +ra1 dec1 [ra2 dec2 [ra3 dec3]] # tie points for reference coordinate file N + x1 y1 [ x2 y2 [ x3 y3]] # tie points for input coordinate file N + +.fi + +If the refpoints file is undefined the parameters \fIxin\fR, \fIxin\fR, +\fIxmag\fR, \fIymag\fR, \fIxrotation\fR, \fIxrotation\fR are used +to compute a linear transformation from the pixel coordinates to the +standard coordinates xi and eta as shown below. Orientation and skew +are the orientation of the x and y axes and their deviation from +perpendicularity respectively. + + +.nf + xi = a + b * x + c * y + eta = d + e * x + f * y + + xrotation = orientation - skew / 2 + yrotation = orientation + skew / 2 + b = xmag * cos (xrotation) + c = -ymag * sin (yrotation) + e = xmag * sin (xrotation) + f = ymag * cos (yrotation) + a = 0.0 - b * xin - c * yin = xshift + d = 0.0 - e * xin - f * yin = yshift +.fi + +Both methods of computing the initial linear transformation compute the +standard coordinates xi and eta by projecting the celestial coordinates +onto a plane using the sky projection geometry \fIprojection\fR and the +reference point \fIlngref\fR and \fIlatref\fR. The celestial coordinates +are assumed to be in units of \fIlngunits\fR and \fIlatunits\fR and the +standard coordinates are in arcseconds. The linear transformation and its +geometric interpretation are shown below. + +The celestial and pixel coordinates are read from columns \fIlngcolumn\fR and +\fIlatcolumn\fR in the celestial coordinate list, and \fIxcolumn\fR, and +\fIycolumn\fR in the pixel coordinate list respectively. The pixel +coordinates are transformed using the linear transformation described above, +the celestial coordinate in units of \fIlngunits\fR and \fIlatunits\fR +are projected to standard coordinates in arcseconds, and stars closer together +than \fIseparation\fR arcseconds and \fIpseparation\fR pixels are removed +from the celestial and pixel coordinate lists respectively. + +The coordinate lists are matched using the matching algorithm specified by +\fImatching\fR. If matching is "tolerance", CCXYMATCH searches the transformed +sorted pixel coordinate list for the coordinates that are within the matching +tolerance \fItolerance\fR and closest to the current standard coordinates. +The major advantage of the "tolerance" algorithm is that it can handle x and y +scale differences and axis skew in the coordinate transformation. The major +disadvantage of the "tolerance" algorithm is that the user must supply +tie point information in all but the simplest case of small x and y +shifts between the pixel and celestial coordinate systems. + +If matching is "triangles", CCXYMATCH constructs a list of triangles +using up to \fInmatch\fR celestial coordinates and transformed pixel +coordinates and performs a pattern matching operation on the resulting +triangle lists. If the number of coordinates in both lists is less than +\fInmatch\fR the entire list is matched using the "triangles" algorithm +directly, otherwise the "triangles" algorithm is used to estimate a new +linear transformation, the input coordinate list is transformed using +the new transformation, and the entire list is matched using the "tolerance" +algorithm. The major advantage of the "triangles" algorithm is that it +requires no tie point information from the user. The major disadvantages of the +algorithm are that, it is sensitive to x and y scale differences and axis +skew between the celestial and pixel coordinate systems, and can be +computationally expensive. + +The matched celestial and pixel coordinates are written to columns 1, 2, 3, +and 4 of the output file, in the formats specified by the \fIlngformat\fR, +\fIlatformat\fR, \fIxformat\fR and \fIyformat\fR parameters. The original +line numbers in the celestial and pixels coordinate files are written to +columns 5 and 6. + +If \fIverbose\fR is yes, detailed messages about actions taken by the +task are written to the terminal as the task executes. + +.ih +ALGORITHMS + +The "triangles" algorithm uses a sophisticated pattern matching +technique which requires no tie point information from the user. +It is expensive computationally and is therefore restricted to a maximum +of \fInmatch\fR objects from the celestial and pixel coordinate lists. + +The "triangles" algorithm first generates a list +of all the possible triangles that can be formed from the points in each list. +For a list of nmatch points this number is the combinatorial factor +nmatch! / [(nmatch-3)! * 3!] or nmatch * (nmatch-1) * (nmatch-2) / 6. +The length of the perimeter, ratio of longest to shortest side, cosine +of the angle between the longest and shortest side, the tolerances in +the latter two quantities and the direction of the arrangement of the vertices +of each triangle are computed and stored in a table. +Triangles with vertices closer together than \fItolerance\fR and +\fIptolerance\fR, or +with a ratio of the longest to shortest side greater than \fIratio\fR +are discarded. The remaining triangles are sorted in order of increasing +ratio. A sort merge algorithm is used to match the triangles using the +ratio and cosine information, the tolerances in these quantities, and +the maximum tolerances for both lists. The ratios of the +perimeters of the matched triangles are compared to the most common ratio +for the entire list, and triangles which deviate too widely from this number +are discarded. The number of triangles remaining are divided into +the number which match in the clockwise sense and the number which match +int the counter-clockwise sense. Those in the minority category +are eliminated. +The rejection step can be repeated up to \fInreject\fR times or until +no more rejections occur, whichever comes first. +The last step in the algorithm is a voting procedure in which each remaining +matched triangle casts three votes, one for each matched pair of vertices. +Points which have fewer than half the maximum number of +votes are discarded. The final set of matches are written to the output file. + +The "triangles" algorithm functions well when the celestial and +pixel coordinate lists have a sufficient number of objects (50%, +in some cases as low as 25%) of their objects in common, any distortions +including x and y scale differences and skew between the two systems are small, +and the random errors in the coordinates are small. Increasing the value of +the \fItolerance\fR parameter will increase the ability to deal with +distortions but will also produce more false matches which after some point +will swamp the true matches. + +.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 +%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 +REFERENCES + +A detailed description of the "triangles" pattern matching algorithm used here +can be found in the article "A Pattern-Matching Algorithm for Two- +Dimensional Coordinate Lists" by E.J. Groth, A.J. 91, 1244 (1986). + +.ih +EXAMPLES + +1. Compute the plate solution for a 1528 by 2288 B band image of M51 by +matching a list of reference stars extracted from the Guide Star Catalog +with the regions task against a list of bright stars detected with the daofind +task. The approximate image center is RA = 13:29:52.8 and DEC = +47:11:41 +(J2000) and the image scale is 0.43 arcseconds / pixel. + +.nf +... Get the guide stars (see stsdas.analysis.gasp package). +cl> regions 13:29:52.8 47:11:41 0.27 m51b.gsc.tab + +... Convert the binary table to a text file (see package tables.ttools). +cl> tprint m51b.gsc.tab > m51b.gsc + +... Examine the guide star list. +cl> type m51b.gsc + +# Table m51b.gsc.tab Tue 10:39:55 22-Oct-96 + +# row RA_HRS RA_DEG DEC_DEG MAG +# hours degrees degrees magnitudes + + 1 13:29:13.33 202:18:19.9 47:14:16.3 12.3 + 2 13:29:05.51 202:16:22.6 47:10:44.7 14.8 + 3 13:29:48.60 202:27:09.0 47:07:42.5 15.0 + 4 13:29:47.30 202:26:49.4 47:13:37.5 10.9 + 5 13:29:31.65 202:22:54.7 47:18:54.7 15.0 + 6 13:29:06.16 202:16:32.4 47:04:53.1 14.9 + 7 13:29:37.40 202:24:21.1 47:09:09.2 15.1 + 8 13:29:38.70 202:24:40.5 47:13:36.2 15.0 + 9 13:29:55.42 202:28:51.3 47:10:05.2 15.4 + 10 13:29:06.91 202:16:43.7 47:04:07.9 12.4 + 11 13:29:29.73 202:22:25.9 47:12:04.1 15.1 + 12 13:30:07.96 202:31:59.4 47:05:18.3 14.7 + 13 13:30:01.82 202:30:27.2 47:12:58.8 11.8 + 14 13:30:36.75 202:39:11.2 47:04:05.9 14.9 + 15 13:30:34.04 202:38:30.6 47:16:44.8 13.2 + 16 13:30:14.95 202:33:44.3 47:10:27.6 13.4 + +... Locate bright stars in the image (see noao.digiphot.daophot package). +... Suitable values for fwhmpsf, sigma, ... and threshold can be determined +... using the imstatistics and imexamine tasks. Some experimentation may be +... necessary to determine optimal values. +cl> daofind m51b "default" fwhmpsf=4.0 sigma=5.0 threshold=20.0 + +... Examine the star list. +cl> type m51b.coo.1 + + ... +#N XCENTER YCENTER MAG SHARPNESS SROUND GROUND ID + ... + 401.034 147.262 -2.315 0.473 -0.075 -0.170 1 + 261.137 453.696 -1.180 0.481 -0.373 -0.135 2 + 860.002 480.061 -1.397 0.373 -0.218 -0.178 3 + 69.342 675.895 -0.955 0.368 -0.294 -0.133 4 + 1127.791 680.033 -1.166 0.449 -0.515 -0.326 5 + 972.435 691.544 -1.722 0.449 -0.327 -0.060 6 + 1348.891 715.084 -1.069 0.389 -0.242 -0.145 7 + 946.114 797.067 -0.543 0.406 -0.198 -0.069 8 + 698.455 811.407 -1.620 0.437 -0.038 -0.028 9 + 964.566 853.201 -0.317 0.382 0.031 -0.086 10 + 236.088 864.817 -3.515 0.429 -0.164 -0.035 11 + 919.703 909.835 -3.775 0.447 0.051 0.007 12 + 406.592 985.807 -0.715 0.424 -0.307 -0.068 13 + 920.790 986.083 -0.600 0.364 -0.047 0.021 14 + 761.403 1037.795 -1.944 0.383 -0.023 0.120 15 + 692.012 1050.603 -0.508 0.339 -0.365 -0.164 16 + 1023.330 1060.144 -1.897 0.381 -0.246 -0.288 17 + 681.864 1066.937 -0.059 0.467 -0.175 0.135 18 + 1307.802 1085.564 -1.173 0.435 0.032 -0.207 19 + 716.494 1094.800 -0.389 0.421 -0.412 -0.032 20 + 715.935 1106.616 -3.747 0.649 0.271 0.245 21 + 1093.813 1300.189 -1.557 0.377 -0.309 -0.078 22 + 596.406 1353.798 -0.461 0.383 0.029 -0.103 23 + 1212.117 1362.636 -0.362 0.369 -0.180 0.043 24 + 251.355 1488.048 -0.909 0.357 -0.390 0.077 25 + 600.659 1630.261 -1.392 0.423 0.013 -0.312 26 + 329.448 2179.233 -0.824 0.442 -0.463 0.325 27 + +... Match the two lists using the "triangles" algorithm and tolerances of +... 1.0 arcseconds and 3.0 pixels respectively. +cl> ccxymatch m51b.coo.1 m51b.gsc m51b.mat.1 1.0 3.0 lngcolumn=2 latcolumn=4 + +... Examine the matched file. +cl> type m51b.mat.1 + +# Input: m51b.coo.1 Reference: m51b.gsc Number of tie points: 0 +# Initial linear transformation +# xref[tie] = 0. + 1. * x[tie] + 0. * y[tie] +# yref[tie] = 0. + 0. * x[tie] + 1. * y[tie] +# dx: 0.00 dy: 0.00 xmag: 1.000 ymag: 1.000 xrot: 0.0 yrot: 0.0 +# +# Column definitions +# Column 1: Reference Ra / Longitude coordinate +# Column 2: Reference Dec / Latitude coordinate +# Column 3: Input X coordinate +# Column 4: Input Y coordinate +# Column 5: Reference line number +# Column 6: Input line number + + 13:29:48.600 47:07:42.50 860.002 480.061 8 44 + 13:29:38.700 47:13:36.20 1093.813 1300.189 13 63 + 13:29:55.420 47:10:05.20 698.455 811.407 14 50 + 13:29:29.730 47:12:04.10 1307.802 1085.564 16 60 + 13:30:07.960 47:05:18.30 401.034 147.262 17 42 + 13:30:14.950 47:10:27.60 236.088 864.817 21 52 + +... Compute the plate solution. +cl> ccmap m51b.mat.1 ccmap.db results=STDOUT xcolumn=3 ycolumn=4 lngcolumn=1 \ +latcolumn=2 refpoint=user lngref=13:29:52.8 latref=47:11:41 interactive=no + +Coords File: m51b.mat.1 Image: + Database: ccmap.db Record: m51b.mat.1 +Refsystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Coordinate mapping status + XI fit ok. ETA fit ok. + Ra/Dec or Long/Lat fit rms: 0.206 0.103 (arcsec arcsec) +Coordinate mapping parameters + Sky projection geometry: tan + Reference point: 13:29:52.800 47:11:41.00 (hours degrees) + Reference point: 760.656 1033.450 (pixels pixels) + X and Y scale: 0.430 0.431 (arcsec/pixel arcsec/pixel) + X and Y axis rotation: 180.158 359.991 (degrees degrees) + + Input Coordinate Listing + X Y Ra Dec Ra(fit) Dec(fit) Dra Ddec + + 860.0 480.1 13:29:48.60 47:07:42.5 13:29:48.62 47:07:42.5 -0.153 0.017 +1093.8 1300.2 13:29:38.70 47:13:36.2 13:29:38.73 47:13:36.4 -0.258 -0.164 + 698.5 811.4 13:29:55.42 47:10:05.2 13:29:55.43 47:10:05.2 -0.062 0.024 +1307.8 1085.6 13:29:29.73 47:12:04.1 13:29:29.70 47:12:04.0 0.318 0.123 + 401.0 147.3 13:30:07.96 47:05:18.3 13:30:07.96 47:05:18.4 0.028 -0.073 + 236.1 864.8 13:30:14.95 47:10:27.6 13:30:14.94 47:10:27.5 0.127 0.073 +.fi + + + +2. Repeat example 1 but replace the daofind pixel list with one generated +using the center task and a finder chart created with the skymap task. + +.nf +... Get the guide stars. (see stsdas.analysis.gasp package) +cl> regions 13:29:52.8 47:11:41 0.27 m51b.gsc.tab + +... Create the finder chart (see stsdas.analysis.gasp package) +cl> gasp.skymap m51b.gsc.tab 13:29:52.8 47:11:41 INDEF 0.27 \ +objstyle=square racol=RA_HRS deccol=DEC_DEG magcol=MAG interactive- \ +dev=stdplot + +... Convert the binary table to a text file. (see tables.ttools package) +cl> tprint m51b.gsc.tab > m51b.gsc + +... Mark and center the guide stars on the image display using the finder +... chart produced by the skymap task and the center task (see the +... digiphot.apphot package). +cl> display m51b 1 fi+ +cl> center m51b cbox=7.0 ... +cl> pdump m51b.ctr.1 xcenter,ycenter yes > m51b.pix + +... Display the pixel coordinate list. +cl> type m51b.pix + +401.022 147.183 +236.044 864.882 +698.368 811.329 +860.003 480.051 +1127.754 680.020 +1307.819 1085.615 +1093.464 1289.595 +1212.001 1362.594 +1348.963 715.085 + +... Match the two lists using the "triangles" algorithm and tolerances of +... 1.0 arcseconds and 3.0 pixels respectively. +cl> ccxymatch m51b.pix m51b.gsc m51b.mat.2 1.0 3.0 lngcolumn=2 latcolumn=4 + +... Examine the matched file. +cl> type m51b.mat.2 + +# Input: m51b.pix Reference: m51b.gsc Number of tie points: 0 +# Initial linear transformation +# xi[tie] = 0. + 1. * x[tie] + 0. * y[tie] +# eta[tie] = 0. + 0. * x[tie] + 1. * y[tie] +# dx: 0.00 dy: 0.00 xmag: 1.000 ymag: 1.000 xrot: 0.0 yrot: 0.0 +# +# Column definitions +# Column 1: Reference Ra / Longitude coordinate +# Column 2: Reference Dec / Latitude coordinate +# Column 3: Input X coordinate +# Column 4: Input Y coordinate +# Column 5: Reference line number +# Column 6: Input line number + + 13:29:48.600 47:07:42.50 860.003 480.051 8 4 + 13:29:37.400 47:09:09.20 1127.754 680.020 12 5 + 13:29:55.420 47:10:05.20 698.368 811.329 14 3 + 13:29:29.730 47:12:04.10 1307.819 1085.615 16 6 + 13:30:07.960 47:05:18.30 401.022 147.183 17 1 + 13:30:14.950 47:10:27.60 236.044 864.882 21 2 + +... Compute the plate solution. +cl> ccmap m51b.mat.2 ccmap.db results=STDOUT xcolumn=3 ycolumn=4 lngcolumn=1 \ +latcolumn=2 refpoint=user lngref=13:29:52.8 latref=47:11:41 interactive=no + +Coords File: m51b.mat.2 Image: + Database: junk.db Record: m51b.mat.2 +Refsystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Coordinate mapping status + XI fit ok. ETA fit ok. + Ra/Dec or Long/Lat fit rms: 0.312 0.0664 (arcsec arcsec) +Coordinate mapping parameters + Sky projection geometry: tan + Reference point: 13:29:52.800 47:11:41.00 (hours degrees) + Reference point: 761.093 1033.230 (pixels pixels) + X and Y scale: 0.430 0.431 (arcsec/pixel arcsec/pixel) + X and Y axis rotation: 180.175 359.998 (degrees degrees) + + Input Coordinate Listing + X Y Ra Dec Ra(fit) Dec(fit) Dra Ddec +.fi + + +3. Repeat example 1 but use the "tolerance" matching algorithm and apriori +knowledge of the celestial and pixel coordinates of the nucleus of M51, +the x and y image scales, and the orientation of the detector on the telescope +to match the two lists. + +.nf +... Match the two lists using the ccxymatch "tolerance" algorithm and +... a matching tolerance of 2.0 arcseconds. Note the negative and positive +... signs on the xmag and ymag parameters and lack of any rotation, +... indicating that north is up and east is to the left. +cl> ccxymatch m51b.coo.1 m51b.gsc m51b.mat.3 2.0 lngcolumn=2 latcolumn=4 \ +matching=tolerance xin=761.40 yin=1037.80 xmag=-0.43 ymag=0.43 xrot=0.0 \ +yrot=0.0 lngref=13:29:52.80 latref=47:11:42.9 + +... Examine the matched file. +cl> type m51b.mat.3 + +# Input: m51b.coo.1 Reference: m51b.gsc Number of tie points: 0 +# Initial linear transformation +# xref[tie] = 327.402 + -0.43 * x[tie] + 0. * y[tie] +# yref[tie] = -446.254 + 0. * x[tie] + 0.43 * y[tie] +# dx: 327.40 dy: -446.25 xmag: 0.430 ymag: 0.430 xrot: 180.0 yrot: 0.0 +# +# Column definitions +# Column 1: Reference Ra / Longitude coordinate +# Column 2: Reference Dec / Latitude coordinate +# Column 3: Input X coordinate +# Column 4: Input Y coordinate +# Column 5: Reference line number +# Column 6: Input line number + + 13:30:07.960 47:05:18.30 401.034 147.262 17 42 + 13:29:48.600 47:07:42.50 860.002 480.061 8 44 + 13:29:37.400 47:09:09.20 1127.791 680.033 12 46 + 13:29:55.420 47:10:05.20 698.455 811.407 14 50 + 13:30:14.950 47:10:27.60 236.088 864.817 21 52 + 13:29:29.730 47:12:04.10 1307.802 1085.564 16 60 + 13:29:38.700 47:13:36.20 1093.813 1300.189 13 63 + + +... Compute the plate solution. +cl> ccmap m51b.mat.3 ccmap.db results=STDOUT xcolumn=3 ycolumn=4 lngcolumn=1 \ +latcolumn=2 refpoint=user lngref=13:29:52.8 latref=47:11:41 interactive=no + +Coords File: m51b.mat.3 Image: + Database: ccmap.db Record: m51.mat.3 +Refsystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Insystem: j2000 Coordinates: equatorial FK5 + Equinox: J2000.000 Epoch: J2000.000 MJD: 51544.50000 +Coordinate mapping status + XI fit ok. ETA fit ok. + Ra/Dec or Long/Lat fit rms: 0.342 0.121 (arcsec arcsec) +Coordinate mapping parameters + Sky projection geometry: tan + Reference point: 13:29:52.800 47:11:41.00 (hours degrees) + Reference point: 760.687 1033.441 (pixels pixels) + X and Y scale: 0.430 0.431 (arcsec/pixel arcsec/pixel) + X and Y axis rotation: 180.174 359.949 (degrees degrees) + + Input Coordinate Listing + X Y Ra Dec Ra(fit) Dec(fit) Dra Ddec + + 401.0 147.3 13:30:07.96 47:05:18.3 13:30:07.97 47:05:18.4 -0.109 -0.109 + 860.0 480.1 13:29:48.60 47:07:42.5 13:29:48.64 47:07:42.5 -0.385 -0.045 +1127.8 680.0 13:29:37.40 47:09:09.2 13:29:37.34 47:09:09.0 0.572 0.152 + 698.5 811.4 13:29:55.42 47:10:05.2 13:29:55.43 47:10:05.2 -0.118 0.009 + 236.1 864.8 13:30:14.95 47:10:27.6 13:30:14.92 47:10:27.5 0.290 0.116 +1307.8 1085.6 13:29:29.73 47:12:04.1 13:29:29.72 47:12:04.0 0.082 0.060 +1093.8 1300.2 13:29:38.70 47:13:36.2 13:29:38.73 47:13:36.4 -0.332 -0.184 +.fi + + + +4. Repeat example 3 but input the appropriate linear transformation via a list +of tie points, rather than setting the transformation parameters directly. + +.nf +... Display the tie points. +cl> type refpts +13:29:55.42 47:10:05.2 13:29:38.70 47:13:36.2 13:30:14.95 47:10:27.6 + 698.5 811.4 1093.8 1300.2 236.1 864.8 + +... Match the lists using the ccxymatch "tolerance" algorithm and a matching +... tolerance of 2.0 arcseconds. Note the negative and positive signs on the +... xmag and ymag parameters and lack of any rotation, indicating that north +... is up and east is to the left. +cl> ccxymatch m51b.coo.1 m51b.gsc m51b.mat.4 2.0 refpoints=refpts \ +lngcolumn=2 latcolumn=4 matching=tolerance lngref=13:29:52.80 \ +latref=47:11:42.9 + +... Examine the matched list. +cl> type m51b.mat.4 + +# Input: m51b.coo.1 Reference: m51b.gsc Number of tie points: 3 +# tie point: 1 ref: 26.718 -97.698 input: 698.500 811.400 +# tie point: 2 ref: -143.629 113.354 input: 1093.800 1300.200 +# tie point: 3 ref: 225.854 -75.167 input: 236.100 864.800 +# +# Initial linear transformation +# xi[tie] = 327.7137 + -0.4306799 * x[tie] + -2.0406E-4 * y[tie] +# eta[tie] = -448.0854 + 0.00103896 * x[tie] + 0.430936 * y[tie] +# dx: 327.71 dy: -448.09 xmag: 0.431 ymag: 0.431 xrot: 179.9 yrot: 0.0 +# +# Column definitions +# Column 1: Reference Ra / Longitude coordinate +# Column 2: Reference Dec / Latitude coordinate +# Column 3: Input X coordinate +# Column 4: Input Y coordinate +# Column 5: Reference line number +# Column 6: Input line number + + + 13:30:07.960 47:05:18.30 401.034 147.262 17 42 + 13:29:48.600 47:07:42.50 860.002 480.061 8 44 + 13:29:37.400 47:09:09.20 1127.791 680.033 12 46 + 13:29:55.420 47:10:05.20 698.455 811.407 14 50 + 13:30:14.950 47:10:27.60 236.088 864.817 21 52 + 13:29:29.730 47:12:04.10 1307.802 1085.564 16 60 + 13:29:38.700 47:13:36.20 1093.813 1300.189 13 63 + + +... Compute the plate solution which is identical to the solution computed +... in example 2. +cl> ccmap m51b.mat.4 ccmap.db results=STDOUT xcolumn=3 ycolumn=4 lngcolumn=1 \ +latcolumn=2 refpoint=user lngref=13:29:52.8 latref=47:11:41 interactive=no +.fi + +.ih +TIME REQUIREMENTS +.ih +BUGS +.ih +SEE ALSO +stsdas.gasp.regions,stsdas.gasp.skymap,tables.ttools.tprint,daophot.daofind,ccmap +.endhelp |