+This tarball contains a +collection of data from 6 Megacam standard star image obtained in +September, 2003. There are two sets of three images, taken two weeks +apart (03 Sep and 21 Sep). In each set, there is one each of g', r', +and i' images, all short exposures of 3.0 seconds. This dataset makes +a useful demonstration of the DVO system. + +
+The tarball contains 6 directories, one for each image. The images +have been processed with the Elixir system and the photflat-corrected +flat-field images for each filter, though no fringe correction has +been applied. Sextractor has been run on all of the images, and only +the sextractor-derived photometry is available in the tarballs. No +image pixel data is kept. The directories are named after the +exposure odometer numbers, eg 718688o. + +
+Within each directory, the data is separated into a number of files +for each of the 36 detector, with names created by appending the chip +number to the odometer number of the image, eg 718688o00. For each +detector, the directory contains: + +
+The raw sextrator output consists of a fixed-format ASCII table with +columns defined by the Elixir processing system. The Elixir cmp +format merges the sextractor photometry table with the image header to +form a pseudo-FITS table. The smf format contains essentially the +same information as the smp format, but the table portion of the data +is written as a FITS table in the first extension, with appropriate +table description in the table header unit. The primary header of +this file consists of the original image header, with the value of +NAXIS set to 0. This has the effect of making the file a valid FITS +file, while keeping the information of NAXIS1 and NAXIS2 (the original +image dimensions), while eliminated the data taken by the image array. + +
+Both the .smp and .smf files include the astrometric solution in the +form of WCS header entries. In the case of these files, the +astrometry requires a linear solution across the chip. The linear +solution provides a robust solution, but results in systematic errors +which are substantial, roughly 0.5-1.0 arcsec, due to the optical +system distortion. A better solution can be obtained by fitting +higher order polynomials. We use a two-layer solution, with one set +of third-order polynomials to represent the warping of each detector, +and a second third-order polynomial to represent the telescope optical +distortion. The .xmf files represent the same data as the .smf files, +also in the FITS table format, but with the two-layer mosaic +astrometric solutions in their headers. In addition, these files +require the single .phu file which represents the full-mosaic PHU and +contains the top-level telescope distortion solution. + +It is possible to add any of these data to the DVO database using the +addstar command. To add any of the .smp files, simply use the +command: + +
+addstar filename.smp ++ +To add any of the .smf files, it is necessary to specify the +-fits flag: + +
+addstar -fits filename.smf ++ +To add any of the .xmf files, it is necessary to specify the +-fits flag and to identify the mosaic astrometry file: + +
+addstar -mosaic root.phu -fits filename.smf +Index: /trunk/Ohana/doc/www/html/DVO/sequence.idx =================================================================== --- /trunk/Ohana/doc/www/html/DVO/sequence.idx (revision 4834) +++ /trunk/Ohana/doc/www/html/DVO/sequence.idx (revision 4835) @@ -1,4 +1,6 @@ DVO-shell.htm commands.htm +example.htm +navigate.htm addstar.htm delstar.htm Index: /trunk/Ohana/doc/www/html/download.htm =================================================================== --- /trunk/Ohana/doc/www/html/download.htm (revision 4834) +++ /trunk/Ohana/doc/www/html/download.htm (revision 4835) @@ -29,6 +29,6 @@ @@ -40,8 +40,8 @@ @@ -62,5 +62,5 @@ @@ -72,5 +72,5 @@ @@ -82,5 +82,5 @@ @@ -91,7 +91,7 @@