next up previous contents
Next: IDL Up: Data Processing Previous: Quick Look Tools

The Lynxx Tools

The Lynxx software has its own quick analysis tools. Some processes are similar to the ST-6 tools. As previously discussed, the images can be rescaled, but if intensities are to be measured, the images should not be rescaled. The rescaling process destroys the raw data and makes intensity measurements inaccurate.

The processes for analysis are under the analyze menu. A histogram of the image can help decide if any part of the chip was over exposed. Changing the falsecolor of the image can also help in determining if a pixel is overexposed. The falsecolors display the image in a strongly varying colorbar that makes it easier to find out the counts in the pixel on examination. X and Y line scans can determine the focus of the image. When focusing the telescope, the lines scans can be a benefit to the focusing process. These procedures display the intensity along a chosen line. A zoom window is also available.

Before starting any analysis on an image, the calibration frames must be removed from the image. While these are generally carried out on the VAX using IRAF or IDL, the quick reduction methods included in the software are detailed here. The process menu contains the tools to remove the calibration frames. The flat adjust removes the bias stored in frame 5 (see figure 1 for frame positions). The flat stored in frame 6 is used to correct the image. The therm adjust process removes the dark current. This will correct for the dark in frame 4 in addition to the bias and the flat. When executing either of these procedures, the operator should place the correct flat frame and correct dark frame in the buffers.

The remainder of the commands can be used for determining the intensity of the objects in the frame. Meas intensity is the command that will measure the intensity of the object in a square region around a star. The size of the square region can be changed with the command square size. A suggested size for the aperture is one that encloses all of the star and has a small section of sky around the star. After the star is measured, the background should also be removed. To do this, a square of the same size should be placed on a region that represents the background around the star. The difference between the two values is a more accurate representation of the relative intensity. An appendix to the Lynxx manual describes photometry with the Lynxx software.

A separate software package is The Personal Observatory. This is a package that allows the ST-6 and the filterwheel to be run simultaneously. Unfortunately, the track and accumulate mode will not work if the ST-6 is run by Personal Observatory. It is advised to use the SBIG software.

Although the camera cannot be operated by the Personal Observatory, it can be used for data reduction. Again, there are better processes in IRAF and IDL. This is a description for a quick look at the data. There are procedures for tricoloring images by using three images in different bands, and some photometry can be done in this software. The Adobe Photoshop can be used for color images also.



next up previous contents
Next: IDL Up: Data Processing Previous: Quick Look Tools



Scott J. Wolk
Mon Nov 25 15:41:03 EST 1996