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Tips, Bugs and Troubleshooting
Some hints for successful use of GMMPS. Go directly to:
- Do not run the GMMPS in the background. If the connection to the local host fails, or other similar problems arise, then unusual errors occur in Skycat. It is safer/easier to just run the software in the foreground.
- Ignore any comments or error messages that are printed in the terminal window running the GMMPS software. This is just for de-bugging purposes.
- At the bottom of each of the Skycat windows there is a grey information icon. This displays additional information about the function of the button/window that the cursor is pointing to.
- Do not use an Object Table with an extra "." in its name. This confuses the software such that when it attempts to append the "ODF" to the file name when the mask is created.
- When the image is first displayed, the intensity levels are usually not automatically set correctly. To adjust the color scale of the image, go to "View - Cut levels" on the main menu. This will open a window in which it is possible to adjust the intensity levels of the pixels. For instance, if the intensity level is too low, then to increase the level, change the "Auto set" from 100% to 98%. This changes the fraction of pixels that are within the cut levels. Then close the pop-up window as desired. Also, one could use the "low" and "high" rectangle at the bottom of the right panel (above the "Auto Set Cut Levels" button).
- To zoom-in on the image, click on the large "Z" button to the bottom-left of the screen. Similarly, to zoom out of the image, click on the small "z" button.
- To clear the slits from the image, click the "Clear Slits" button in the pop-up window that appears when you wish to plot the slits. This is the only way to clear the slits.
- To clear the symbols from the image, go to the main menu of the Skycat window and select "Graphics - Clear". This WILL NOT, however, clear the slits from the image.
- To clear the image and all graphics, in the main menu of the Skycat window, select "File - Clear".
- By double clicking on an object's parameters in the catalog, a label will appear on the image next to that object. Towards the bottom of the catalog window, the message "labeled object xxx in image" will appear, where xxx is the object's ID number. This aids in identifying which object corresponds to the objects in the image.
- Note that it does take a couple of seconds to update the rows in the catalog window when changing column values. Thus, if multiple parameters require changing, it's easier to enter all the values in the boxes and then click "Update Row", rather than pressing "Enter" after each individual parameter value is altered.
- To force the algorithm to choose objects that are required in the mask, it is often useful to re-label lower priority objects "Ignore Object" if they are preventing higher priority objects from being selected.
- Do not manually edit the catalog file (*.cat) - always manipulate the FITS Object Table file; e.g. mask_OT.fits. Manipulating the .cat files can easily make them invalid, with the changes not being translated into the minimal ODF files. These are simply temporary files that will hopefully be removed from the GMMPS software in a future release.
- Remember that the mask making software starts to assign objects based on a specific algorithm. Care should be exercised to make sure that objects are chosen as the user wants them chosen.
- The search functionality, with columns set through "Options -- Set Search Columns..." does not work correctly.
- The slit placing algorithm does not correctly place priority 2 and 3 objects close to acquisition objects. If you have trouble getting the software to place a priority 2 or 3 object close to an acquisition object, try changing its priority to 1.
- The software does not check to see that sufficient valid acquisition objects have been chosen. A submitted mask design WILL NOT PASS THE GEMINI CHECKS if less than 2 acquisition objects are selected clear of the GMOS CCD gaps. It is possible to create a mask with only one acquisition object. However, Gemini cannot accept masks with less than 2 acquisition objects, since these are required to align the mask on the sky.
- The Mask Making Software will use the binned pixels of the pre-imaging data to determine the spacing between slits and spectra.
- After you have selected "Make Mask Files" and the window showing the
division of objects into the masks appears, you may observe that a lot of
text appears in the pop-up window that appears, similar to below (see the
writing starting from Acq Object...). This tells you that there
are too many acquisition objects selected. Go back to catalog window and
ensure that the number of acquisition objects is less than 10.
- If you find after loading the Object Table, that the symbols are not overlaid over the displayed image, it is probably because the Object Table (e.g. mask_OT.fits) does not match the image file.
- When in doubt...exit Skycat and then start the software again.
Last update April 30, 2004; Inger Jørgensen
In original form February 10, 2003; Dione Scheltus