Known Bugs in the UVOT software
See also: UVOT Digest for discussion of open issues with UVOT software.
Swift users are encouraged to submit bug reports to swifthelp via our Feedback form, so they can be tracked and added to this list.
Priority code used in list, below: Yellow (3) = minor, Orange (2) = important, Red (1) = urgent. Green (:)) = fixed and will be available in the next build.
| Date | Tool | Priority | Symptom |
|---|---|---|---|
| 2007-09-04 | uvotexpmap | 2 | Current version does not identify exposure time variations near the edges due to the shift and add algorithm used to correct for attitude changes. Work is in progress to implement this. |
| 2007-05-24 | uvotimsum | 2 | Uvotimsum will add two exposures that have different frame times. However, photometry on the summed image will return incorrect results because coincidence corrections depend on the data having one frame time. The temporary solution is not to use such coadded images for photometry. |
| 2007-04-26 | uvotproduct | 2 | In revision. |
| 2007-04-26 | uvotapercorr | 2 | Currently uses B PSF for White filter. (Tool is in development). |
| 2007-09-04 | uvotmaghist | 3 | The time columns (TIME and MET) in the current (6.3.1) release were inadvertently changed to report the start rather than the mid-time of the exposure. They will again report the mid-time in the next (full) release. Note that the TIMEPIXR keyword is set to 0.0 when start times are used, and to 0.5 when mid-times are used. |
| 2007-04-26 | uvotdetect | 3 | Current version gives unreliable results when given an exposure map. We recommend not using an exposure map when working with unsummed images. When working with summed images, we recommend setting "expopt=ALPHA". |
| 2007-04-26 | uvotimsum | 3 | Current version doesn't include the image binning keywords - defaults to coarsest binning of the input images, but allows arbitrary binning. |
| 2007-04-26 | uvotevgrism | 3 | This tool operates on grism exposures taken in event mode. Due to the very low number of exposures taken in this mode/filter combination, this tool is not well tested. |
| 2007-04-26 | uvotexpcorr | 3 | The functionality of this tool has been mostly superceded by routines in uvot2fits to identify and correct problems with onboard shift and add that result in lower exposure time. |
| 2007-04-26 | uvotflatfield | 3 | Not well tested. The current UVOT flat field is a unit matrix, so applying this flat field to the data does not adjust count rates. |
| 2007-04-26 | uvotmag | :) | Depricated; replaced by uvotflux. Users who use uvotsource or uvotmaghist to do photometry have the option of setting method=CURVEOFGROWTH, which will correct for aperture size. Also, see the task uvotapercorr to obtain corrections from one aperture to the standard aperture. |
| 2007-07-06 | uvotsource | :) |
The Swift/UVOT tool uvotsource, which derives instrumental
source magitudes from an image, contained a bug when
calculating the coincidence loss factor using the new option "method
=CURVEOFGROWTH". This bug has been fixed in the current release. (6.3.1)
|
| 2007-04-26 | uvotevtlc | :) | Previous version only took simple region files. Fixed in current release - now accepts arbitrary region files. (v. 6.3.1) |
| 2007-04-26 | uvotexpmap | :) | Previous version produced exposure maps with problems near edges and in the vicinity of bad pixels. A new parameter ("maskfile") in the current version can be used to create a mask for the output exposure map. The mask can be applied to the exposure map and sky image to trim off the questionable pixels at the edges. (v. 6.3.1) |
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