IPAC 2MASS Working Group Meeting #70 Minutes

IPAC 2MASS Working Group Meeting #70 Minutes, 8/29/95

Attendees: T. Chester, R. Cutri, T. Evans, J. Fowler, T. Jarrett, D. KirkPatrick, G. Kopan, C. Lonsdale, H. McCallon, S. Terebey, J. White

ADDENDUM

Last week's minutes stated "the offset between KAMPhot and aperture photometry became smaller in some (but not all) scans, while the dispersion remained constant". It was subsequently determined that the offset became smaller in all scans tested.

AGENDA

New FDD Flowcharts
Galaxy Analysis
Lugosi Problems
Photometric Calibration
Flowcharting Options

DISCUSSION

New FDD Flowcharts -- J. Fowler distributed revised flowcharts for Figure 2 (2MAPPS Scan Processing) of version 3.0 of the 2MAPPS Functional Design Document (FDD). These were made in postscript format for inclusion in the 2MASS web site documentation. The new MAPCOR subsystem was included, along with the new baseline approach to position reconstruction. Several corrections were pointed out and will be incorporated.
Galaxy Analysis -- C. Lonsdale presented a brief overview of some work in progress to investigate the quality and robustness of 2MASS galaxy magnitudes. She has selected all galaxies in the May '95 Hercules data which have entries in the RC3 and has derived H band growth curves for comparison to published Tully-Fisher work.
Lugosi Problems -- R. Cutri reported that lugosi had crashed again after having already gone through a crash-and-restart cycle that day. Lugosi has been having problems lately, shutting down CPUs for unknown reasons. Several hardware fixes have been tried unsuccessfully, and work is continuing. Meanwhile, running on lugosi is discouraged, and those who must do so are requested not to write to /l6, since that is where core dumps are being directed and other debugging information is being written as solutions are sought.
Photometric Calibration -- R. Cutri reported that the point sources from all the photometric nights of the April '95 run have now been processed for photometric calibration. The extinction correction slopes now look reasonable, and the night-to-night zero-point shifts are now computable. Some discussion took place about how airmass should be handled in 2MAPPS. In the current pipeline, airmass is computed for each frame and carried in the FITS header, but the FITS frames are not read downstream where the calibration is done, and the airmass values used for all point sources in a scan are from the beginning of that scan. This isn't necessarily too coarse, but it would be fairly easy to do better in 2MAPPS, so it was decided that FREXAS would generate an airmass history file for use by CALMON and any other software that needs airmass information.
Flowcharting Options -- So far, the experiences some team members have had with the da Vinci flowchart software has been disappointing. Those who have tried this package have all found it probably unusable for our purposes. The following complaints have been made.
- There are not enough symbols. For example, there is no disk data set symbol. There is supposedly a way to create "icons" to be used as symbols, but this appears time-consuming and may not be worth the effort because of other shortcomings, and the capability may not work any better than the others. There appears to be no way to control connecting lines and arrow heads.
- It is difficult (and maybe impossible in some cases) to force the program to place the symbols vertically where one wants them. The software demands a reason to go to a lower level; for example, there may have to be a symbol above the one on a lower level.
- A kludge is necessary if one wants multi-line labels inside a symbol. There appears to be no way to enter a multi-line label via the standard dialog box other than to use special symbols like @@ to represent newline symbols, save the graph to a da Vinci script file, run that through a sed script to change all occurrences of @@ to \n, and then read the script file back into the program.
- The documentation is very poor, and the terminology is confusing (e.g., symbolized items like processing boxes and decision diamonds are called "nodes", and connecting lines are called "edges").
Since no one had a positive experience with da Vinci, we will abandon all official recommendation of it and concentrate on two alternatives. First, we will order a copy of ABC Flowcharter to be installed under MS Windows on the public 486 machine (this order has since been placed by R. Scholey); this is the program used to produce the flowcharts discussed in item (1.) above. Second, we will try the approach of taking hand-drawn flowcharts to the graphic arts section in Spalding to be converted into postscript files. J. White has some flowcharts that we will use as a test case. The postscript files have to be usable on our network printers, something that G. Kopan found in the past to be a problem with postscript files generated on the Macintosh.