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


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.


  1. New FDD Flowcharts
  2. Galaxy Analysis
  3. Lugosi Problems
  4. Photometric Calibration
  5. Flowcharting Options


  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

    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.