Date: Thu, 13 Nov 1997 11:38:05 -0800 (PST) From: firstname.lastname@example.org To: email@example.com Cc: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org Subject: 2MASS WG Mtg #136 Minutes IPAC 2MASS Working Group Meeting #136 Minutes 11/11/97 Attendees: R. Beck, R. Cutri, T. Evans, J. Fowler, L. Fullmer, T. Jarrett, D. Kirkpatrick, G. Kopan, B. Nelson, B. Wheaton, S. Wheelock, J. White AGENDA 1.) MPCAT Delivery 2.) MAPCOR Tuning 3.) PSF Model Status 4.) Science Team Meeting 5.) Telescope/Camera/Computer Status DISCUSSION 1.) MPCAT Delivery J. Fowler reported that MPCAT 1.1 had been delivered. This version includes computation of individual observation times (i.e., correcting the scan midpoint time for each prediction's declination distance from the midpoint, using the standard scan rate of 58.9 arcsec/s), correction for proper motion that occurs during the scan, clipping asteroid major-axis error bars at a minimum of 2 arcsec, clipping 2MASS error bars at a maximum of 0.5 arcsec, and using a chi-square threshold of 16.0. The acceptance region is therefore an ellipse with major and minor axes of 8 and 4 arcsec, respectively, oriented as specified by the predictor. The area is about 100 square arcsec. It may be desirable to add code to the match-decision logic that uses the MAPCOR status information. 2.) MAPCOR Tuning T. Evans, D. Kirkpatrick, and S. Wheelock reported that MAPCOR parameter tuning had made great progress. The new parameter specifications had been delivered on 3 November; processing after that date has been using these new values. Some aspects such as bright-star processing still require further tuning activity, but the overall status of artifact flagging is one of vast improvement. 3.) PSF Model Status B. Wheaton reported that the PSF model-generating code is experiencing serious problems. Many IEEE error messages are being produced. This is especially true when running K-band data, which also experience much higher rejection rates than J or H. He is implanting IEEE exception handlers and tracing the locations where these errors occur. When the problems have been solved, it is desirable to replace the "FIND" algorithm with a routine that reads in the FREXAS detections; this should produce a speed gain sufficient to allow the code to run on several calibration scans within the pipeline for diagnostic purposes. 4.) Science Team Meeting R. Cutri reported on the highlights of last week's Science Team meeting in Boston. The following is from his Project Meeting report on this subject: Cutri, Beichman, Chester, and Mazzarella attended the 2MASS Science Team Meeting at CfA last week. High points included: 1) Receipt of the ACT catalog which uses Astrographic Catalog positions mated to Tycho positions to improve proper motions for nearly 1 million Tycho astrometric reference stars; 2) Agreement to delete at least one set of galaxy magnitudes; 3) Some useful input on parameter tuning by a few Science Team Members. Low points included several attempts to recommend design changes to pipeline, which were explicitly forbidden unless compromises to the Level 1 Requirements could be demonstrated. 5.) Telescope/Camera/Computer Status R. Cutri reported on the status of various hardware; the following is from his Project Meeting report on this subject: Mt. Hopkins operations continue. Focus mechanism failed last week and one night was lost. Problem was found to only be a faulty connection that was repaired. Shipping damage to Southern telescope will be repaired at a machine shop in La Serena. Expected delay to start of ops to be only 3-4 weeks. Analysis of southern camera Ks array reveals a large number of noisy pixels that would result in numerous 'holes' in the coverage on the sky. Recommendation at the Science Team meeting was to replace the array now that the camera is open. An email from UMASS the day after the meeting stated that the array wouldn't be replaced until further lab tests would be made. As usual, there will be an attempt to try to minimize the problem in software. The northern tape I/O computer, an Ultra 2300, was delivered 2 weeks ago. We are waiting for disks to arrive so that it can be put into operation.