CASB Report April, 2001

Highlights for Division Meeting

· Completed the export of over 99.5% of database regions into the GSC2.2 catalog.

· Delivered the Instrument Scientist’s version of the Bright Object Tool.

Community Affairs and Communications

· Loomis participated in a live web cast as part of the San Francisco Exploratorium multimedia "Origins" exhibit featuring the Hubble Space Telescope. A tape was shown of the plate vault and scanning machines. He was interviewed and provided narration for the plate vault segment as well as answering questions.

· Morrison attended Division on Dynamical Astronomy of the AAS meeting in Houston (April 23- 25) and presented a talk on the GSC-II catalog.

· McLean is away on a GSPC-II observing run at La Palma.

· Supported tours for Bring Your Children Day.

· Mario Lattanzi visited CASB, April 17–27, to start on a GSC-II document (including a description and evaluation of GSC 2.2) suitable for both the new web pages and as an advanced draft of a paper for eventual submission to a major journal (probably AJ). A detailed outline was put together, which has already evolved into a draft article. After McLean reviews this draft, it will be circulated internally. Thanks to Laidler, Morrison, McLean and Smart for providing Lattanzi with much of the text needed for the editing task.

Project Management and Technical Infrastructure

· McLean and Greene continued supporting SDSS planning activities.

· Wil O'Mullane is visiting CASB and working on ShowSky, which will be used for GSC-II/DSS-II access.

MISSION SUPPORT

HST Operations

· Reviewed four Guide Star Problem Reports (GSPRs) and one HOPR this period. Three GSPRs were fine lock failures; another was a search failure due to a misclassified plate flaw. The HOPR documented acquisition problems due to the relatively high proper motion of the GS. Filed a Bad GS Alert for each of the GSs.

· Continued work with Jesse Doggett on the Bright Object portion of the Astronomer's Proposal Tool and the Visual Target Tuner. At the end of March, delivered an initial version of the Bright Object Tool to the Instrument Scientists, to enable them to check Phase II proposals for health and safety issues. (Previously released a public version of the tool for STIS MAMA imaging.)

· The next goal is to have another public release of Bright Object Tool around the beginning of June, which will include the use of the new GSC 2.2 plus minor bug fixes that are found.

· Provided support for production of STIS moving-target finder charts and data for Venus and Mars observations.

NGST Development Studies

·

DIGITIZED SKY SURVEY

Plate Scanning

· Scanned POSS-I O plates until the latest shipment of UKST-IR plates was logged in.

· Scanned only a few UKST-IR plates before both microdensitometers were taken out of production.

GAMMA Microdensitometer Systems

· No maintenance performed this period due to allocation of resources to complete GSC2.2.

· GAMMA1 needs preventive maintenance.

· GAMMA2 remains out of production due to a problem that is causing a feedback to the X-servo causing very unstable table motion.

Data Compression/CD Production

· Continued compressing scans of the POSSII-N survey.

· Completed compressing all the UKST-IR plates that have been scanned so far.

· Modified compression pipeline to allow compression of POSSI-O and AAO-SR (short-red) plate scans. Started compressing the latter.

Archive Maintenance

· Completed the archive of all AAO-SR plates to MOD.

· Continued low-level rationalization of MOD archive.

GSC-II

Plate Processing and COMPASS Database

· Completed the export of 32,633 database regions, over 99.5% of the total, into the GSC2.2 export catalog. Most of the remaining 135 regions were excluded due to plate matching problems. This export catalog is composed of two bandpasses with all sky coverage.

· Reduced the number of unmatched southern plates to six. Several of these are very complicated areas of the sky for which no short exposure plate exists.

· Identified and corrected a number of problem plates through analysis of statistics associated with the export. Corrected over 300 regions so far and now actively cleaning up all known errors. The cleanup time frame is estimated to be on the order of a few weeks and should result in the addition of many additional catalog entries.

· The current counts of objects in the GSC-II database are 423,597,861 in the north and 564,804,940 in the south, for a total of 998,402,801. Currently 396,423,219 of these objects are in the export catalog, which has faint magnitude restrictions.

· Resumed processing POSSII-N plates.

· Also processed 15 plates of the UKST-IR survey, which lacks an astrometric mask. Constructing a mask from the plates just processed. When the mask is available, will recalibrate these plates and then continue processing the rest of the UKST-IR plates.

CALIBRATIONS: General

· Performed statistical analyses and spot-checking of the exported catalog regions to identify problem areas and to verify expected performance.

CALIBRATIONS: Astrometry

· Worked on quantifying the magnitude term in GSC II positions by comparing the GSC 2.1 catalog with the 2MASS, SPM and NPM catalogs.

CALIBRATIONS: Classification

· Completed a set of cross-validation experiments to determine the optimum size of the feature set for classification. Experiments were conducted on both a subset of the best features, selected via correlation analysis and analysis of the current decision trees, and on the full set of features.

· Results indicate that the OC1 decision tree is quite robust even with the full set of 30 features, as there is no indication of confusion reducing the accuracy at higher feature set sizes. The size of the feature set can probably be reduced by 10-15 features without impacting accuracy, which would improve run-time performance. These experiments also provide an additional independent assessment of which are the most significant features.

· Began analysis of the multi-plate voting used for classification in the GSC2.2 export catalog. Preliminary comparisons to a subset of the 2MASS PSC indicate that unanimity in voting is a good indication of classification quality. Comparisons to a color-selected galaxy subset of the FIRST catalog indicate very good results: 91% completeness for a sample of 7249 galaxies in a magnitude range of 10 < F < 17.5.

CALIBRATIONS: Photometry (GSPC-II and DSS-I and -II)

· Reduced observations from the latest CTIO observing run.

· Observing run using JKT at La Palma is in progress (Apr 26 – May 02)

GSC-II Science

· F. Guglielmetti is working on production of a new Planetary Nebula catalog with improved coordinates from GSC2.1. She is collaborating with Florian Kerber, Roberto Mignani, and Andreas Wicenec (ESO). The new catalog is nearly complete except for some areas that are expected to be covered by GSC2.2.

· D. Carollo has identified a carbon dwarf star among the halo white dwarf candidates. This is a significant discovery!

Appendix – CASB Statistical Summary

SCANNING

Survey		Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-II J	897		902	0	902	100	S4	1
POSS-II F	897		910	0	910	100	S4	1
POSS-II N	897		880	0	880	98	S4	1
AAO-SES	606		614	0	614	100	S4	1
PPARC-ER	288		288	0	288	100		1
AAO-SR	118		118	0	118	100	S2	-
UKST-SR	112		50	0	50	45	S5	3
UKST-IR	894		652	6	658	74		2
SERC-J/EJ	447		443	0	443	99	S1	2
POSS-I E	106		106	0	106	100	S3	3
POSS-I O	936		301	6	307	33		3
Rescans			34	0	34

• S1. Low priority program to rescan crowded fields (|b|<30) originally done with 25 mu scans. The total number of S scans includes the 2 for the LMC and SMC plus 4 others with |b|>30 performed for research or STIS BOP support. Another 30 plates have been added to replace those that were repaired before inclusion in DSS-I.
• S2. This survey is an on-going low level-of-effort collaboration between the STScI and the AAO. About 25-50 plates have been added in each of the past few years.
• S3. Low priority scans of the POSS-I -24 deg and -30 deg zones.
• S4. Includes recent scans of better grade plates.
• S5. Low priority scans of the moderately short exposure R plates from the SERC I/SR Atlas of the Milky Way.

COMPRESSION

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-II J	897	895	0	897	100		2
POSS-II F	897	897	0	897	100		1
POSS-II N	897	541	36	577	64		3
AAO SES	606	606	0	606	100		1
PPARC ER	288	288	0	288	100		1
UKST-IR	894	570	88	658	74		3

MO DISK ARCHIVING

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-II J	897	902	0	902	100		4
POSS-II F	897	900	0	900	100		3
POSS-II N	897	780	43	823	92		4
AAO-SES	606	613	0	613	100		3
PPARC-ER	288	288	0	288	100		3
AAO-SR	109	73	43	116	100		4
UKST-IR	894	653	5	658	74		5
SERC-J/EJ	894	892	0	892	100
SERC-J/REPAIR	48	48	0	48	100
SERC-J/15mu	449	449	0	449	100		5
POSS-I E	933	928	0	928	99		2
POSS-I REPAIR	198	198	0	198	100		2
POSS-QV	613	613	0	613	100		-
SERC-QV	94	94	0	94	100		-
GPO/BB	88	88	0	88	100		-

GSC-II PLATE PROCESSING

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-I E	936	931	0	931	99		3
POSS-QV	613	2	0	2	0		3
POSS-II J	897	897	0	897	100		1
POSS-II F	897	897	0	897	100		1
POSS-II N	897	44	38	82	9		4
SERC-J/EJ	894	829	0	829	93		1
South-F	894	894	0	894	100		1
UKST-IR	894	0	15	15	2		4
South-SR	116	110	6	116	100		2
South-QV	94	94	0	94	100		2

GSC-II COMPASS DATABASE LOAD (no.objects = 998,402,801)

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-I E	936	23	0	23	2		3
POSS-QV	613	2	0	2	0		3
POSS-II J	897	897	0	897	100		1
POSS-II F	897	899	0	899	100		1
POSS-II N	897	27	0	27	3		4
SERC-J	894	708	1	709	79		1
South-F	894	742	0	742	83		1
UKST-IR	894	2	0	2	0		4
South-SR	116	116	0	116	100		2
South-QV	94	90	0	90	96		2

GSC-II Dataset for V2.2.n delivery (1791 Fields, 3438 plates) (P1)

Item	Count	% done	Notes
Plates available	3438	100
Plates processed	3438	100
DB Load	3438	100

• P1. Defined as all 897 POSS-II fields with 1794 plates, plus the 894 southern

Fields, minus the 72 southern equatorial fields, with 1644 plates.

GSPC-II OBSERVATIONS

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-I	584	559	2	561	96	P1	1
POSS-II	314	169	2	171	54		1
SERC	894	868	16	884	99		1

GSPC-II REDUCTIONS

Survey	Goal	Previous Month	Current Month	Current Total	% done	Notes	Priority
POSS-I	584	561	2	563	96	P1	1
POSS-II	314	171	4	175	56		1
SERC	894	884	17	901	100		1

• P1. The current totals have been revised from earlier ones.