Status Report #16

Satellite and Instrument Status

A small problem has been observed during the last HRI pointings. Probably triggered by the radiation belts the HRI data readout sometimes looses synchronization. In this mode random data frames are produced with random identification headers. The groundstation interprets these data frames as originating from one of the different satellite subsystems and becomes confused. Although this happens only for a small part of time (on the order of 10 %, thus data losses are not too serious) the situation is very uncomfortable and during Real Time Checkouts could even lead to critical situations. From the data point of view a proper attitude reconstruction is inhibited during the disturbed times and automatic synchronization between planned and actual timeline is not working.

A procedure to fix the problem has been developed together with the HRI experts at SAO, this was tested over a five day test period and no data synch problems occurred during that time.

Databases:

Two new databases containing ROSAT information were recently added to the database system in the HEASARC On-line Service:

ROSTL2 - The ROSAT AO2 long-term timeline

ROSOBS - Summary of ROSAT observations

Both databases were created by Julian Osborne at Leicester Univ. from files received from MPE, and then were installed into the HEASARC system.

The ROSTL2 database contains the ROSAT AO2 long-term timeline. ROSTL2 covers the interval from 4 November 1991 to 15 April 1992. This is not the entire AO2 program -- a further long-term timeline will be produced to cover the remaining part of AO2, up to June 1992. ROSTL2 contains details of all scheduled pointed observations on a one-entry-per-slot basis, where a "slot" is an interval of constant celestial pointing with detector HTs switched on.

The ROSOBS database contains scheduling information about all ROSAT observations, from the verification phase through the AO2 phase. ROSOBS contains one entry for each ROSAT observation, and for each observation, three times are listed: the amount of observation time requested in the ROSAT proposal, the amount of time scheduled, and the amount of time actually achieved (as derived from the MPE SASS processing). The ROSOBS database is geared especially toward use by AO3 proposers who need to find out whether a particular object has been observed by ROSAT, and if so, how long the observation lasted. Please consult the ROSOBS on-line help (type the BROWSE command "dbhelp/dbname=rosobs") for details about the observation times given in ROSOBS.

All of the databases at the HEASARC can be accessed through the On-line Service. Once logged in to the captive account XRAY on NDADSA (DECnet address 15761), the user types

HEASARC> browse xxxxx

where xxxxx is the name of the database you wish to view. (Typing "browse ?" will display a list of available databases.) Users should consult the on-line help within BROWSE for more information about the individual HEASARC databases; access it by typing "dbhelp/dbname=xxxxx" where xxxxx is the database name.

A quick list of useful browse commands:
---------------------------------------

 Starting browse:
BROWSE ROSOBS     ! start browse to search the rosobs database

 Browse help:
dbhelp            ! description of the current database
help              ! general browse help

 To make a search:
sc                ! search by coordinates
sn 3c*            ! search for all names starting 3c
sp pi petre*      ! search for all pi names starting petre 

 After a search has been made:
dsam              ! display again the search results
dall 1-5          ! display all the parameters for entries 1 to 5
sif country us    ! inclusive filter on country US
sef done -100 0.1 ! exclusive filter on done time from -100 to 0.1 ksec
sort day          ! ascending sort on parameter day
sort/d done       ! descending sort on parameter done

exit              ! quit browse

From the HEASARC> prompt: mail browse.log ! mail home the results of your browse session.

There is also a new HEASARC database called X-RAY which concatenates together all the following catalogs:

A2PIC - HEAO 1 A2 Piccinotti catalog database
A3 - HEAO 1 A3 MC LASS Catalog of X-ray Sources database
EMSS - Einstein Extended Medium Sensitivity Survey database
HRICFA - Einstein High Resolution Imager (HRI) Source List database
IPC - Einstein Imaging Proportional Counter (IPC) Source List database
IPCSLEW - IPC Slew Survey Catalog database

This database gives an immediate overview of whether a source has been detected previously. This excludes EXOSAT detections, since the final EXOSAT catalog is still being cleaned and quality checked. This will be added in early 1992. In the meantime EOXSAT detections can still be checked using the CMA database.

SASS PROCESSING STATUS:

The RSDC has processed data through ROSAT day 350 (May 11, 1991) with SASS 5.3. Currently we are installing the latest release of SASS that is needed to continue processing of reduced pointed mode data (May 12 - Nov 4). This mode occurred when ROSAT developed pointing problems which forced MPE to operate the satellite in this reduced mode (one target per ROSAT day). Concurrently we are completing processing of sequences that were incomplete due to missing OBIs and missing OBI status in the processing data base. These incomplete sequences number approximately 60. To date we distributed AO1 data to 81 PIs and Verification data to 21 PIs.

Status Report #17 Status Report #15
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Curator: Michael Arida (ADNET)
HEASARC Guest Observer Facility
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This file was last modified on Tuesday, 14-Sep-1999 11:47:03 EDT