INTEGRAL LOGO INTEGRAL Commissioning & PV phase results

After the completion of the Cygnus off 9.65 observation the Performance and Verification (PV) phase ended on December 29 as planned. In summary the PV operation went extremly smooth due to the very good collaboration between all involved parties. INTEGRAL is now in Nominal Mission Phase (starting in revolution 25) with the execution of the Observing Programme.

Revolution 25 (2002/12/26 - 2002/12/29)
The observations of revolution 25 were executed as planned. The revolution started with the continuation of the empty field observation, followed by the OMC flatfield observation and the Test GPS. The execution of the test GPS was closely followed by the instrument teams and at ISDC. At the begin of the revolution the bad PICSIT pixel already observed and removed in revolution 24 re-appeared. The bad pixel was killed again and this time also saved in the IBIS context preventing its re-occurence in future.

Revolution 24 (2002/12/23 - 2002/12/26)
Observations of revolution 24 were executed according to plan pointing for the entire revoution to the Empty Field 2. From December 24 at 0900Z PICSIT was operated in PPM mode for 90ksec at high TM rate, while SPI was operated at the minimum TM rate. After some monitoring a PICSIT bad pixel was killed in the afternoon of December 24. In the morning of December 25 ISDC did not receive TM from MOC. The remainder of the revolution the satellite stayed at the same pointing and operation went smooth. A burst was detected in the SPI ACS data on December 26 at 14:35.

Revolution 23 (2002/12/20 - 2002/12/23)
Revolution 23 was executed as planned. Rather smooth revolution. GRB021223 (reported in the GCN GRB observation report #1778) was seen by SPI ACS. The solar flare on Dec 21 at 11h10 UTC was seen by ACS and JEM-X.

Revolution 22 (2002/12/18 - 2002/12/20)
The observations of this revolution were executed as planned. The solar activity was high during this revolution and kept the ISDC shift team busy to distinguish between solar flares and GRBs. A burst in the partially coded FOV was detected and localized on December 19 at 7:33 UTC and reported in a GCN (#1766). The initial position was refined within 6 hours (GCN #1768) and the position uncertainty reduced donwn to 4 arcminutes. The timelines (input for automated commanding) of the remaining PV activities up to December 30 were generated by ISOC and MOC. The instrument teams prepared the required input for the execution of the dedicated IBIS background field observation on December 24. During this observation PICSIT is operated in photon-photon mode for a period of 90ksec with a very high telemetry allocation (85% of the total available telemetry). The accumulated data will be used to calculate improved PICSIT background maps.

Revolution 21 (2002/12/15 - 2002/12/18)
The revolution was excuted with the observations as planned. The first revolution with a new dither dwell time of 2200 sec.
SPI had a high TM allocation for a duration of 90ksec in total,  which allowed to downlink all data in photon-photon mode (in normal operation single events are downlinked as onboard accumulated spectra).
On December 16 at 07:38Z IREM suffered a Single Event Upset and indicated a failed condition. IBIS, JEM-X and OMC reacted correctly and went into their Safe Mode. SPI continued data accumulation at the high TM rate, as the IREM input to SPI was not enabled. IREM was brought back into its normal operation mode and after some time of monitoring the onboard IREM broadcasting was enabled again.

First light data were presented at ESA HQ to the press (18 Dec).

Revolution 20 (2002/12/12 - 2002/12/15)
A swift replanning of revolution 25 was required to consider the unavailability of the Goldstone station due to a launch support (from December 13 18:27 to December 14 at 02:15). The replanning led to the exposure durations as indicated in the planned section. On Saturday December 14 at 16:21Z an AOCS command failed verification on the ground before uplink. As a consequence the automatic timeline for the AOCS system was disabled until the problem (on the ground) was understood. The timeline was rejoint at 21:31Z. No slews were performed in between and 11 dither pointings were missed.

Revolution 19 (2002/12/09 - 2002/12/12)
Revolution 19 was executed as planned.  The timeline had to be interrupted in two occasions. Once when during a ground station handover the ground station only become available after a short delay and once when the guide star was not found in the inital mapping of the star tracker. Five dithering points were lost because of this. On December 10 the OMC remote commanding through IBAS was tested. After having fixed an initial inconsistency between the systems  the remote commanding was validated and the proper functioning was confirmed.

Revolution 18 (2002/12/06 - 2002/12/09)
Revolution 18 was executed as planned. For the first time the entire revolution was executed based on ISOC planning input. Revolution 18 was the last PV revolution consisting entirely of staring observations. From now on until December 24 dithering observations will be executed. The revolutions up to 24 contain observations mainly for SPI calibration

Some manual commanding at begin of revolution 18 were required to change  instrument parameter settings based on instrument team input. At the ground station handover a recovery of the timeline was required after a delay in the ground station readiness.

Revolution 17 (2002/12/03 - 2002/12/06)
JEM-X commissioning activities were performed as planned.. The JEM-X was pointed 2, 3, 4, 5 and 6 degree off from Cygnus X-1 to calibrate the detector off-axis response and to investigate a possible cross talk between the two JEM-X cameras. In addition, JEM-X was configured in various primary and secondary telemetry formats to validate these configurations. In the remainder of the revolution the IBIS Cygnus X-1 on-axis staring calibration observation was continued.

Revolution 16 (2002/11/30 - 2002/12/03)
During the night from 2002/12/1 to 2002/12/2, 4 hours of data were lost during the Goldstone passage. On 2002/12/03 a payload comissioning status meeting took place at ESOC with participation from all instrument teams. The status of instrument commissioning was reviewed in preparation for the Mission Commissioning Readiness Review scheduled for Dec 12 & 13.
PV observations executed as planned, staring on Cygnus X-1. First revolution with reduced JEM-X TM allocation. In the middle of the revolution the JEM-X configurations were swapped between JEM-X1 and JEM-X2. Some ISGRI modules continue to show high count rates.

Revolution 15 (2002/11/27 - 2002/11/30)
Executed as planned, a long Cygnus staring observation. JEM-X is doing tests with the discriminator setting to lower the energy threshold. JEM-X configuration for remainder of PV revolutions  was redefined in view of the recently agreed TM allocation for JEM-X.

SPI did tests on the spectra accumulation duration. Spectra were accumulated with a duration of 1h and  2h. The maximum possible duration was calculated as 9h.

Revolution 14 (2002/11/24 - 2002/11/27)
Observations executed as planned with a 100ksec pointing on the empty field 1 and a subsequent staring observation  on Cygnus X-1 for the rest of the revolution.

PICSIT was operated in photon-photon mode during the Cygnus observation. In this period a GRB burst was detected. A GCN was issued. ISGRI registered the burst as well. At the time of the burst SPI was not operated in photon mode and was only acquiring spectra, GRB seen in SPI-ACS.

OMC full FOV image succesfully acquired. The ISWT took place and it was decided  that INTEGRAL will begin the operational phase operating with only one JEM-x unit at a time.

Revolution 13 (2002/11/21 - 2002/11/24)
Empty field 1 09:59:21.79,-00:58:55.21 full revolution,  staring SPI PV activities:
SPI continues to lose packets per cycle. PSD library had to be uploaded twice because initially the  least and most significant bits were swapped.

Due to Goldstone outage and re-loading of PSD library only 8h of data are available for the PSD table verification (instead of 24h). Only a limited validation of the PSD library is possible.

The 10 ksec science observation on the empty field was not executed, as an  AOCS calibration was performed instead.
OMC was left in science mode during the AOCS calibration which led to a generation of 8h not meaningful data.

Revolution 12 (2002/11/18 - 2002/11/21)

Revolution 11 (2002/11/15 - 2002/11/18)
The routine operations, such as slews or the activities related to the Perigee Passage have been performed - for the first time - from the automatic timeline using scheduling input from ISOC, while most of the calibration activities were performed using manual commands.
Automatic timeline will be the baseline for the routine missions operations.

The  service  module is nominal.  Wheel biasing operations were conducted on the 16th  at 19:26 UTC. RMU calibrations were conducted on the 16th at 08:51 and on the 17th at 03:51 and 20:29 UTC.

First astronomical target (Cyg X-1) was observed and IBIS/ISGRI and SPI produce first images.

SPI  was  in  the  nominal science mode during this reporting period. Tests were conducted for SPI influence of ACS thresholds on the background.

IBIS Instrument tuning is still on going.

JEM-X is in data taking mode and operations are being conducted in accordance with the automatic timeline. After the identification of the problems with the anodes the JEM-X 1 has been operated at lower voltages (80 V below nominal). This reduced the gain by a factor of 2.6. Apart from this the instrument is performing well. For safety reasons the instruments are currently put in Safe Mode 90 minutes before the altitude of 60.000 Km is reached.

The OMC is operating nominally. One OMC image acquisition has been performed each day with a minimum duration of 45 minutes. Outside these periods OMC was in Stand-by mode. On  OMC  the  PV  phase  Dark Current and Flat Filed Calibration activities
that started at 12:50:00 UTc on the 15th of November continued until 10:00 UTC on the 16th.

A slew from the OMC calibration target to CYGNUS-X1 was conducted on the 16th between 19:51Z to 20:18Z.

The IREM unit is nominal. No special activities were conducted.

Revolution 10 (2002/11/12 - 2002/11/15)

Revolution 9 (2002/11/09 - 2002/11/12)

On the 9th of November a worst case slew manoeuvre was conducted. The purpose of  this test was to command a very long slew, approximately 163 degrees, with the  wheels close to their stability constraints while observing the resulting slew errors. The test required approximately 7 hours to complete and included a slew back to the science attitude. The slew ended with an error of about 5020 arcsec, which means an error of 0.87 % with respect to the slew length. This is better than the specification. However, the slew back to the science pointing, which was shorter and at a bit higher altitude caused a bigger error. Hence, it is possible that shorter slews might have relatively larger errors. This is due to the fact that the larger slews have more stringent conditions.

SPI was in the nominal science mode during this reporting period. Performance tests and fine-tuning of subassemblies were conducted. No anomalies were detected.

IBIS was working in normal science mode during this reporting period. Throughout the weekend parameter optimization of the instrument was performed. No anomalies were detected. On the 12th of November it is planned to perform a calibration of  the ISGRI.

Both JEM-X units were configured to safe mode on November 7th. Tests were successfully conducted with JEM-X1 on the 11th with a lower High Voltage value. The origin for the observed degradation of some anode strips of the microstrip detectors in both units is under investigation.

The OMC was in stand-by mode during this reporting period.

IREM is functioning well but it was observed during this weekend that it was down-loading data 8 hours in the past. On the 12th of November it is planned to toggle the operational mode from "INTEGRAL" to "Standard" and back again in order to
correct this problem.

Revolution 8 (2002/11/06 - 2002/11/09)

Revolution 7 (2002/11/03 - 2002/11/06)

Revolution 6 (2002/10/31 - 2002/11/03)

Revolution 5 (2002/10/28 - 2002/10/31)

Revolution 4 (2002/10/25 - 2002/10/28)

Revolution 3 (2002/10/22 - 2002/10/25)

Revolution 2 (2002/10/20 - 2002/10/22)

Revolution 1 (2002/10/17 - 2002/10/20, times in UTC)