NUMBER 67
DATE: 03/06/89
Sector Processing Center (SPC):
During January, AES, JMA, CSU, ESA and JMA collectively processed greater than 79% of A data into B1/B2 data.
Normal operations were reported by NOA and JMA.
ESA reported that a further decontamination exercise on METEOSAT-3 was carried out from 0900 GMT on 31 January to 0830 2 February, making the IR and WV channel calibrations unreliable for this time period.
AES reported the beginning of operations with their new front-end data ingest system. This system ingests the full Mode AAA data stream and extracts the required Mode A data in real time. Missing data at the beginning of the month were caused by the combination of multiple power failures and some problems with the new ingest system. These earlier data may have some misaligned grid bits (representing latitude-longitudes and coastlines in the image) and some corrupted header information. This new system should significantly increase the reliability of data collection. Revision of the software that produces both the B1 and B2 data tapes has been completed to make AES data consistent in format with that of other SPC's; re-processing of the B1 data will be carried out jointly by AES and the ICA over the next several months. The current B2 delivery had the corrected format.
CSU reported that excessive satellite "wobble" made navigation of GOES-6 difficult, causing the loss of some
data. NOAA permanently terminated GOES-6 VISSR/VAS operations on 21 January at 1845 GMT after
failure of the last encoder lamp. The images for 0015, 0915, 1215, 1515, and 1815 were transmitted as partial
images that start randomly on scanlines 51 through 151 and end on 1451 through 1671.
Special Area Processing Center (SAPC):
No reports were received.
Satellite Calibration Center (SCC):
No report received.
Global Processing Center (GPC):
The GPC continued to receive B2 data and correlative data in a routine manner.
Re-processing of all NOAA-7 B3 data to correct the small IR count error has been completed (July 83 through February 85); all of the re-processed data for NOAA-7 have been delivered to the ICA. Re-processing of NOAA-9 B3 from January 85 has started and is complete through March 85.
Production of B3 data from GMS-3 has resumed, employing the new IR calibation data set supplied by JMA.
Delivery of the re-calibrated geostationary satellite B3 data (GMS, METEOSAT, GOES) has been completed through June 84. Inspection of data for the second half of 84 and for 85 is underway.
Special pixel-level data for the FIRE Cirrus Intensive Field Observation period (October/November 86) from GOES-6 have been completed and delivered to the FIRE archives. Some additional NOAA-9 data sets are being produced for the SRB project algorithm pilot study.
C1 data for March and April 84 have been completed and sent to the ICA. Production of May and June 84 C1 data has started. After completion of the first year of data, we plan to take a break to process some more special data sets for the field experiments and to repair some of the minor errors in the C1 data. We will completely replace the C1 data set by June of this year and start delivery of C2. A newly completed version of the C2 production software is being tested.
Re-processing of selected C1 data sets, affected by the sea ice reflectance error, is underway; the
METEOSAT and GMS data for September 83 were completed this month.
ISCCP Central Archive (ICA):
The ICA continued to receive B1 data from NOA, AES, CSU, ESA, and JMA and B3 and C data from the GPC
in a routine manner.
In addition to your own comments about the contents of the C2 data; please send to the GPC any suggestions for other people to contact, especially those interested in climate diagnosis studies. A new proposal for C2 contents is being prepared for mailing later this month.
A paper describing the AVHRR visible (and IR channel) calibration monitoring system has been completed and will be submitted to the International Journal of Rem_te Sensing as soon as the graphics are completed. Preprints will be distributed to the WGDM mailing list later this month.
A double-valued; hence substitution of a brighter surface reflectance in the correct analysis will not alter cloud optical thickness values that much (it is hard to predict this effect exactly since it depends sensitively on illumination and viewing geometry).
We have begun a re-processing of all data affected by the error (only regions covered by sea ice that is illuminated by sunlight with solar zenith angles < 80 degrees are affected). Since the magnitude of the error and the fraction of the globe affected are small, we are continuing the scheduled production (the error was corrected in the most recently delivered data for December 83 and February 84) until we complete the first year of C1 data; however, we are doing some of the re-processing in parallel (we have completed the METEOSAT data for August 83). Thus, we expect to replace all of the affected C1 data by May 89. In fact, we are carrying out another detailed inspection of the C1 data and will take ts for FIRE, ICE and the Surface Radiation Budget project.