NUMBER 49

DATE: 09/03/87

Sector Processing Center (SPC):

During July, ESA and JMA collectively processed greater than 98% of A data into B1 and/or B2 data. AES processed 58% of A data in July. No processing matix was sent by NOA.

Normal operations were reported by ESA, JMA, CSU and NOA.

The March, April, May and June processing matrices were received from NOA. NOA also delivered the last two months of NOAA-8 B2 data to the GPC, eliminating the backlog. At the request of the GPC, NOA will re-process the first month of NOAA-8 data, which had been produced with a much earlier version of the production software.

Data and processing reports were received from CSU for March, April, May and June. Delivery of these GOES-6 B1 and B2 data had been delayed by the change in data transmission format to the AAA format at 1815 GMT on 25 March 1987. Adjusting to the new transmission format caused the loss of 22% of the images in the last week of March. Collection rates were much better after that, increasing from 88% in April and 85% in May to over 90% in June. Since the new AAA format transmits IR data as 10 bit counts representing radiances, in place of the A format 8 bit count representing brightness temperature, CSU is currently translating the IR data to simulate the old coding. However, once a new coding is agreed to amongst CSU, AES and the GPC, the new GOES IR data will be linear in radiance like the other satellites. CSU also reported that GOES-6 was moved back to its original "WEST" position during April; it is now located at 135W. In June a scan motion "hang-up" created more than 50 partial images during the last week of the month.

AES reported improved processing performance, but there were still significant disruptions of operations in July. The main problem now is the "front-end" receiving system; a planned replacement system is scheduled for installation by the end of the year. Some B2 data were inadvertantly lost, but they will be re-generated from the B1 data.

Special Area Processing Center (SAPC):

No reports were received.

Satellite Calibration Center (SCC):

No report was received.

Global Processing Center (GPC):

The GPC continued to receive B1 and/or B2 data from JMA, ESA, CSU, AES and NOA and correlative data from NOAA/NESDIS in a routine manner.

The repeat of the NOAA-7 monitor results with the corrected code has been completed through August 1984, leaving only 5 months to process. As expected, the amplitude of the apparent seasonal cycle of the calibration has been reduced by about a factor of 2; however, no changes in previously reported results are implied.

Two months of NOAA-8 B2 data have been processed into B3 for intercomparison of calibrations with NOAA-7. The first month, October 1983, was found to be unusable because of an apparent error in the processing software that constructed images from many different segments from different days. The GPC has requested that NOAA re-process this data with their newest software. The data from November 1983, which had been produced with the newest software, had no errors. Normalization of the NOAA-8 VIS channel data is complete, though a few additional tests are underway that will be finished next week. The inferred relation between scaled radiances is

The QC backlog for GOES-6 data from July 1983 through July 1984 has been eliminated; the first two steps of the QC inspection having been completed. Final inspection of the suspicious images for the entire 19 month data set will begin next week. QC production for GOES-5 B3 data from July 1983 through July 1984 has started and should be completed within two weeks. Completion of the QC inspection for all of the GOES data should take about two to three months.

Although delivery of 4 months of GOES-6 B3 data was reported last month, discovery of an error in the Volume ID file delayed delivery until later in August. This problem has been corrected. Subsequent deliveries of GOES-6 data are dependent on the provision of BC data by the SCC; upon receipt of each BC data set, the corresponding three months of B3 data can be processed in a few days. GOES-6 B3 data without BC is available for November 1983 through January 1985.

Remapping of the sea ice data for 1983 and 1984 is underway and should be completed within a week. A merging procedure has been designed so that the sea ice data from the northern and southern hemispheres, as well as the snow data, which cover different date ranges, can be combined into a single data set which preserves the original information. Once documentation of the snow data format is received from NOAA, remapping and merging of the snow data with the sea ice data will begin.

The first part of the TOVS processing code has been completed. This processing sorts and maps the TOVS data set into a form that is compatible with the C1 format. This process includes sorting by GMT and date, mapping into the C1 map grid, and projecting the profiles onto the standard C1 pressure levels. The first stage of data quality checks is also performed. The next part of the processing will conduct modest interpolation and extrapolation to fill some of the data gaps. Remaining gaps will be filled with a climatology obtained from A. Oort at NOAA GFDL. In the final version of the TOVS data, each profile will be labeled to distinguish between actual observations, extrapolated observations, and climatology.

The implemented changes to the cloud detection step of the algorithm are being tested to insure that the majority of the results remain unchanged. The effect of the changes is to eliminate some bad data effects, to revise the clear sky radiances slightly when an extreme value is used, and to improve the VIS clear sky radiances by using intercomparisons of similar surface types. An improved method of interpolating the IR radiative model results to specific satellite zenith angles is being implemented in the production code. This is the last significant change in the radiative analysis part of the algorithm. There are a number of minor revisions and changes in output content that are needed to completely separate the VIS- and IR-dependent cloud properties. Completely new counts-to-quantity conversion tables have been designed to make these conversions universal in the complete C1 data production system and to insure that the proper data precision is maintained throughout. Refined procedures for handling grid cells that contain a mixture of land and water or day and night pixels have been implemented and tested.

The "old" algorithm has been applied to the January 1984 data set (with no normalization for GOES-6 data and no NOAA-8 data). The C1 data set will be sent to the ICA next week after quality checks are completed.

The revision of the B3 data documentation has been mailed out by WMO; copies were received by the GPC this week.

ISCCP Central Archive (ICA):

The ICA continued to receive B1 data from JMA, CSU, ESA, AES and NOA in a routine manner.

The health of GMS-3, METEOSAT-2, GOES-6, GOES-7, NOAA-9 and NOAA-10 remained good. Launch of NOAA-H has slipped to 5 November 1987.

Revision of the IR count translation tables for GOES satellites.

Delivery of BC data for GOES-6 for January 1984 through July 1984 and for January 1985 and January 1986.

Delivery of GMS B3 data for August 1983 through January 1985.

Delivery of NOAA-8 B3 data for October 1983 through June 1984.

Delivery of B3 data for 1985 and 1986.

Obtaining NOAA-10 data over the Indian sector starting in December 1986.

Arranging for the delivery of INSAT B1 data.

Beginning the delivery of the correlative data sets.

Completing final revisions to the cloud algorithm.