NUMBER 54

DATE: 02/04/88

Sector Processing Center (SPC):

During December, NOA, ESA, CSU and JMA collectively processed greater than 95% of A data into B1 and/or B2 data. AES processed 72% of the A data into B1/B2.

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

JMA reported correction of a software problem that introduced "striping" in the AC images. All outstanding AC data with this problem have been re-created and delivered to the SCC. JMA also will provide to the GPC with the missing navigation information for June 1984 as requested. JMA plans to begin production of B2 data for the GPC, in place of B1 data, in April 1988.

CSU reports that the 0846, 1146, 1745, 2045 and 2345 GMT images are now being transmitted by NOAA/NESDIS as partial images that clip off the top and bottom of Earth. These images start randomly between scan line 51 and 151 and end randomly between scan line 1451 and 1671. The inclination of GOES-6 will now be allowed to grow one degree per year for the remaining life of the VISSR; remaining fuel will be used for station keeping. This may have some affect on navigation accuracy. CSU has detected an inconsistency between the navigation tables and software that began with the new AAA format; apparently, a change in the sign of the parameter ETA to a plus improves the navigation accuracy.

AES reported data losses on 14 and 23 December caused by a software error which has been corrected.

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.

An adjustment of the IR calibration of GOES-6 B3 data from 23 February through 2 March 1984 by 2 K has been done to offset the anomaly discovered in the QC inspection of these data. This anomaly is probably associated with the failure of a heater in the instrument, reported by CSU. A new version of the affected B3 data tapes will be delivered to the ICA.

Production of the GMS B3 data has been completed through January 1985. Data for July 1983 through January 1984 has been delivered to the ICA; the remaining data are now being prepared for shipment. B3 data for June 1984 will be re-processed upon receipt of the navigation information from JMA.

Upon request, the GPC sent a copy of the B1-to-B2 software that has been used in the production of GMS B3 data, along with sample data sets, to JMA.

The normalization of NOAA-8 to NOAA-7 has been refined by using the final method used for NOAA-9, which includes corrections for solar zenith angle differences. Since these corrections are very small, no change in the adopted normalization was required. Production of NOAA-8 B3 has started with three months already completed. These data will be delivered after a final check of the normalization to NOAA-7 for each month.

Once the NOAA-8 data are delivered, all B3 data will have been completed for the period July 1983 through January 1985. Once the calibration of NOAA-9 is resolved, delivery of B3 data beyond January 1985 will begin.

During the past two months a number of refinements of the B3 processing software have been completed to improve error checking routines. These imporvements arise as new kinds of errors are encountered in the data. The NOAA B3 processing software has also been generalized for a variable number of spectral channels. All procedures in the B3 production are now fully integrated and automatic.

The final tape version of the ice and snow data for July 1983 through December 1984 has been produced; delivery will occur as soon as the documentation can be completed.

A modification of the TOVS processing was found to be needed since the tropopause temperatures and pressures in the TOVS data are incorrect over the polar regions: even though the temperature profile exhibits a distinct minimum at pressures of 50 - 100 mb, the TOVS processing produces values of 200 - 300 mb in these areas. The processing has been altered to use which ever "tropopause" is at lower pressure, bringing the TOVS into better agreement with climatologies. Full production of the ISCCP version of TOVS has been started with three months completed already. Delivery of these data to the ICA will begin next month after the tape format is revised and documentation completed.

Modification of the cloud detection algorithm is complete. Some few mechanical changes are needed to standardize internal data set headers throughout the production system and to install QC procedures. Test production began two weeks ago to provide the statistics for tuning the final thresholds; analysis of these tests will be completed next week.

All testing of the radiation code has been completed, including a verification of all optical constants used to calculate ozone, water, and cloud effects on the radiances.

Changes in the diagnostic step that produces the C1 data are nearing completion; revisions to the C1 tape contents and format remain to be completed.

Some changes in the C data production system software have been completed over the past two months. These include better management tools that include libraries of the B3 and TOVS data, the results of the QC inspection and information about other operational anomalies, and a terminal display that provides a compact summary of the current status of all data sets in the production system. Since this system is the third one to be designed, a few improvements over CLIPS have been devised; these will be migrated to CLIPS in the near future. In addition, testing and adjustment of the two-stream system has been conducted.

Full C production should be started within one to two weeks; delivery of the first two months of C1 data (July 1983 and January 1984) is expected in early March.

Documentation that must be completed includes: revised B3 information to include GOES-7 and NOAA-10, information about the CD data sets (ice/snow and TOVS), and new C1 tape documentation and description of the cloud algorithm. The B3 document is planned for revision in spring/summer to include all information for B3 data through 1987. The C1 documentation will be done in two stages: a briefer document to accompany the C1 data tapes and a more extensive document to describe the cloud algorithm. The first of these should be completed within thm next two months; the second should be completed this summer or fall.

ISCCP Central Archive (ICA):

The ICA continued d be completed within one to two weeks. These include tests of the ocean surface VIS relfectance model, revised procedures for calculations involving small values of cloud optical thickness, revised treatment of the TOVS temperature profiles, and further tests of the adjustment of thin cloud top pressures to account for transmission of IR radiation from the surface.

Changes in the diagnostic step that produces the C1 data will begin next week.

Development of the cloud 6 for January 1985 and January 1986.

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

Delivery of all B3 data for 1985 and 1986.

Obtaining digital sea ice data for 1985 through 1987.

Beginning delivery of the final version of C1 data.

Delivery of special C data sets for the polar workshop, FIRE, WGNE, and ERBE.