Browse Generation and Browse Metadata Management

M. Sarges, G, Kluck, C. Moschell, J. Faundeen

Definition of Browse.

The team accepted the current definition of EDC's AVHRR browse that consists of a single band (channel 2 for day and channel 4 for night) subsampled every 4th line and 5th sample.

The purpose of EDC's browse imagery is: 1) To screen for cloud cover, 2) To note image quality (line drops, etc.) problems, and 3) To confirm geographic locations. Cloud cover detection is the primary purpose for EDC’s AVHRR browse.

Browse data base records transfer to the AVHRR Production Data Base (AVPDB) & GLIS.

GLIS metadata and browse files are updated multiple times per day to reflect ingested scenes quicker.

Transfer of the Browse data/metadata to GLIS.

Data Management traps duplicate coverage scenes by a initiating weekly a program that will compare start and stop times. Scenes that fall entirely within another will be deleted if they originate from the same receiving station and if the larger scene is of acceptable quality.

Data Management traps and compares duplicate scene IDs and investigates which one of the scenes should be deleted. Re-broadcasted scenes are be logged by Data Management and correlated to the correct browse file utilizing a time-stamp function that was implemented 12/24/91.

Browse data storage, i.e., platform/device and Browse management/QA.

Given (70) 15-minute pass scenes ingested per day, the resulting browse imagery would total 39 megabytes of 8-bit subsampled data (39 meg X 365 X 1.5 = 22 Gig per year). By utilizing the WORM drive(s) and JPEG compression techniques (13:1 or 10:1) it appears that supplementing hard disks is not necessary (using 13:1 results in 1.7 Gig).

Other Activity, i.e., facsimile generation for CS and microfiche.

The generation of fiche using the Colorfire processor has been implemented.

The microimage fiche are categorized as: A = North America HRPT from EDC, Wallops, and Fairbanks; H = Other HRPT data and all LAC data. 1-km participants can receive microfiche through a subscription service provided by Customer Services Data Management. China is the only participant utilizing the subscription service to date.

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U.S. Department of the Interior | U.S. Geological Survey
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Page Last Modified: Wednesday August 24, 2005