International Satellite Cloud Climatology Project (ISCCP) B1 Uniform (B1U) Dataset

Data are collected from the suite of weather satellites operated by several nations and processed into B1 data by several groups in government agencies, laboratories, and universities. Data is submitted in multiple formats, depending on the satellite and nation submitting the data. In order to alleviate complexity when creating satellite products, NCEI processes the data into the B1 Uniform (B1U) format, which is used in multiple satellite products. Data are included in the ISCCP H-Series collection, but are a intended as a standalone interim product on their own.

Data Variables:
The primary data variable are the satellite radiance scans: the images. The following is a list of the more prevalent imagery:
IRWIN - Infrared window channel image (~11 microns)
VSCHN - Visible Channel image.(~0.6 microns)
IRWVP - Infrared Water Vaport Channel (~6.7 microns)
IRSPL - Split Window IR channel (~12 microns)
There are many other channels. See documentation for list.

The various file headers contain information on
- navigation (i.e., calculating lat/lons for each pixel and vice versa)
- calibration (i.e., calculating physical values for each image count ... e.g., converting counts to temperature)
- timing (to calculate the time of each scan line).
- and more

Measurement resolution is dependent on the source geostationary instrument. The scans were spatially subsampled to reduce the file sizes. This often results in a spatial resolution of 8 - 10 km near satellite nadir (the resolution decreases away from this point).

The images are provided every 3 hours near (but not exactly at) synoptic hours (00, 03, 06, ..., 21 UTC).

The spatial coverage spans the globe (longitudinally) but geostationary satellites can't really observe the poles. The latitudinal extent is about 65 degrees.

The temporal coverage begins in the 1978 for early SMS satellites. Each satellite will have a different temporal span than another. The globe (longitudinally) can be considered covered beginning in 1982 when there were two satellites of the Western Hemisphere, one at the Prime Meridian and another over the Western Pacific (4 total). The true global coverage (5 satellites) began in 1998.