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The Satellite Menu provides access to various types of satellite imagery. These data are received via the SBN.

From the initial deployment of AWIPS through 2002, GOES East and West had essentially matching imagers from the GOES 8-11 series. However, GOES-12 was moved into the GOES-East position in early 2003, so sites are receiving slightly different suite of GOES imagery because of the imager differences exhibited in Table 2.1.6.9-1. Sites that change to GOES-12 as their primary satellite will experience more imagery changes than sites remaining with a satellite from the GOES 8-11 series. Sites that switch back and forth between GOES East and West should be especially aware of the imager differences tabulated above.

The D-2D Satellite menu at sites correctly configured to receive data from GOES 8-11 should appear much like that shown in Exhibit 2.1.6.9-1, while the Satellite menu at sites configured for GOES-12 and later should resemble Exhibit 2.1.6.9-2. Now that GOES-12 is activated as GOES-East, large-scale composites of 3.9m and 12/13m imagery (and large-scale imagery derived from those channels) are discontinued. Thus, they are disabled at D-2D's two largest scales (i.e., the North American and Northern Hemisphere scales).

The suite of GOES imagery on the SBN consists of some single GOES-satellite sectors and some GOES East/West composites. The more local sectors tend to be from one satellite (typically the closest GOES satellite), whereas the larger-scale sectors are usually two-satellite composites. Some compositing is done by NESDIS when the imagery is mapped. In addition, the AWIPS site software automatically performs some compositing to maximize the completeness of the coverage when the imagery is displayed in D-2D.

With the following exceptions, all of the products on the Satellite menu are based purely on the imager instruments aboard GOES East and/or West:

1. The GOES Sounder Derived Product Imagery submenu displays the following data: Lifted Index, Total Precip Water, Cloud Top Height, and Skin Temperature. Since this imagery is based on the GOES sounder instrument, there are several important differences between these products and the other (imager-based) imagery. The main differences are that the resolution is no finer than 10 km, the product update frequency is driven by the sounder instrument (AWIPS receives a set of GOES East/West composite DPI once per hour), and the areal coverage is based on that of the sounder scans (which is somewhat less than the areal coverage provided by the imager).
2. The GOES and POES Sounding Data Availability Plot displays the locations where GOES and POES temperature and moisture profiles are available. These soundings are displayable on a Skew-T/log P chart using the Points tool and the Volume Browser. Soundings from the GOES satellites are made only in relatively cloud-free areas, whereas POES systems produce temperature and moisture soundings in clear and cloudy atmospheres. Each hour, NESDIS provides the latest soundings from GOES East and West. Although the GOES East and West sounders yield soundings over a broad area, the default AWIPS configuration retains soundings only from within each site's Regional D-2D scale domain.
   POES soundings are generated approximately every 12 hours and have more global coverage.
3. The 4 Sat Composite products are based on imagery from four geostationary satellites: GMS, GOES West, GOES East, and METEOSAT. These composites are disseminated via the SBN's OCONUS channel and are, therefore, unavailable to most CONUS sites.

GOES East and West each feature a five-channel imager and, apart from the exceptions above, all imagery available on the Satellite menu are based on either one or two imager channels from one or both GOES satellites. The current series of GOES satellites consists of nine spacecraft, with pre-launch designators I-Q and post-launch designators of 8-16 (the latter designator assigned when the spacecraft achieves geosynchronous orbit). At any given time, two satellites of this series will be operational, one situated over the equator at 75W longitude (called GOES East) and the other situated over the equator at 135W longitude (called GOES West). Thus, for example, when GOES-I achieved geosynchronous orbit a few weeks after its launch, it was renamed GOES-8. A few months later, upon successful checkout of the satellite at 75W, GOES-8 became the operational GOES East spacecraft.

The imagers on this series of satellites are similar, but not identical. The primary differences involve the availability of one of two long-wave channels (12u or 13u) and the resolutions of certain channels. The principal attributes of the GOES I-Q series imagers are summarized below in Table 2.1.6.9-1.

Table Notes:

1. The approximate imager resolutions shown are the finest the instrument provides for each channel. NESDIS provides some AWIPS sectors (such as large-scale hemispheric composites) at reduced resolutions (e.g., 8-24 km).
2. The central wavelength for channel 3 is 6.7m on GOES 8-11 and 6.5m for all other GOES satellites in the series.

The GOES imager instruments operate in various modes, which affect the frequency and coverage of some imagery provided to AWIPS. The default mode is referred to as "Routine" mode, and the imagers most often scan in this mode. The other common imager mode is "Rapid Scan" mode. NESDIS commands the GOES East and West imagers (independently) among (chiefly) these two modes, usually in response to NWS requests. In routine mode, the imager scans four CONUS sectors per hour; in rapid-scan mode, the imager scans typically eight CONUS sectors per hour. To conserve AWIPS system memory use, satellite imagery is sometimes displayed with predetermined, scale-dependent time intervals. The imagery is generally displayed at all intervals for the Regional scale and below (i.e., 15 minute intervals in routine mode and generally 5-10 minute intervals in rapid-scan mode), at 30-minute intervals for CONUS scale, hourly for the North American scale, and every 3 hours for the Northern Hemisphere scale. However, there is also a set of menu options in the "NH/NA/US every image" section of the Satellite menu. This menu section is oriented toward the larger scales (i.e., Northern Hemisphere [NH], North American [NA], and CONUS [US]). Selecting satellite imagery from this menu section loads every available image for display. Note that larger scale imagery (i.e., from the NH and NA scales) is ultimately limited in frequency not by AWIPS but rather by the availability of scans from the GOES satellites. Large-scale northern hemispheric imager scans are produced only every 30 minutes. A complete "full disk" (i.e., most of the western hemisphere) image is scanned only once every 3 hours per spacecraft.

A Water Vapor/Infrared (WV/IR) combination product is available in this menu. In this product, the IR Window (11 micron) data replaces water vapor pixels where the cloud top temperature is below -35 C. Other menu entries display images that are differences between two channel images. For example, the selection of the 11u-3.9u menu entry will display the temperature difference between a channel 4 and a channel 2 image (both from the same time period).

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