Getting Started About the Compact Discs The data on these CD-ROMs are written in the International Organization for Standardization (ISO) 9660 format. Mastering of the CD-ROM disc and replication of the copies were done by Disc Manufacturing, Inc., Anaheim, California, under contract to NGDC. Handle the CD-ROM carefully to avoid damage. Dust, scratches, ink, paint, fingerprints, and high temperatures may corrupt this media. With careful handling and proper storage the discs have an expected lifetime of ten years. Installing the ACcess software About GeoVu GeoVu, the access software provided with this package is designed to help users identify data of interest and export them to an application of their choosing such as Geographic Information System (GIS) packages. Using GeoVu, researchers are able to view numerous CD-ROMs, as well as their own data collections, with the same intuitive user-interface. The GeoVu menu system allows the user to: o select a specific data set o identify the geographic area-of-interest o output data from the compact disc onto hard disk or floppy diskette in any of several output formats o view the geographic location of the data observations GeoVu was developed with funding support from NOAA's Climate and Global Change (C&GC) Program and from the NOAA's Earth System Data and Information Management (ESDIM) Program. Setting Up Your Computer GeoVu will operate on any IBM PC-compatible personal computer with a graphics board and a CD-ROM reader. The software is not designed to operate on other types of computers. However, we expect future releases of access software which will operate on UNIX and Macintosh. Two IBM PC-compatible versions of GeoVu are available to access data on the Global View CD-ROMs—the Microsoft Windows version and the native DOS version. Since the Windows version has many more capabilities and fewer memory limitations, it is highly recommended over the DOS version. For example, the DOS access software requires 500 kilobytes of free RAM. Both Microsoft Windows-based and DOS-based software are provided on Global View CD-ROM Disc 1: Coastal Change Analysis Project. Installation instructions are in the "win_read.me" and "dos_read.me" files. The executable code is contained within a "setup" and an "install" program for the Microsoft Windows-based and DOS-based software, respectively. The Windows version is installed following standard protocols (e.g., from the Windows Program Manager File menu, select the Run option, and type "L:setup", where L is your CD-ROM drive designation). Three megabytes of hard disk space are required to load and execute the software. A large-capacity hard disk is needed if large files are to be copied from the CD, or if many screen images are to be saved. We recommend using a computer with at least 640 kilobytes of RAM and 20 megabyte hard disk (minimum). A math coprocessor will significantly speed up the application. If the DOS file and buffer limits are set too low, the access software will not run or will lock-up. We suggest setting both to a minimum of ten. Future Software Release Plans Future releases of GeoVu will expand platform compatibility to include UNIX (Sun with "Open Look" X-windows) and Macintosh Windows. Please send all inquiries about updates to Allen Hittelman via the address provided on page four. The GeoVu access software (including updates) is available free over Internet or for a diskette copying fee. Data ORGANIZATION Data Set Descriptions Data set descriptions can be found in multiple locations: 1. Within Access Software: Help files typically identify the source of data, the size and structure of the file, processing characteristics, and references. 2. In Documentation Files: Numerous documentation files define different characteristics of the data. These are often identified as .TXT, .HDR, .PCX, and .DOC (IDRISI) files. 3. Using FREEFORM: Additional documentation and reformatting facilities are available with FREEFORM, included in the "Supplemental" directory on the compact disc. Field Naming Standards A standard naming convention was used to describe the parameters (fields) within each data record format on the compact disc. While parameter (field) names have been made similar, each format may vary somewhat with respect to precision and units of measure. Even latitude and longitude fields, which were standardized with respect to sign conventions, contain data with degree units in either four or five decimal places. Header Structure Header files, with an ".HDR" extension, are associated with most data files on the CD-ROM. These ASCII files are found on the CD-ROM; however, they may also appear in the access software directory (especially if information has been expanded or corrected since the pressing of the CD-ROM) or on your workstation's hard disk in conjunction with a data file that you extracted from the CD-ROM. The header file consists of a series of records of the form "field name = field value". Within each record, the field name (up to 60 characters) is followed by an equal sign, and the field value (less than 80 characters). Each record is terminated by a standard DOS (UNIX) record terminator(s) (i.e., carriage return or new line). An example of a header file is: file_title = TerrainBase global 5-minute DTM vers.1.0 data_type = image data_byte_order = little_endian upper_map_y = 90.0 lower_map_y = -90.0 left_map_x = -180.0 right_map_x = 180.0 number_of_rows = 2160 number_of_columns = 4320 grid_size(x) = 0.08333333 grid_size(y) = 0.08333333 grid_unit = degrees grid_origin = upperleft_x grid_cell_registration = center of cell map_projection = Lat/Lon missing_flag = 0 elevation_max = 7830 elevation_min = -9919 elevation_unit = Meter palette = topo comments = Worldwide composite of regional DTMs The values associated with certain field names are treated as key-word-values and follow specific conventions: data_type: POINT (tabular data), VECTOR (data pairs that are connected), IMAGE or RASTER (two-dimensional grids) grid_origin: This convention both locates the origin and describes the sequence of the grid's order. Valid values of grid origin include upperleft, upperright, lowerleft, lowerright, and sequence identifiers are either "x" or "y". For example, in "lowerleft_x" the origin is in the lower left and the sequence of the grid proceeds in the x (i.e., longitudinal) direction, eastward. In other words, the sequence is from left to right then up, with the first point of the grid at the lower left and the last point of the grid at the upper right. grid_cell_registration: Documents the registration of the data within a single cell pixel: Center of Cell Bottom Left Corner Bottom Right Corner Top Left Corner Top Right Corner projection: Currently available projection keywords include: none UTM State plane Albers conical equal area Lambert conformal conic Mercator Polar stereographic Polyconic Equidistant conic Transverse Mercator Stereographic Lambert azimuthal equal area Azimuthal equidistant Gnomonic Orthographic General vertical near_side perspective Sinusoidal Equirectangular Miller cylindrical Van der Grinten Oblique Mercator Lat/Long