Glossary

• APRS - Automatic Position Reporting System. An amateur radio system originally developed to maintain an ongoing record of the location of a mobile radio-transmitter. It has been expanded to allow reporting of weather information within a position report. Originally restricted to reporting via amateur radio, it is now possible to send (and receive) these reports via the Internet. The Internet APRS system feeds data into the USA Hurricane warning center and other NOAA systems.

• ASOS - Automatic Surface Observing Station. Used for automatic METAR report generation. Has a ceilometer to measure cloud height and type automatically.

• CSV - Comma Separated Values/Variables. A computer file format in which individual data values are separated from each other by commas. Used in Excel and database software.

• DDE - Dynamic Data Exchange. A data transfer mechanism available within MicroSoft Windows that allows computer programs to directly exchange data. For example, WD can make its data available to EXCEL spreadsheets using DDE.

• FTP - File Transfer Protocol. FTP allows local or remote client and server machines to share files and data using the TCP (see also) transport mechanism. FTP is an interactive protocol with provisions to Copy (in either direction), Rename, or Delete files on a server machine.

• HTM - A file type designator. Most commonly used in Microsoft Windows computers to indicate that the file contains HTML content.

• HTML - HyperText Markup Language. The markup language with which World Wide Web (WWW) documents are written. It allows you to create hypertext links, fill-in forms, etc.

• HTTP - HyperText Transfer Protocol. The set of messages used between Web browsers and servers to provide a means to deliver requested documents, e.g. HTML files, to a user.

IP Internet Protocol - Data to be transmitted is enclosed in a "datagram" with originating and destination addresses attached. Individual datagrams are sent via whatever route makes sense at that instant. Successive datagrams between the same points may take different routes. Datagrams are sent on a "best effort" basis and are not guaranteed to reach the recipient.

ISP Internet Service Provider - the company you have chosen to give you Internet access, e.g. AOL; Plus Net; Freeserve, etc, etc.

LAN Local Area Network

METAR An acronym derived from the French, and basically means "aerodrome weather" - This weather observation coding format is the primary format for weather data distribution in North America, though it is used at larger airports in other regions. The format is rather reasable and is designed mostly for the aviation sector. METAR observations are usually taken every hour. (from "Weather Forecasting Handbook", 5th ed., Tim Vasquez)

MIME Multipurpose Internet Mail Extension - A definitive list of file types used by Email clients and Web Browsers (among others) to determine how to process the content of a file.

NOAA National Oceanic & Atmospheric Administration - A part of the United States Department of Commerce, and is the parent agency of the US National Weather Service.

SMTP Simple Mail Transport Protocol - The set of processes used for email transmission by the bulk today's internet email systems. In practice, this protocol gets the email from the originator to the email server supporting the recipient(s). Actual email receipt is handled using either POP(see also) or IMAP(see also).

SYNOP Synoptic Observation- This observation coding format is used worldwide, and comprises the primary method for weather distibution outside of North America. The format, designed mainly for meteoroligists, consists of blocks of numerical data. The observations are usually taken every 6 or 12 hours (sometimes every three). (from "Weather Forecasting Handbook", 5th ed., Tim Vasquez)

TCP Data to be transmitted is broken up into "packets" of a specific number of characters for transmission over a network within an IP (see also) envelope. Since the nature of computer networks is such that the delivery of packets can not be guaranteed, each packet also contains additional information that the receiving computer can use to assure that all packets have been received and placed into their correct order.

URL Uniform Resource Locator - The unique address of a document on the World Wide Web. A URL consists of the document name preceded by the hierarchy of directory names in which the document is stored, the Internet Domain name of the server that host the file, and the software and manner by which the browser and the document's host server communicate to exchange the document.

WAP Wireless Application Protocol - Data that can be seen on mobile phones that have this facility.

Wunderground A contraction of Weather Underground - A program of the University of Michigan that posts weather observations from private weather stations around the country on a web site.

Windrun A measurement of how much wind has passed a given point. A wind blowing at three miles per hour for an entire hour would give a wind run of three miles.