Paul Vincent Craven
All Rights Reserved
Almanac. Periodically, the GPS satellites transmit an almanac that tells receivers about satellite positions and orbit paths.
Baud. Term used when transmitting digital data over an analog medium, like phone lines or radio waves. It indicates how many times we can switch the data signal per second. It is related to, but not the same as, bits per second.
Bison. Helps programmers create interpreters or compilers for computer languages. The program is covered under the GNU General Public License. It takes a formal LALR(1) grammar and creates C code that can parse it. Bison is usually used in conjunction with Flex.
BPS. Bits Per Second. Binary data is in the forms of ones and zeros. Each one or zero is a bit. BPS is the number of these that we can transmit in a second. The rate is usually equal to or higher than the baud rate.
CFG. Context Free Grammar. Formal specification for a mathematical language. By following the grammar, one can find what is a syntactically valid phrase for the language.
Communications Port. Also knows as a COM port. This is a socket on the back of a computer that allows data from external devices, such as modems.
Differentiation. Complex process by which a stationary GPS is used to correct positional errors of a moving GPS.
EEPROM. Easily Erasable Programmable Read Only Memory. A memory chip that holds its information after being turned off. The information is normally read-only, but it can be rewritten if the hardware supports it. In contrast, EPROMs can only be erased by exposure to Ultra-Violet light.
Flex. A program that quickly matches regular expressions in text files. Also known as a lexical analyzer.
FTP. File Transfer Protocol. Method of transferring files across TCP/IP networks, like the internet.
GPS. Global Positioning System. It consists of a system of satellites funded by the United Stated Department of Defense that transmits information that allows receivers to calculate their position.
GUI. Graphical User Interface. An interface based on graphics, as opposed to text-only.
NREL. National Renewable Energy Laboratory. Governmental agency that researches and promotes renewable energy resources.
Object-Oriented. Object-oriented design is a relatively new concept in computer programming. Instead of issuing commands to a computer, a program creates "objects". Objects can perform actions when the program calls their "member" functions. For example, a graphical window could be represented by an object.
Parse. Taking text input and translating it into machine understood code based upon a given grammar.
Pipe. A communication channel opened on a computer. Data can be passed through the pipe to other programs on a network.
Pointer. A place in memory that holds another memory address. Pointers allow programs to ask and handle memory that is asked for while running. Also, moving a pointer to a large data set takes less time than moving the data set itself.
Pre-emptive. A pre-emptive task can interrupt any other program, even the operating system. Usually this is reserved for when timing is critical, or when a program has frozen.
RCS. Revision Control System. Used in large projects, particularly with multiple programmers. It keeps track of changes in code, and prevents more than one person working on the same code at the same time.
Regen. The ability of the motor to act as a generator when braking or going down hill. The name comes from the word "regeneration".
Registry. A database in Windows NT™ that stores configuration information about the machine, and individual user's preferences.
RFI. Radio Frequency Interference. Electronics can create radio waves which are picked up by other circuits, causing unwanted voltages and currents that adversely effect their operation.
Service. A background computer process that runs behind the scenes. This process does not access the user interface. It is equivalent to a UNIX daemon.
Signal. A signal is used to let a thread or process know when an event occurs. For example, the thread can be suspended waiting for a signal from the communications port that new data has been received.
Thread. A computer process that runs separately from the program that created it, yet still shares the same memory and attributes of the parent program.
UPS. Uninterruptible Power Supply. A battery backup system that filters spikes out of incoming power and provides temporary power if line voltage is lost.