LA Variable definition table is implemented in the XGDATA system. This tableGdefines the attributes of all database variables extracted by XGDATA. NSoftware independence with the database is obtained by isolating this portion Kof the system. The left three columns of the table indicate which databaseIthat variable is defined for. If an integer is in the appropriate columnIthis indicates the column in the database where that variable is located.NStorage units and print units are also defined for these variables. A storageKunit is representative of the integer value stored on disk. If a latitude Mfield has a physical value of 10.0 the value stored on disk is 800. This wasLdone because it only takes two bytes to store the integer value 800 while itItakes 4 bytes to store the floating point value of 10.0. The Print valueOis a remnant from the old XG system and is only used by module XBIN. There is Na two character short abbreviation for the variable name in the fourth column.LThe fifth column contains a textual description of that variable, while the Hfifth is a format statement which is used for printing the results to a *print file with sufficient decimal places.C.hl2 Entering the Variable Identification and Constraints Properly.EAll variables in the table below may be constrained, in addition the Mvariable may be extracted by the application module. For example if the userLis extracting latitude and longitude he may simultaneously constrain on limbMangle and latitude, or some other variable and not extract it. When enteringNthe variable to be extracted, binned, or plotted the correct format for doing so is .ltH "lat,lon,t2" If more than one variable is requested, surround it by Hquotes. The proper way to enter a variable is to use the two character Lvariable name in column 4 of the variable definition table on the next page.AWhen entering constraints the following rules must be adhered to:; 1) Use the two character abbreviation whenever possible.O 2) A constraint is characterized by a 2 character id, minimum val, max. val.P e.g. "LA,-45.0,45.0", This will constrain latitude between -45.0 and 45.0.3 3) ALWAYS enclose your constraints with "quotes"H 4) You may perform a difference between two variables by entering the( operation in the following manner.G e.g. "T2-TM", which will difference the 20 micron from the model  temperature. .el .skip