Lotus 123 - a graphical spreadsheet program used for geophysical calculations

With the upsurge of personal computing on microcomputers several spreadsheet programs have been introduced to perform simple business calculations (budgetting, calculation of project costs, etc.). They provide commercial managers with flexible computing facilities without the need to write additional programs or have costly staff available for relatively simple computing problems. The most widely known programs are Visicalc, Multiplan and Lotus 123. The program under discussion, Lotus 123, was originally developed for the IBM-PC (MS-DOS) and compatible 16 bit microcomputers. This article describes the application of the program to filing and simple processing of geophysical data. The following two examples, taken from fieldwork done by students from the State University, Utrecht in southern Portugal during June 1985, will be discussed: (1) processing of VLF data with a five-point first-derivative filter; (2) field processing of gravity data (corrections for instrument drift, height and latitude, and calculation of the Bouguer anomaly). The purpose of this article is to show geophysicists how to use this user-friendly program in their profession. As far as training is concerned, the use of a standard program is profitable. Data entry is always done in the same manner no matter whether, for example, gravity data or VLF data are involved. It is even possible that users are already acquainted with Lotus 123 from other applications, such as business calculations. It is my experience that students with varying computer expertise can handle data entry and processing completely within a few afternoons. A quick start-up of data filing and primary processing can almost be guaranteed. It took me only one afternoon to establish the spreadsheets for both examples after the fieldwork had already begun and the first gathered data were on my desk. Two further days were needed to refine the spreadsheet model, while the field data were already being processed.