The Number of Measurements is controlled at upper right. New measurement positions are added to the end of the list and are evenly spaced. To get all the measurements evenly spaced, first change the number of measurements to 1, tab out of the edit field (or click elsewhere in the window) and then change the number of measurements to the desired value.
The Add to Calculated field is available to adjust for baseline differences between observations and calculated values. This can be set manually or by pressing the Use Mean Offset button, which will insert the mean offset between observed and calculated values into this field.
The spreadsheet of values comprises most of the window. Listed are the horizontal (X) and vertical (Z) positions of the measurement points, the observed value, its uncertainty (if that option is chosen in the Preferences Window), and the calculated value. Clicking on this area and then clicking on the value to be changed will allow you to edit that value. Tabs will move you forward through the list; shift-tab will move backwards. Arrow keys also allow you to move up and down and left and right. Values and the Section Window are changed when the cell being edited becomes inactive (by selecting another cell or another window). Clicking on the header at the top of a column will sort the fits by values in that column. Column widths can be resized by clicking on the dividers between headers.
The RMS Misfit at the top of the window is the root mean square of the differences between observed and calculated values and is updated when calculated or observed values are changed.
You can save current model values as observations using the Paste Model Values command from the Edit Menu. You will be prompted if this would overwrite any existing measurements. The values in the table can be copied as tab-delimited text using the Copy Data command in the Edit Menu. The data can be printed using the Print command in the File Menu and saved to a text file using the Save Gravity Data command from the File Menu. Files saved in this manner can be reopened using the Open... command from the File menu.
You can read in data in a simple text file using the Import Delimited Text... command in the File menu. Files can have header lines that will be ignored (Lines to skip) and the X, Z, and observed gravity values can be in any columns. All three values must be present. Columns are delimited by a single unique character (typically a comma or a tab). You are first prompted for the data file and then you enter the positions of the different data columns and the kind of delimiter to use through the screen seen above.