Spreadsheet many_body_fix.xls implements a procedure for computing a location from multiple lines of position obtained on a moving vessel. This navigation problem typically arises from a round of observations acquired during twilight. Enter the desired UT of the fix in cell A2, vessel speed in knots in cell B2, and course (track) in cell C2. The initial best guess for the position goes into cells E2 and F2. The observational and GP data start in line 9 and are entered into columns A (name), B (UT of observation), C (observed altitude Ho), E (GHA), and G (declination). The computed coordinates are displayed in row 6. The spreadsheet performs a block of four iterations of this procedure. On output, the value d in cell D4 should be less than 20 nautical miles; if that is not the case, copy cells A6 and D6 into cells E2 and F2 and repeat this procedure until convergence is reached.