Spreadsheet dr.xls computes the dead reckoning (DR) position (row 11) from the previous known position (cells A3 and B3), average speed in knots (cell A7), time interval in hours (cell B7, formatted as a regular floating point number), and course (cell C7).
The following image shows the spreadsheet dr.xls.
Summary for spreadsheet dr.xls:
Input cells: A3, B3, A7, B7, C7
Output cells: A11, B11, C11, D11, E11, F11
2. Dead reckoning fix of Estimated Position along LOP
When
only one line of position (LOP) is available, it is possible to find
your estimated position (EP) by using the dead reckoning position (DRP)
as a guide. Spreadsheet dr_fix_lop.xls finds the EP as the
point along the LOP which is closest to the DRP. The previous known
position is entered in cells A3 and B3, average speed in knots in cell
A7, time interval in hours in cell B7 (formatted as a regular floating
point number), and course in cell C7. The LOP is defined as usual by
the GP and Ho (cells D3, E3, and F3). The EP is displayed in row 11.
The distance (in nautical miles) and bearing from the DRP to the EP are
shown in cells C13 and F13, respectively.
Summary for spreadsheet dr_fix_lop.xls:
Input cells: A3, B3, D3, E3, F3, A7, B7, C7
Output cells: A11, B11, C11, D11, E11, F11, C13, F13
The problem preset in this spreadsheet is a variation on the one treated in The Celestial Navigation Mystery Solved by David Owen Bell on p. xliii (Problem 1).
Buy Now
