Navigation Spreadsheets

At the fifth anniversary of our website’s launch we review some of Navigation Spreadsheets functions. All three examples are taken from the 2014 Nautical Almanac Commercial Edition.

**1) Ephemeris (almanac data), Venus GP on 2014 May 5 at 13h 15m 18s (p. 256):**

**venus.xls**

**Input:**

UT: 2014 May 5, 13:15:18

**Output:**

GHA = 58º 58.0’

Dec = S 0º 14.1’

**2) Sextant altitude corrections (Venus, p. 259)**

**alt_corr_xls**

**Input:** Hs = 4º 32.6’

**Output:** Ho = 4º 17.6’

**3) The calculated altitude and azimuth (pp. 279-280)**

**intercept.xls**

**Input:**

GP: GHA = 53º Dec = S 15º

AP: Lat = N 32º Long = W 16º

to which we add Ho = 30º 30.0’ in order to allow the calculation of the intercept and the plotting of the LOP.

**Output:**

The resulting LOP (intercept 38 NM away, azimuth 223) is plotted with the T-Plotter.

As it was also calculated by *intercept.xls* this LOP crosses:

the AP’s meridian at 52 NM north of the AP

the AP’s parallel at 56 NM east of the AP

(first published on February 15, 2014)