A measurement of the position of the moon in order to calculate longitude from lunar distance.
More example sentences
- He speculated that he would continue to ‘amuse’ himself in attempting to determine Monticello's longitude but with lunar observations.
- At the Greenwich Royal Observatory Halley used the first transit instrument and devised a method for determining longitude at sea by means of lunar observations.
- If you had a chronometer, you would use it to measure longitude all the time, not just "when lunar observations were impractical."
Definition of lunar observation in:
- The US English dictionary