why did old (like 90s/2000s) GPS take up to 15 minutes to get a lock, in giant bulky units, but my running watch gets it in 15 seconds?

Question

why did old (like 90s/2000s) GPS take up to 15 minutes to get a lock, in giant bulky units, but my running watch gets it in 15 seconds?

In: 3751

Answer 1

Back then, gps also used to have an accuracy limit of 300 meters. It was done to prevent usage in weapons as GPS was primarily a military system. With a 300-meter inaccuracy, you would miss the White House