GPS Made Easy (Free Dowload) GPS design is based partly on ground-based radio navigation systems developed in the early 1940’s that were used in World War II. These systems were named LORAN and Decca Navigator and were focused on knowing where the enemy was so they could either attack or retreat depending on the size of the forces. Additional inspiration for modern day GPS systems came when Sputnik was launched by the Soviet Union in 1957. A team of scientists monitored Sputnik’s radio transmissions and discovered that because of the Doppler Effect, the frequency of the... Never Miss Out Again! With our free PDF ebook, that you can even customize, you will never miss out on any Home Improvement, DIY, Real Estate, Family related information or even deals on products and services. Find articles, guides, how to Free PDF ebook downloads Save money when you shop online ...and more!! Click here for your free ebook Free eBook Downloads Anyone? Get five free PDF ebook downloads every five days. Opt out anytime you wish. This is an Opt-In list: Name: Email Address: Free Community Business Ads! If you would like to get... free advertising for your business become a published author show off your expertise boost your credibility get a free listing on your community page, then... Click here find out more about our free publishing here. Back to main index You should always read our disclaimer before reading, downloading or purchasing any information product. Affiliates click here!