Generic question... My Garmin Nuvi 350 default factory load consumes about 1GB of space. I've heard it contains about 6 million built-in POIs.
However, this thing knows about essentially EVERY household and business and park and street and landmark in the US. There were 120 million homes in the US in 2001. FAR more than 6 million POIs. Right?
So how does it know when I am pulling up to my cousin's house at 14273 Hickory Street in Nowhere, IL? Rather than a few houses away at 14213 Hickory?
Thanks for any insight on this.
Your actual question seems to be, how does GPS work.
Try this link
You would get a better understanding from Garmin, then you would from me lol.
No. I know how a GPS works... essentially triangulation from a network of sats.
But that tells the GPS unit where it is. My question is about where you want to go... how does the GPS know about 120 million homes and tens of millions of additional locations... When there are only about 6 million POIs pre-loaded.
Homes and businesses are part of the map software itself, not necessarily listed as POIs. However, I have noticed many home listings not showing up in my area. Seems like every 5th or 6th home is actually listed.
The 6 million POIs do not include the address database. That number only refers to those specific points of interest such as food, lodging, etc.
And it doesn't know about every household in the US. What it DOES know is that a certain street segment contains a certain range of addresses. And it attempts to perform a mathematical interpolation to determine exactly where on that street segment a particular address may fall.
a house address is just an address a poi is a actually name and all of the bussiness when you pull up your cousins address it does not actually say your cousins house does it untill you store it under that then its a new poi sory not tryin to sound pushy just trin to explain
Very true. It doesn't say the name of a house. But it does know when I have arrived at an address with uncanny accuracy. To the point that I didn't think it was just attempting an interpolation based on just a range of addresses along a street. If it knew every 4-5 houses, that would make more sense. Still, 20 million homes in the internal (non-POI) database.
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