Yes, Chicago is one of the toughest cities for GPS in the US. Here's a peek into average building heights in downtown Chicago. Anywhere red, yellow, or orange

Yes, Chicago is one of the toughest cities for GPS in the US. Here's a peek into average building heights in downtown Chicago. Anywhere red, yellow, or orange we expect to have poor sky visibility. GLONASS being more popular has made Chicago slightly less challenging, before you could have trouble even seeing enough satellites to get a fix. https://imgur.com/a/3bjiiRw https://imgur.com/a/3bjiiRw