Satellite images are available to view online, but you may need some guidance when interpreting them. There are plenty of resources both in books and online that can help. Even if you are not an expert, it is still beneficial to learn how to read the National Weather Service radar imagery.
As a result, it has become popular among street racers and those who do not mind dipping into the realm of illegal modifications to purchase and install police scanners or radar systems. Although there are not general laws that govern the use of these systems across all American jurisdictions, there are some widely implemented limitations that protect law enforcement officials and fair business practices.
There are certain areas that directly prohibit the use of these devices. In these jurisdictions, it is illegal to use a police scanner or a radar device entirely without being a proper exception, regardless of the intention of the device. There may be exemptions for cab drivers and truck driving companies that use these devices to share information about routes or customers.