During the epidemic, many people are more puzzled is why through the big data can check the personal trajectory, really amazing, is it through the cell phone can check where they went? Not more than 4 hours have track? Big data is how to find personal trajectory? Below, quickly and I understand the relevant knowledge!

Wouldn't you be able to turn off your phone and find out what you've been up to for 14 days?

You can check it out. Turning off the phone and unplugging the card doesn't affect the phone's positioning.

Only when you unplug the phone card, you can still find it. Unless you remove the SIM card at the same time you remove the phone's battery, geographic information is known to interested parties through the phone, no matter where you are.

But in reality, the smartphones that are commonly used today are basically all-in-one devices, and you can't normally take the battery out of the phone. A lot of software can also access the Internet with the phone turned off. As soon as the phone is turned on, it tries to access the base station, and once the base station recognizes the phone, even without a SIM card, it can correlate its relevant information through the phone's unique identifier, the IMEI number.

How Big Data finds out about a person's trajectory

It's the digital age, and cell phones can be carried around for a long time. Therefore, the cell phone's mobile whereabouts trajectory also effectively represents the person's whereabouts. Our cell phone, whether it is a smart phone or a traditional feature phone, as long as the insertion of the phone card, from power on to power off, always with the mobile, telecom, or Unicom network base station to maintain a momentary contact. It's not that you only communicate with the base station when you make a phone call.

This constant connection is called signaling exchange. Operators have a clear idea of where their base stations are located, for example, on the upper floors of a neighborhood. According to your cell phone and base station communication contact can be roughly judged in which small area you have appeared in the region, the general city is about 300 meters within the scope of the rural is about 500 meters within the scope. This is probably the principle behind the communications big data trip card service launched by carriers this year.

And other sources of whereabouts data can be more broadly included in your contact with public **** facilities, such as the use of public **** transportation, moving tickets in and out of the station are systematically recorded. Buses, subway stations, highway entrances and exits and so on. It can be said that in the era of digitization, intelligence, a person's whereabouts are traceable.

Changing a cell phone number will change the trip card

Re-buying a phone card will not change the trip, it depends on whether you set the trip in the phone or in the phone card most of the time in the set in the phone above, then even if you re-exchange the phone card, then the trip should not change.

The trip card is launched by the three major carriers, is based on the user's cell phone number needs to be updated regularly location area, receiving base station to send system message signaling, base station can know the user's current location to form the user travel track.