Real test CLLocationManager inaccurate positioning

- (Void) locationManager: (CLLocationManager *) manager didUpdateToLocation: (CLLocation *) newLocation fromLocation: (CLLocation *) oldLocation
{

location = [newLocation coordinate];
curLat = [NSString stringWithFormat: @ "% f", location.latitude] ;/ / get latitude
curLng = [NSString stringWithFormat: @ "% f", location.longitude] ;/ / get longitude

Positioning is not accurate, there are deviations
1 km of theReal test
}
Reply:
How do you judge inaccurate? Compare and maps is it? Domestic map coordinates are encrypted, and certainly no way to match the map
Reply:
Please search

Mars coordinate system

You can know why.
Reply:
State Secrets plugin, also called partial encryption plug-ins or add or SM module, in fact, the real coordinate system artificially plus partial treatment, according to a few lines of code algorithm, the encryption true false coordinates into coordinates, and this plus partial not linear plus side, it shifted around the situation will be different. The coordinates of the encrypted also often called Mars coordinate system.
All electronic map of all the navigation equipment, you need to join the national confidential plugin. First, map mapping maps the company, after the mapping is completed, sent to the State Bureau of Surveying and Mapping, the electronic map real coordinates, encrypted into "Mars coordinates", such a map is published and can be released before the company can make GPS treatment. The second step, all the GPS companies, as long as the need for car navigation, the need to use the navigation electronic map, all need to join the national security algorithms in the software, the COM port to read out the coordinates of the real signal encryption into national requirements confidential coordinates, so, GPS navigation and navigation electronic map can be fully matched, GPS will work properly.
Reply:
So, all the navigation electronic map company, like Navinfo, Ritu, EMG, High German, etc., need to get their electronic map encrypted National Mapping Agency, and all navigation software companies have you need to add encryption algorithms provided by the State Bureau of Surveying and Mapping code own navigation software. And this piece of code, the country is confidential, not public, each to the national mapping agency is encrypted and requires an appointment in a closed environment, the compiler needs to be completed in the main program exe rather not compile the external dll and other files.
Of course, the country's secret plug-in is a charge for the early time, a navigator will need 10 dollars confidentiality plug-license fee, uh, the plug is not white with secrecy, after all, the country spent a lot of money and manpower and how it can be made out of material to protect the confidentiality of national security things to send whatever you use it, the money will be close to normal can be considered to be expected it. Now, it seems the company has been decentralized to the map data, the map data is to see the company's operating status, how many copies will probably ship electronic map, and map data company to receive a one-time how much money, how many millions might be, then the money do you find your own data on the company's navigation software company's customers received it, count on each piece of equipment in the license fee, uh, national efficiency becomes higher, a charge-by-charge ratio directly from the navigation electronic map company navigation software company money to come easy and not so troublesome.
At this stage, some people or organizations for their own interests, the navigation software and navigation maps crack, and discovered the existence of navigation electronic map map bias, so take artificial means to map the anti-encryption, the false coordinates converted into a standard WGS84 coordinates, the most stupid way is linear shift, probably deviation distance of 500 meters, basically anti-back, but the error is large, especially in the case of the north-south distance increase, while the little smart way calculated using matlab tools such as one of the curves, and then reverses back. How horrible that this is in breach of national law behavior, national security, and it was you destroyed, it is a criminal issue, rather than simply cracking software to crack the map of economic crimes. Please be sure to be sure to comply with the laws of the country, do not dry out such a stupid thing out, you can not protect everyone out of trouble, after all, you will become the enemy of the country.
Finally, talk about the evils of secrecy plugin, the benefits can not be ignored, the state for safety reasons, the confidentiality of safety, but the drawback is, creating artificial barriers, very difficult to use, such as navigation software out of the coordinates, not Google Earth software and other international matches, Google Earth and Map in the country is basically waste. The problem is further brought navigation, geocaching, GPS sharing and many other fun activities, they can not expand in the mainland, it really makes very helpless. Of course, there are times when, due to confidentiality issues navigation software plug-ins, can cause navigation and so on. Confidentiality plug is a dumbfounding thing people, just as WGS84 coordinate international coordinate our 54 or 80 coordinates, just as recent national authorities ready to develop leak problem "Image China" counter to google earth. So many, legal insurmountable, but we do not want to artificially create trouble, or for more in-depth economic interests.

Reply:
[Your locaionmanager object setDesiredAccuracy: kCLLocationAccuracyBest]; But Google Maps do indeed offset, this is the state, no way