iOS定位服务准确性

Question

参考以下代码段，我应该使用什么准确度和过滤值来使位置检测尽可能敏感？

可以假设我正在制造地雷探测器，并且已知地雷的位置。所以我想在用户走进某个区域时立即触发警报。

非常感谢！

//Create a new location manager
locationManager = [[CLLocationManager alloc] init];

// Set Location Manager delegate
[locationManager setDelegate:self];

// Set location accuracy levels
[locationManager setDesiredAccuracy:kCLLocationAccuracyKilometer];

// Update again when a user moves distance in meters
[locationManager setDistanceFilter:500];

// Configure permission dialog
[locationManager setPurpose:@"My Custom Purpose Message..."];

// Start updating location
[locationManager startUpdatingLocation];