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2014/10/15 ¤U¤È 10:11:20
iphone Programming Glossary: measurementWhy is my CLLocation speed so inaccurate? http://stackoverflow.com/questions/1180050/why-is-my-cllocation-speed-so-inaccurate good quality GPS signal newLocation.speed 1.0f enough movment for accurate speed and course measurement oldLocation nil oldLocation is nil on the first reading double speed newLocation.speed 3.6 self updateDisplayWithSpeed..
Indoor navigation hardware/software requirements for iOS http://stackoverflow.com/questions/15732181/indoor-navigation-hardware-software-requirements-for-ios is a pattern matching technique where you first build a wireless map of the environment and then match the measurement against this map. Bluetooth same techniques as above can be used with Bluetooth nodes. Of course there's less Bluetooth.. very cheap no extra hardware or initial survey phase are needed. UWB very accurate techniques based on time of flight measurements. Requires expensive hardware for both transmitter and receiver. You can achieve cm accuracy with this but it's probably.. but I don't have much details. As for your iPhone question any app that accesses the private API to access Wifi measurements will be rejected by the App store so you won't be able to publish anything that relies on Wifi. You can still use it for..
How to find the distance between two CG points? http://stackoverflow.com/questions/1906511/how-to-find-the-distance-between-two-cg-points out. If i have pinced in surely the new distance will be lesser and viceversa. But dont know how to find an accurate measurement for the distance between 2 points so that i can compare Anyone have an idea how to do this iphone cocoa touch share improve..
Measuring velocity via iPhone SDK http://stackoverflow.com/questions/1994018/measuring-velocity-via-iphone-sdk so via the CoreLocation API fairly easily but I am concerned about battery consumption since this is to be a real time measurement that could be used for up to a couple of hours at a time. My understanding is that while you are actively monitoring for.. prototype that uses the LocationManager API. It works OK but the update cycle is far from ideal for a real time measurement of velocity. Depending on circumstances it can take up to 4 5 seconds sometimes to update. Cruising at a given speed tends..
Detecting Acceleration in a car (iPhone Accelerometer) http://stackoverflow.com/questions/2733249/detecting-acceleration-in-a-car-iphone-accelerometer navigation systems combine a gyro and accelerometer. The reason you can't do this was given by Einstein Using a local measurement you can't distinguish between gravity and acceleration. You do have some useful non local information the assumption that..
Corelocation incorrect distances http://stackoverflow.com/questions/3093919/corelocation-incorrect-distances newLocation fromLocation CLLocation oldLocation test that the horizontal accuracy does not indicate an invalid measurement if newLocation.horizontalAccuracy 0 return NSLog @ accuracy d newLocation.horizontalAccuracy test the age of the location.. newLocation.horizontalAccuracy 0 return NSLog @ accuracy d newLocation.horizontalAccuracy test the age of the location measurement to determine if the measurement is cached in most cases you will not want to rely on cached measurements NSTimeInterval.. return NSLog @ accuracy d newLocation.horizontalAccuracy test the age of the location measurement to determine if the measurement is cached in most cases you will not want to rely on cached measurements NSTimeInterval locationAge newLocation.timestamp..
http://stackoverflow.com/questions/3515158/iphone-gps-accuracy or worse 2 With WiFi Internet I get a 80m horizontal accuracy. Is that normal What can I do to improve my coordinates measurement accuracy Thanks in advance for any help. iphone gps coordinates share improve this question From my experience you..
How do I measure the distance traveled by an iPhone using the accelerometer? http://stackoverflow.com/questions/3707726/how-do-i-measure-the-distance-traveled-by-an-iphone-using-the-accelerometer I want to measure a height of a box using an iPhone application. You'd start the application press a button to start measurement at the bottom of a box move your iPhone from to the top of the box then press a button to stop measurement. The application.. to start measurement at the bottom of a box move your iPhone from to the top of the box then press a button to stop measurement. The application would then calculate and display the height of the box. How would I use the accelerometer to perform this.. would then calculate and display the height of the box. How would I use the accelerometer to perform this kind of measurement iphone share improve this question Try photographing an object of a known size at the distance of interest. share..
An -observeValueForKeyPath:ofObject:change:context: message was received but not handled http://stackoverflow.com/questions/4120539/an-observevalueforkeypathofobjectchangecontext-message-was-received-but-not ' CGImage 0x276fc0 An observeValueForKeyPath ofObject change context message was received but not handled. Key path measurementDescriptor Observed object MeasurementPointer 0x8201640 entity MeasurementPointer id 0x8200410 x coredata EBEE0687 D67D 4B03.. entity MeasurementPointer id 0x8200410 x coredata EBEE0687 D67D 4B03 8C95 F4C60CFDC20F MeasurementPointer p75 data measurementDescriptor 0x260fd0 x coredata EBEE0687 D67D 4B03 8C95 F4C60CFDC20F MeasurementDescriptor p22 Change kind 1 new MeasurementDescriptor.. MeasurementDescriptor id 0x260fd0 x coredata EBEE0687 D67D 4B03 8C95 F4C60CFDC20F MeasurementDescriptor p22 data n measurementName Temperature n measurementUnits U00b0C n sortString nil n Context 0x0' Call stack at first throw 0 CoreFoundation 0x30897ed3..
iPhone - What does the gyroscope measures? Can I get an absolute degree measurement in all axis? http://stackoverflow.com/questions/5112536/iphone-what-does-the-gyroscope-measures-can-i-get-an-absolute-degree-measurem What does the gyroscope measures Can I get an absolute degree measurement in all axis I am relatively new to iPhone development and I am playing with the gyroscope using Core Motion. After a few.. thanks iphone core motion share improve this question The iPhone uses accelerometers for its internal angle measurements which means they are relative to the Earth's gravity. That's about as absolute as you're going to get unless you need this..
http://stackoverflow.com/questions/5541660/iphone-ipad-gyroscope What is the practical use of it iphone ipad gyroscope share improve this question An accelerometer is a direct measurement of orientation while a gyro is a measurement of the time rate of change of orientation. 1 By combing the output of the two.. gyroscope share improve this question An accelerometer is a direct measurement of orientation while a gyro is a measurement of the time rate of change of orientation. 1 By combing the output of the two sensors called sensor fusion one can determine..
Store orientation to an array - and compare http://stackoverflow.com/questions/6368618/store-orientation-to-an-array-and-compare Simply put don't and another reason not to . Can you use the accelerometer data instead An accelerometer is a direct measurement of orientation from the DCM manuscript and that is what you need. And as for tc's question does the orientation relative..
Need to find Distance using Gyro+Accelerometer http://stackoverflow.com/questions/6647314/need-to-find-distance-using-gyroaccelerometer dx vx dt and similarly for dy and dz. Here float acceleration_x n contains x acceleration values from start to end of measurement at times 0 dt 2 dt 3 dt ... n 1 dt. To find the total displacement you just do dl sqrt dx dx dy dy dz dz Gyroscope is not..
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