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Questions tagged [assisted-gps]

Assisted GPS uses on-the-ground servers to retrieve satellite ephemeris information thus improving time-to-first-fix (location).

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2answers
46 views

Calculation between Raw GPS data to latitude,longitude points?

I am working on the GPS related project. The objective is to understand the calculation process of the raw GPS data (server side calculation). It means " How did we get the latitude and the longitude ...
4
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2answers
2k views

GNSS raw measurements on Android: Does real time/post processing Differential techniques possible?

In the recent months we all saw kind of breakthrough in Android Smartphone GNSS receivers: GNSS raw measurements are now accessible, and this is significant since those are the most common form of ...
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1answer
893 views

RTKGPS+ or RTKLIB configuration of rover and input streams for Stonex S8plus

I've tried to use RTKGPS+ and RTKLIB with external antenna and via NTRIP to communicate with Continuously Operating Reference Station (CORS) of my country (MAKPOS), but I couldn't make connection (i ...
3
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0answers
920 views

Height above sea level measurement

I would like to use height above sea level in the gravity equations. What is the source for getting it? Can i use altitude measurements from Altimeter or GPS 'z' measurement? For your kind information,...
2
votes
0answers
40 views

GPS accuracy for blind person O&M

I would like to be able to use GPS on my phone, in conjunction with an app, to enable O&M (Orientation and Mobility) support, on my device. I want the app to tell a blind person walking along a ...
3
votes
2answers
357 views

Why is the altitude information of the geotag from a drone/uav/uas/rpas (Phantom 3) so innaccurate?

I have a Phantom 3 4k and on examination of the geotag information the altitude reading is often inaccurate by 10-15 metres. Why is this? Is it because the drone only has a GPS rather than a DGPS unit?...
1
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1answer
876 views

Calculating radius of curvature and banking angle when set of lat, long and elevation are given?

I have set of lat,long and elevation values with me. Can you help me find the Radius of curve and banking angle. Formulae may be provided as an answer.
3
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2answers
791 views

Areas where DGPS with post processing (not RTK) is still required

I am wondering in which domains or countries where Differential GPS (DGPS) with post processing (not Real Time Kinematic [RTK]) is still required? It's known that RTK has been rapidly adopted by ...
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0answers
53 views

How to tell if a device supports Assisted GPS, and if how to get the Assisted GPS cooridinates?

1) Is Assisted GPS implemented at the hardware and OS level, or is it a hardware and secondary software thing. I've never used this so wondering what is required to 'access' this. I noticed a wiki ...
2
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0answers
352 views

Mmodify GPS tracker to accept two nmea inputs and gpsmarker to include a heading vector?

I use QGIS on a research vessel and wonder whether I could modify the QGIS 1.8.0 gpsinformation widget. I want to achieve two things. Change the GPS marker to a boat shape which points in the ...
5
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0answers
649 views

Translate Orientation from Sensor data to Geo location

I am tracking a device that might loose GPS signal then and there. And when the GPS signal is too low, I should use the accelerometer and Gyroscope sensors data to guess which way they should have ...
6
votes
4answers
2k views

Tracking a vehicle without GPS device

We are planning to write an application which have to track the user driving in his truck in the cities like New York city accurate upto which lane he was driving on. In the cities with those tall ...
13
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3answers
1k views

GPS Elephant Tracking: Utilizing A-GPS, WAAS, DGPS and Understanding HDOP, NSAT, and ZDA

*I'm using a GPS data logger (qstarz bt-q1000xt) to track the movement of zoo elephants, and I have a variety of technical questions. I've had limited success receiving answers from the vendor. You ...
3
votes
0answers
678 views

How to read a .GPB file in C#?

I have a .GPB file, I need to extract the common GPS data from it but I don't find a clear structure that specify the contents of that file. as a sample record from file 00000260 02 11 A9 61 E7 96 ...
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7answers
4k views

Why don't they use cell towers like GPS satellites?

If my understanding is correct, a GPS satellite produces a pretty simple signal which is basically composed of its location and its time. Given 4 of these signals, then one can uniquely solve for the ...
26
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6answers
14k views

How correct is the “Accuracy” value given by GPS devices?

I have a Garmin Forerunner 305 and a Google Nexus One Android phone. From the GPS on both these devices I can get a "Accuracy" value that is usually between 6-20 meters. How much can I trust this ...