Malsingmaps Forum

Hi,
I am currently doing an academic research project on Information Systems. Part of my project is to measure the accuracy or rather the performance of GPS in Singapore.

Here are some measurements that I will be taking:
1. Accuracy is the the linear offset between the actual position and position estimate, when available. That means the difference between, the location of GPS coordinates measured by the device called position estimate and the actual position of the vehicle.

2. Yield (0-100%) is the availability of GPS based on a given time period.

3. Time to first fix is the time for the GPS device to get a lock on to GPS satellites upon start of vehicle.

As there is no proper framework/methodology that I can find to use, I have to come out with my own based on my research so far. However I will need experts help like you guys to assist me in correcting my framework or recommend me the correct steps to take for my measurements.

Thanks all in advance for assisting.

I have come out with conceptual framework that consist of 5 steps to measure the accuracy of GPS in Singapore.

Step 1: Preparation and Planning for Data Collection
1.1 Preparation items needed: GPS with track logging feature (for my research i chose Nuvi 1350), In-Car Video Recorder, Car, Route Plan, Stop watch
1.2 To plan out the route to be driven to the exact lane that I will be driving on
1.3 In-Car video recorder time has to be sync with GPS so as to verify true position later on.

Step 2: Data Collection
2.1 To collect the data with co-driver.

Step 3: Data Processing and Validation
3.1 To extract all data from the GPS and to plot it into a mapping software (ArcGIS Free 60day trail)
3.2 Load in a 2010 Satellite imagery into ArcGIS
3.3 Plot the points from the video recordings and measure the difference from the X,Y position logged in GPS

Step 4: Findings and Analysis of data
4.1 Measurement of min,max and mean of Accuracy of GPS in Singapore
4.2 Measurement of yield, availability of GPS in Singapore
4.3 Measurement of time to first fix, fastest, slowest and average time.


Step 5: Conclusion of the Analysis
5.1 Base on all the findings I will have a conclusion and summary of the performance of the GPS in Singapore which will be used for my other part of my research.

Your title too generalized. Many factors determine accuracy of a particular GPS.

Pro vs consumer units, handheld vs vehicular, factory accuracy of selected unit ( inherent error as a whole ), assisted ( WAAS ) ?, external vs built in antenna ( consistent signal strength is important ), reference source to authenticate accuracy ...... lateral shift error / stretching error ...

Thanks, I will research more on the items which you had just said.