What was tested and how?
With the help of CHOICE’s testing outline and procedure, a number of aspects of GPS navigation were determined and listed. A procedure was initially designed in order to obtain efficient results for each aspect that is going to be tested. The results obtained throughout testing were compared to the new results achieved by CHOICE’s second testing of navigators.
The in-car performance of GPS car navigators and the smart phone will all be tested and were all divided into the following categories, along with how they were all tested.
Signal Strength/Reception- Signal strength and number of satellites was continuously observed throughout routes, in particular, in between high rise buildings and tunnels, bridges etc. More attention to this will be paid when carrying out the Sydney CBD route
All navigators displayed signal strength and reception using signal bars, along with particular voice instructions on some navigators that inform the driver if the signal is too low or lost. Some navigators also allowed us to view the number of satellites the device that achieved a fix on. This formed the basis of the testing and continuous observation was carried out while driving to see how signal strength alters in particular areas.
Accuracy of the following:Velocity- All GPS navigators displayed the speed at which the car is going. This was compared to the speedometer of the car.
The car was set on cruise control at the chosen speed limit of 60km/hr and any variances between the navigator speed and the car speedometer was calculated. For this reason, a suitable street was chosen with minimal traffic and no stops signs or roundabouts, such as a back street. Any interferences to the test such as the need to brake and the test was carried out again.
Time to arrive at destination - Target destinations were set on each navigator. A stopwatch was used as a separate timer and compared to the GPS timer with any differences calculated. Distance- Distance was calculated using the car’s odometer that was reset at the beginning of each test. This was then compared to the distance displayed on the navigator. Any differences were calculated and compared. Fastest route option and Shortest Distance option - a photo will be taken of the map of the route on both options to determine whether two different routes are provided or the same route is given for both options. TTFF (Time to first fix)-Throughout our testing, all navigators had to be tested under a hot start. The tests will involve placing the car in an area with a clear view of the sky and only moving the car just a few metres initially in order for satellites to calculate the direction and speed of the receiver. It will be timed to see how long it takes till a fix is set on the satellites.
Mapping and map database accuracy-Initially, the maps used on each navigator were investigated as to what their source is, for example, Sensis Whereis or Navteq. Accuracy- Investigations and observations were made into which specific areas had inaccuracies, such as roundabouts that exist but aren’t displayed on the map, instructions to turn left or right when it is illegal and so on.
Points of Interests (POIs):
Number of POIs- Each navigator will have a certain amount of POIs in their map database. The more POIs the better, assuming they are all accurate. Each was compared.
Symbols of POIs- The quality of symbols used for POIs will be commented upon to determine if the symbol clearly defines its title since many people rely on symbols to quickly determine the POI they need as the list can involve numerous titles.
Ease of Use
Data entry- This involves the ease of use of the keyboard and other buttons along with the searching of addresses and the time taken for internal databases to load the address.
Map and route display- It is vital that a GPS navigator displays the route clearly along with other map features. It is also a form of operational safety. The quality of maps and clarity of route display will be assessed in terms of scores and comments.
Installation- Installation of navigators will be investigated in terms of whether all navigators are installed the same way, whether they all mount of the windscreen in the same manner and the position of internal and external antennas once installed.
Screen glare- On a sunny day, the screen may be difficult to view; therefore each navigator was placed in a position where sun caused excessive glare on a navigator. Photos were taken of each screen in order to assist in the analysis of screen clarity.
Map and route display- As mentioned above, this was also tested due to the fact that if an image or route is hard to observe, it can cause a distraction for many drivers attempting to observe the route. However, in this instance, clarity and quality were also tested with the zoom functions present on numerous navigators and whether they vary or not.
Various voice instructions and clarity of sound- The speakers used to provide the direct sound of voice instructions is vital so all drivers so that they can hear clear instructions. Some will be more difficult to hear than others. Also, the number of various voices to choose from is very important and a major request by consumers as many voices can be very disturbing and annoying.
Connection mount stability- The stability of the GPS mount is important whereby many navigators may suddenly disconnect of the windshield when driving over a speed hump, ditch etc. This has occurred through my own experience with navigators and was vital in assessment. Also, many will shake or vibrate due to the mount stability which can cause difficulty seeing the screen
Recent Features- The features aspect of GPS navigation plays a major role in comparison of navigators. Many people are only interested in what features each navigator has to offer, therefore, any new features were assessed in each navigator in terms of what each navigator has to offer.
Analysis of features– Many navigators include new features that others don’t have. They were also tested and experimented upon to determined whether they actually operate efficiently. This can include the detection of speed cameras, red light cameras, area speed limits and others.