Satellite navigation (SatNav) is a system which makes use of artificial satellites for providing autonomous geospatial positioning. In other words, satellite navigation systems can generate positioning information. Satellite navigation systems can also provide information regarding local time to high precision and can aid in time synchronization.
With the help of transmitted time signals and electronic receivers, satellite navigation can determine a specific location with high precision. However for accurately locating the position, a minimum of four satellites would be required. Electronic receivers make use of signals for analyzing the current local time to high precision. Satellite navigation capable of global coverage is called a global navigation satellite system. The electronic receiver analyzes the time and the distance from each of the satellites to reach the user's receiver antenna. The fourth satellite in the navigation system helps in removing the distance ambiguity involved in the case of three satellites. In fact, the more satellites involved in a satellite navigation system, the higher precision the accuracy that can be achieved.
Satellite navigation systems are more accurate than other navigation options. Being a broadcast system based on radio signals, an unlimited number of people can use it an unlimited number of times, regardless of location. Satellite navigation systems aid in air and sea traffic as well.
Drivers, of course, use SatNavs to plan and direct them on longer journeys. They are now also a major part of the UK Driving Test. Here are some other features of modern SatNav systems.
Speed camera location is now a standard feature on most satellite-navigation units – both aftermarket set-ups and those which are factory-fitted in brand new cars. Rather than reacting to radio waves, it uses Global Positioning System (GPS) to plot the bearings of fixed cameras, warns you when you are approaching one and reminds you of the correct speed.
More sophisticated 'directional' systems will alert you only to cameras on your side of the road, rather than all units nearby, to cut down on confusion.
Mapping data needs to be updated regularly via the sat-nav maker's website to keep abreast of the ever-changing UK camera network – a subscription is usually charged for this service.
The fastest route is not necessarily the prettiest. Picturesque alternatives are supplied by some manufacturers.
Alternatively, some devices, including high-spec Garmins and Navmans, allow you to choose a picture of a landmark you would like to see. The sat-nav then leads you to it. Location-tagged images can be viewed and selected on the companies' respective websites and saved to your system, ready for you to simply hit the picture and go.
GPS can also calculate this – far more accurately than most speedos, which typically over-read by about 10 per cent.
Traffic-avoidance systems predict the most likely routes taken by drivers to avoid jams and congestion, then considers all possible alternative side streets to calculate the least busy circuit around the snarl-up. Meanwhile, TomTom's IQ Route uses genuine average speeds which are based on data collected from drivers to calculate journey times. Travelling during rush hour or on a road that is scattered with traffic-calming measures, for example, will mean a dramatically lower speed than a 30mph posted limit.
Free real-time alerts about jams and roadworks are better than a crystal ball. They are available on units which incorporate Traffic Message Channel (TMC) or Radio Data System (RDS) receivers, such as the Becker Traffic Assist and Garmin nüvi, allowing you to re-plan your route. Trafficmaster roadside sensors play a big role, too.
Advanced sat-navs such as the TomTom Traffic series have the option of automatically navigating you around the obstruction. If your existing system doesn't have a TMC/RDS receiver, add-on devices are available for TomToms and Garmins from many retailers.
Virtually all GPS units on the market display POI data, such as the nearest petrol station, car park, hospital or cash machine, and many will also tell you about local hotels, restaurants and more. Some manufacturers even offer optional tourist guides, such as the Marco Polo series which is available from Garmin.
In addition, it's possible to download all sorts of useful information about the area you are travelling through.
Check the latest weather conditions at your destination by linking your sat-nav to the Internet via a Bluetooth wireless connection on your smartphone. Present technology does not allow for more involved Web browsing – but we are sure all that will change before too long!
Most GPS-enabled smartphones can lead you around the streets of many of the country's major towns and cities on foot when they're set to pedestrian mode. And so can vehicle units such as the Mio C220. Switching your satellite navigation to pedestrian mode means it will ignore one-way street restrictions and adjust the estimated time of arrival. Just check its out-of-the-car battery life first!
Now, where did I park? The Garmin nüvi 710 automatically makes a note of its position when you unclip it from the windscreen. So, take it with you when you leave the car and it will help you track down your vehicle in the most packed parking area. A smartphone with CoPilot GPS navigation software will also save your location – essential for returning holidaymakers when tackling the airport's long-stay car park.
A dashboard camera or simply dashcam, also known as car digital video recorder (car DVR), driving recorder, or event data recorder (EDR), is an onboard camera that continuously records the view through a vehicle's front windscreen and sometimes rear or other windows. Some dashcams include a camera to record the interior of the car in 360 degrees inside camera, usually in a ball form and can automatically send pictures and video using 4G.
EDRs and some dashcams also record acceleration/deceleration g-force, speed, steering angle, GPS data, etc.
A wide-angle 130, 170° or more front camera may be attached to the interior windscreen, to the rear-view mirror (clip on), or to the top of the dashboard, by suction cup or adhesive-tape mount. A rear camera is usually mounted in the rear window or in the registration plate, with a RCA video output to the display monitor/screen.
The resolution will determine the overall quality of the video. Full HD or 1080p (1920×1080) is standard for dash HD cams. Dash cameras may have 1080p, 1296p, 1440p, or higher definition for a front camera and 720p for a back camera and include f/1.8 aperture and night vision mode.
Dashcams can provide video evidence in the event of a road accident. When parked, dashcams can capture video and picture evidence if vandalism is detected by 360° parking monitor and send it to the owner usually employing 4G.