We commonly use GPS technology to navigate outdoors and find our way to a place or building. Although it is a relief to find the building we are looking for, oftentimes the hassle is not yet over. We still need to find the right entrances, ramps, elevators, or the office we are looking to visit. Since outdoor navigation techniques are not usable indoors due to the weakened reception, we are suddenly left in the dark – unless, we have access to an indoor mapping and navigation tool.
What is Indoor Mapping?
Indoor maps help us navigate inside buildings much like how outdoor maps help us outside a building. An indoor map is a digital visualization of the layout of a building or closed space.
Indoor maps are commonly obtained from CAD drawings such as floor plans and blueprints. Although they can also be drawn from scratch using a design studio interface. Indoor maps display indoor details such as hallways, walls, stairwells, elevators, doorways, and other indoor features.
They may even include human geography elements, like the name of who works in a particular office. You may commonly see them take the form of emergency plans or the layout of vendors on a convention floor.
How is indoor mapping different from outdoor mapping?
Indoor mapping and outdoor mapping are similar in many ways, as both involve creating a representation of physical space. However, there are several key differences between indoor and outdoor mapping:
- Scale: Indoor maps are typically much smaller in scale than outdoor maps, as they only represent the interior of a building. Outdoor maps, on the other hand, can cover entire cities, regions, or even countries.
- Accuracy: Indoor maps require a higher level of accuracy than outdoor maps, as the dimensions and layout of a building can have a significant impact on navigation and wayfinding. In contrast, outdoor maps can afford to have a lower level of accuracy, as there is usually more space for error.
- Signal Availability: Outdoor maps can often rely on GPS signals for navigation, while indoor maps must find alternative means of determining location and orientation, such as Wi-Fi, Bluetooth, or visual markers.
- Obstacles: Indoor maps must take into account the presence of walls, doors, and other obstacles that can obstruct navigation and affect the accuracy of location data. Outdoor maps typically only need to account for natural features, such as hills and rivers.
- Data Collection: Collecting data for indoor maps can be more challenging than collecting data for outdoor maps, as it typically requires specialized equipment and techniques, such as laser scanning or photogrammetry.
Indoor Positioning
An indoor map of a building provides the basis for pinpointing the location of objects or places inside that building. An Indoor Positioning System (IPS) is made up of several technologies working together to identify location information of objects or places inside a building.
Ultrasound, beacons, and even the earth’s magnetic field are some of the technologies used to identify locations in real-time.
An IPS can contain a variety of Internet of Things (IoT) devices and sensors, depending on the use case and requirements for a particular application.
In some systems, a barometer is used to identify the floor level by detecting the variances in air pressure.
| Technology | Description |
|---|---|
| Laser Scanning | Uses laser beams to measure the distance between the scanner and objects in a room to create a 3D point cloud. |
| Photogrammetry | Uses images taken from different angles to create a 3D model of a space. |
| Computer Vision | Uses cameras and algorithms to automatically recognize and map the structure and layout of a building. |
| Bluetooth Low Energy (BLE) Beacons | Small, low-power devices that can be placed throughout a building to provide location data. |
| Wi-Fi-based Indoor Positioning | Uses Wi-Fi signals to determine the location of a device inside a building. |
| Magnetic Positioning | Uses the Earth’s magnetic field to determine the location and orientation of a device. |
| Ultrasonic Positioning | Uses high-frequency sound waves to determine the location of a device. |
| Dead Reckoning | Uses sensors to track the movement and orientation of a device and estimate its position. |
| Visual Positioning | Uses computer vision and machine learning algorithms to analyze images from a device’s camera to determine its location. |
This table provides a summary of the technologies used for indoor mapping and positioning. The choice of technology will depend on the specific requirements and constraints of the project. Visual positioning is a relatively new technology that is gaining popularity due to its ability to provide accurate location data using only a device’s camera.
What is Indoor Navigation?
Indoor navigation shows the best route from one location to the other. Indoor navigation works in real-time, showing an object or person’s location as they move inside a building. It provides information on whether someone or something is on the right route that leads to a place they want to find in the building.
In order to do this, there is both hardware, and software working in tandem. Due to the time and expense involved in setting up an indoor mapping solution, they are best when they will be used in an area for a long time, as the setup and breakdown is expensive and time-consuming.
Positioning Technologies Used for Indoor Mapping
When indoors, outdoor positioning technologies like GPS are not useful anymore. The level of accuracy drops greatly due to very low signal strengths. A different technique is required to be able to accurately map the indoors and navigate effectively inside a building. Indoor positioning methods vary depending on the technology they use, such as radio frequencies, ultrasound, or the geomagnetic field of a building.
Want to learn more about how your phone knows where you are? Learn about where that blue dot comes from here.
Radio based Technologies
Most radio based indoor mapping techniques use a network of BLE (Bluetooth Low Energy) devices to map the indoor structure of a building and transmit navigation information. Bluetooth beacons installed at specific points in a building continuously transmit radio signals that contain information about their location. Portable devices that are within their vicinity can pick up the radio signals and use it to triangulate their location relative to the location of the Bluetooth beacons (transmitter).
Wifi Hotspots can also provide reference points that can be used to determine a device’s location indoors. Many indoor environments offer access to the internet via Wifi hotspots and if the location of hotspots is known then devices calculate the position relative to the Wifi hotspots that they can “see”. In this sensor signal strength is used as a proxy for distance from the visible Wifi hotspot. There is also work on a Wifi standard that will enable the devices to calculate “time of flight” which will drastically improve the level of accuracy!
Geomagnetic based Technologies
Every building has its own geomagnetic fingerprint resulting from of its interaction with the Earth’s geomagnetic field. This provides an already existing infrastructure that can be used for indoor navigation using the building’s geomagnetic field when it is mapped against its floor plan.
Ultrasound based Technologies
Ultrasound identifies a position by determining the distances of objects from known points. The distances are derived from measurements of the time it takes for the ultrasound signals to move between sensors. The location information of a mobile object is determined by multiple (tri)laterations of the ultrasound signals received from objects at known, fixed locations (transmitters). Unlike the techniques mentioned above that can achieve accuracies of up to a few metres, ultrasound can provide hyper-accurate indoor location information of just a few millimetres.
Choosing an Indoor Mapping Solution
Solutions for indoor mapping and navigation vary in complexity and cost. The right solution is the one that best serves the needs of an organization. A solution for guiding visitors will work differently and would require a lesser accuracy than one that monitors employees’ movements in high risk, or hazardous work places. There is no one size fits all indoor mapping solution for everyone’s needs. A choice should be made on the best solution depending on the mission requirements, level of accuracy needed, the budget, staff available, and any other reasons that fit your use case.
The Benefits of Indoor Mapping and Navigation
The benefits of indoor navigation vary from application to application. For general office applications, the most common use cases are guiding users through common areas, meeting rooms, and offices; or even just monitoring movements. But wait, there’s more:
Emergency Response and Security
In case of emergencies, indoor mapping and navigation solutions can quickly convey information to users about the nature of emergency where it has occurred. Real time updates can provide safe guidance to exits, and help prevent fatalities. Those who respond to emergencies i.e. fire fighters, or security personnel, can also move quickly by following the best route for accessing a particular point in a building.
Manufacturing
Indoor mapping solutions can help in monitoring activities in a production line. This creates an opportunity to identify ways for optimizing workflows, and minimizing inefficiencies. The safety of employees can also be boosted if they get an alarm when they get too close to dangerous zones.
Healthcare
In hospitals, indoor mapping solutions can help healthcare personnel to easily find equipment and storage rooms or other locations in a facility. Linking this information up to an active patient database can make for especially helpful interactive maps that help nurses and doctors be more prepared when they walk into a room. Overall, indoor navigation can enhance the staff’s ability to monitor patients’ movements, and makes it easier to respond to their calls more efficiently.
Transportation
Indoor mapping and navigation solutions can help passengers more easily find their way at train stations or airports. This includes finding the right gate for their flight, rest rooms, or cafeterias. Google has even taken to mapping some especially high traffic airports, like in Atlanta, Georgia.
Seamless Navigation Between Indoors and Outdoors
With GPS for the outdoors and indoor navigation for the indoors, we can now move seamlessly through unfamiliar neighbourhoods and right into a specific room or office inside a building. As more companies embrace the concept of smart offices, it is a possibility that soon majority of buildings will make use of indoor mapping and navigation solutions.
Want to hear more about the advances in indoor mapping? Join us for a podcast episode on exactly that!
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