Skip navigation
All Places > Applications Prototype Lab > Blog > Author: temge-esristaff

Introduction

The most common technique for indoor location, determining an observer location inside an enclosed space, is the blue dot tracking approach. A client-side algorithm is actively tracking signals in its environment to determine the observer’s location in the context of the received signals. The types of received electronic signals can range from 802.11.x signals (WiFi, Bluetooth, etc.) to detecting magnetic anomalies. This method is considered an active client-side location approach.

A different method is to perform the positioning server side. The environment itself is configured to seek out surrounding signals and to correlate the matching signals from various points within the environment. This is a called a passive server-side approach.

We (the Applications Prototype Lab) wanted to explore the passive approach a little further as it allows for greater flexibility in the types of devices that can be recorded. Since no additional software needs to be installed on a device of interest, we can detect new hardware in our in-situ environment. However, since we must receive multiple recordings from our environment, a proper hardware layout is required to guarantee an adequate amount of coverage.

We do see potential for the server-based location services in the context of determining the digital footprint and traffic flow within a given location. For a business, this approach could be helpful for planning and design efforts as well as to provide on-demand information in contingency situations.

 

Prototype Layout

Here is the general strategy we implemented. The blue dot in the diagram represents a scanning device (blue box) actively seeking out signals. For this prototype we focused on detecting smart watches, wireless routers, cell phones, and laptops.

Detectable devices by wireless scanning

Using multiple blue boxes, we built out an environment keeping track of the signals in our office area. The blue boxes submit signals that are recorded by a central service in the cloud. In addition to providing a central collection service, the cloud service keeps us informed about the current state of the blue box hardware and provides a software update mechanism.

General layout of blue boxes and cloud service.

 

Hardware

In building our blue box prototype, we used a Raspberry Pi Zero W board running Raspian Jessie 4.9.24. The Zero hardware is nice as it already has a Bluetooth and WiFi chip onboard. Since we are using the onboard chip for communication with the cloud service, we need one more wireless adapter ( seen as the dongle) to act as the scanner module.

For simplicity, we distributed the blue boxes around our office area and kept them connected to a power outlet to get a continuous 24 hours data collection.

To give the blue boxes a spatial identity, we wrote an ArcGIS Runtime based application that allows us to place the blue box in the context of the building.

Closed blue box case.Blue box open with Raspberry Pi board exposed.

 

Methodology

When the Raspberry Pi starts up, it registers itself with the central cloud service. Upon registration, the blue box is assigned a unique identifier based on the MAC address, and client-side scripts ensure that the existing software is in sync with the version provided by the cloud environment.

After the initial handshake, the blue box assumes its scanning role and is ready to receive WiFi MAC addresses and record the RSSI (received signal strength indicator) for Bluetooth and WiFi devices. This information is sent to the cloud service from where we can use a trilateration algorithm to position the recorded signals. The location information is stored as a time-enabled point feature in ArcGIS Online.

 

Results

The screen capture below shows the distribution and the location of received signals. The blue dots are recorded Bluetooth signals and the amber colored dots are WiFi signals. The red squares show the location of the blue boxes in the context of the building with their associated unique identifier. Using the time awareness of the feature service, we can show the live data as a layer in ArcGIS Pro or in a web map.

Time enabled device collection visualized by ArcGIS Pro.Time enabled device collection visualized in ArcGIS Online.

 

We also developed an ArcGIS Pro Addin to view the archived content distribution by date and device type. We can see the start and the end of a work day as the numbers of devices increase throughout the day. Another interesting observation is the drop-off of Bluetooth devices during the nights and the weekends.

Analyzing archived data of collected devices by date and type in ArcGIS Pro.

Conclusion

We prototyped a server-based location service and we integrated our solution into ArcGIS Enterprise. For our blue box prototype, we used a low-cost hardware approach that has the potential to scale beyond our testing environment. We have written helper applications for the ArcGIS Runtime (iOS) and the ArcGIS Pro application to facilitate the setup and analysis of the recorded information. With the described approach, we see the potential for ubiquitous presence detection offering an indoor accuracy of about 8 – 20m / 24 – 60 ft.

Welcome to the Applications Prototype Lab’s new web demo page: https://apl.esri.com.

 

APL web demo landing page

 

Our new home page for web applications has an updated, fresh look that we hope is easier to navigate and explore. Discover demos by visually exploring the thumbnails and hovering over an item for more information or long-press on a touch screen device.

 

In the default Grid View, hover over a demo's name to get a short description. Hover over the thumbnail to view quick access linked to resources like a video, comments, source code, and other documentation. Click or tap the thumbnail to launch the application into a new tab.

Explanation of portal item links
Change to a List View with the icon in the upper right side of the page. In List View, resource information about the demo are shown next to the thumbnails. This is the view you can use to rate an application or share an application with social networking site or forward to a friend or colleague via email.

 

In both views, items can be filtered by a plain text search of an application's title, summary, or description or by one or more tags.  Clicking the "x" button will remove all filters. You can also sort filtered items by publication date, rating or author, by clicking the appropriate icons at the upper right hand corer of the view.

 

At present, there are more than 50 prototype applications for you to explore. Many of these applications have shared source code and accompanied demonstration videos. We encourage you to rate these apps, provide feedback and share socially. Esri employees and Esri distributors are also welcome! :-) You will be treated with access to a few extra applications that are either still in testing or have certain restrictions.

 

Enjoy and welcome again to the new Prototype Lab Portal.

Filter Blog

By date: By tag: