Acoustic Triangulation Saves the Day
April 11, 2009
CIO Pakistan
James Beldock, CEO of ShotSpotter explains when we say that technology has no boundaries, it’s not just the business of transactions that we’re talking about. A merger of security and forensics, more companies are putting the challenge to how we use technology.
A few months ago, a US-based company named ShotSpotter came to Karachi to attend a local expo. After viewing the demo of their solution, the CIO Pakistan team was quite inspired to take a closer look at the element of security that was at play here.
“We essentially have a system which listens to the sound of gunfire or other loud explosive events such as IEDs (Improvised Explosive Device) and reports that location within a few seconds to the first responders, law enforcement agencies so that their response can be more efficient and effective,” starts of James Beldock, the CEO of the company.
How the ShotSpotter system works is really interesting. “It works on the principle of the acoustic triangulation. When somebody fires a gun, or makes another loud noise, the sound travels out from that location at the speed of, well, sound. It reaches each of our ShotSpotter sensors at a slightly different time depending on how far away they are from the original sound source. We use that slight difference in time of arrival to calculate the location and pinpoint it.” The accuracy of the system locates the origin of the sound to within 10 meters, as far as 1.5 to 2 kilometers from the sensors.
What is more interesting for a market like Pakistan is to gauge the kind of infrastructure readiness to adopt a solution like this. And it seems that the infrastructure is probably the biggest challenge for something like this to be deployed. “We are like many of those technologies dependent on some form of information transfer to take place between our sensors and our server appliance, which lives in the police facility or the defense facility where the actual shots are reported and recorded.” What perhaps makes Shotspotter powerful, is its flexibility. “We use everything from point-to point-radios, WiMAX, WIFI and cellular technology. And particularly in the US, we have even used telephone lines.” James laughs and comments, “Frankly I wouldn’t be surprised if we have to use strings and tin canes one day. Each city has its own approach. Certainly here in Karachi, it’s clear that WiMAX is going to be the solution. That is an embarrassment of riches in the US since most cities are not advanced enough to even have WiMAX.”
It’s all in the Similarities
James talks about the similarities in security challenges in countries like Pakistan and compares them to those he has observed in the US. “There is remarkable similarity between what I now know of Karachi’s public safety infrastructure and public safety challenges here and the challenges faced by many US cities. The reporting of gunfire by citizens may or may not be as good as the data possibly could be gathered by police forces and government officials.” In fact, he moves on, some cities in the US have as little as 11% of reported gunfire incidents, which means 89% of the cases go unreported. “Some cities are better. On average, about 30% of the gunfire gets reported to the authorities, which still leaves the majority of gunfire unreported. This means that one runs the risk, as a society of losing people.
If you don’t know about the incidents, you could have deaths of people who could have been saved if they had received help at the right time,” comments James.
The company is listed on the US department of Homeland Security authorized equipment list for ‘critical infrastructure protection’. This is a category of technology that can be used to protect critical infrastructure primarily to avert the risk of some form of disaster. “In the context of post disaster repair or post disaster security, we have rapidly mobile and rapidly deployable technology based on cellular sensors that is very important for security particularly the early phase of first responders who themselves may become the target of civil disturbances while they are attempting to help.”
There are really three uses of the ShotSpotter: the first is the obvious one which is that you respond or the police respond within seconds and know precisely where they are going not vaguely the neighborhood which is the normal situation. The second use is that the forensic provided of much higher level of fidelity and accuracy in analyzing what happened during an incident, down to how many gunmen were involved? How many weapons were fired? How many rounds were fired? Where was everybody standing? The third use is to profile an area over a long period of time, potentially years as we have in some cities in the US and one begins to build up a hotspot map, a map of areas that have under reporting of crime but in fact a very high level of gun crime or other types of explosions and that of course allows police and the government to apply resources more effectively.
For each one of those three uses of Shotspotter: immediate response, forensic analysis and long term trend analysis, there is different level of training required for the appropriate bodies with in government and police agencies. For example, dispatchers, the individual who vector police response within seconds of reports of crime, get one level of training. Detectives and other investigators get the second level of training and of course crime analysts and demographers get a third level of training and each one of those levels tie and function of the system.
The Technology
Shotspotter sensors run in an embedded digital signal processor DSP. “We are running bare-metal right down on the processor without an operating system and then we transmit data about each acoustic incident, we hear back via any one of a number of links. We are IP-enabled down of the sensor and the metadata about each acoustic incident is transmitted over a point-to-multipoint radio where the multipoint location is a base station. The base station then collects data from multiple sensors and there is a server of clients running a Windows Operating System Stack, that is Windows Server 2003 and SQL server as a backend. And then we have our server application, which gathers the data from multiple sensors, correlates the data across those multiple sensors and makes the calculation as to whether or not it should report the incident. We have full TCP/IP functionality between our server and clients. It is really the N-tier architecture in which the clients connect the server via anything from HTTP for thin client connections all the way up to TCP/IP non-firewalled connection for local dispatchers. We also have done such things like store and forward notifications, emails, SMS and even pushing data out to remote terminals living in helicopters or police vehicles over very thin connections as low as 19.2 Kbs, which is about the best bandwidth you can get in the helicopter without expensive radio equipment.
The topic of discussion, not surprisingly, doesn’t revolve around how good one environment is as opposed to another. What is worth focusing on is how readily available technology can be deployed to challenge the offerings that IT has to the proactive surveillance and security. As with any other field, if a solution can help make a system more efficient, than the return the solution will give you on your investment, will be tangible and real. The reality of the situation is that every town, village, city and country on the planet is plagued with problems. And where sensible solutions can be created to resolve and relieve some of the violence, it would be wise to make the adoption happen.
You can look up the company online at shotspotter.com and also contact their partners, ACS (acs-me.com) for Pakistan.
View article on ciopakistan.com
Erin Lopez |
|