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Turning the tide on The Gap's darker side

Gap Park in Sydney, Australia extends for a couple of kilometres along the top of sheer rugged cliffs facing the Pacific Ocean. It is a public space with stunning views and an ecologically sensitive environment, but sadly also a place with a history of suicides, accidents and unexplained deaths. Feeling duty-bound to do something to preserve life and repair the park’s negative image Woollahra Municipal Council has implemented a master plan involving both deterrence and response measures which now include a Geutebrück GeViScope-based video security system.

Besides generating distressing duties for the police and other rescue services involved, the almost weekly self-harm-related incidents in Gap Park are personal tragedies for individuals, families and the community at large, which Woollahra Council felt it had to tackle. Consultation with mental health and crisis support agencies revealed that people considering suicide often spend several hours on the cliff tops before deciding one way or another. Active intervention during this period could be the key to saving some lives. With the aid of other stakeholders, experts and local residents, the Council devised a collaborative plan aimed at reducing incidents of self-harm and hence improving the area’s reputation and encouraging more visitors. The thinking was that if the number of tragedies could be reduced and the park de-stigmatised, then more visitors would come and this in turn would deter people who were seeking to do themselves harm.

Deterrence and response

Realising the best approach would be to include both deterrence and response measures, the Council identified the need for improvements at the entrances, more effective fencing to keep people out of danger zones, new seating and improved lighting and effective signage, as well as call points to provide support for individuals contemplating suicide or self-harm. It also needed a video surveillance system, one which would allow incidents to be identified and analysed round the clock to aid speedy police intervention.

For assistance in designing and implementing the project, the Council turned to Security Consultants International, and for integration and installation to Kings Security Systems. At first the Council’s tight budget only allowed for partial implementation of the CCTV design but federal funding has since enabled significant upgrading.

The first phase of work included restyling the park entries, the erection of inward curving fences along the cliff edge to deter climbing, the installation of new seating and low-level LED lighting to improve the ambience especially at night. This was accompanied by new signage and two purpose-built, vandal-resistant telephone help points with autodialing for the charity Lifeline and the emergency services, together with automatic audiovisual feeds and location ID.

With new signage came telephone help point with autodialing for charity Lifeline and the emergency services.

Recognising the location as a popular beauty spot and an environmentally sensitive site, the cameras were carefully sited to preserve views from nearby properties, and Kings Security used directional drilling to lay conduits without damaging the indigenous coastal vegetation.

Initially just four Bosch MIC 412 thermal PTZ cameras were installed to provide partial coverage of the site. With salt and weatherproof, vandal-resistant housings, these enabled vision at night and in bad weather, at considerable distance and amongst dense vegetation.

The phase 2 upgrade

In 2011, the original digital recorder was replaced by a GeViScopeHS/R with an expansion unit; the telephone help points were given their own dedicated fixed-view cameras; and five Moog ‘thermal & optical’ cameras were added to provide both thermal and optical views at the same time. This then enabled the re-location of other (Bosch) cameras for greater effect.

Gap Park VMD zones. Two virtual fence-lines enable reliable automatic detection of anyone in the danger zone.

The GeViScope is housed in a building adjoining the park which belongs to the New South Wales National Parks and Wildlife Service which shares management responsibility for the area. While one camera monitors this base station building, the others are concentrated near the north and south entrances and along the cliff-top walk. This arrangement enables monitoring centre operators to help with missing persons searches by identifying individuals as they enter or leave the park, and to find them if they remain anywhere in the park.

As far as the GeViScope is concerned, its short search times, intelligent bandwidth management, low latency and low bandwidth transmission for remote monitoring; as well as its openness for integration with third-party cameras and its facility for programming executable buttons and applications from the monitoring screen, are some of the reasons given by Daniel Paul, of Security Consultants International for choosing it for this project.

Real-time monitoring

Real-time video is monitored at a remote security monitoring centre. The operator’s role is to view the video and assess the situation only when requested to by the police following the report of a possible incident from a member of the public, an emergency call from a help point, or following an alert from Lifeline. The police utilise the video operator for help in determining where in the park assistance is required. The operator can also review recorded footage from the GeViScope for post-incident investigation but only in accordance with strict conditions and with specific permission from the Council.

Justine Henderson, communications manager and spokesperson for Woollahra Council reports. “We know the footage has been useful to police in responding to potential on site emergencies as we have seen an increase in use of the monitoring provided by the camera system. At the start of the project the footage was being used for retrospective investigations and now it is being used more for direct interventions – which is a good result.”

But the Council’s satisfaction is necessarily tempered with realism, “Of course we know we cannot hope to completely eliminate suicides at Gap Park, but we are committed to doing what we can and the reality is, response time is critical to successful intervention,” continues Henderson. And with future development in mind, recent technical activity has focused on the question of whether the GeViScope’s video motion detection capabilities could be employed to provide effective automatic real-time incident reporting.

Woollahra Mayor Isabelle Shapiro with Dr Gordon Parker, executive director Black Dog Institute and a supporter of the project.

Extended VMD trial

In autumn 2011, an extended trial was carried out using a selection of existing cameras to find out if the Geutebrück video analytics (VMD) could accurately identify dangerous incidents and provide a reliable basis for alerting the emergency services. It was argued that, to be of practical value, the system must not trigger alarms for irrelevant human incidents, or for lots of animal or bird-generated incidents. The level of acceptability was set at two nuisance or false alarms in any 12-hour period, in the belief that any more would probably result in the operator ignoring or responding poorly.

The testing focused on images provided by cameras at critical locations. The GeViScope’s VMD software was set up with two lines of alarm zones on each camera stream, one line following the fence and the other parallel to it on the seaward side. Using the many definable and variable rules which are available for customising this function, a time threshold was set for any target remaining within the first line of zones (intended to pick up someone climbing over the fence), and an alarm was set to trigger immediately if a target moved from the first line of zones into the second line of zones along the cliff edge.

The test results were very encouraging. During the trial period, the system correctly identified several incidents where individuals, or groups, breached the safety fence and ventured out to the cliff edge. Some people were clearly just making sightseeing or thrill-seeking explorations, but others seemed to have more troubled motivations. Thankfully, in all instances during the trial, even those who stayed in the danger zone for some considerable time eventually chose to return to safe ground. Happily too, the test also reported minimal false alarms which proved very easy for operators to recognise and disregard.

In the light of this successful testing, Woollahra Council will now seek funding to add a small number of fixed view cameras to the video system to establish a permanent analytic detection fence line. This option would be substantially cheaper than the original idea of using ground-based radar and would have the advantage of combining video display, detection and verification all in one. With some dedicated fixed view cameras taking care of these core functions, the existing PTZ cameras would then be available to provide the operator with a wider view, more accurate details etc., without risk of disturbing the VMD function.

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