Your Complete Guide to Urban Surveillance Gear
Today, covert video surveillance systems are available that are specifically designed for urban field surveillance. These systems allow law enforcement professionals to get "eyes-on" without raising red flags and provides an easy way to surveil important leads without having to sideline other active investigations. Covert video systems are available in a variety of undetectable disguises and offer a wide range of advanced features — up to and including real-time wireless world-wide monitoring. Over the past 20 years, Supercircuits has developed a complete line of ready-made urban field surveillance systems comprised of perfectly matched components. For many agencies, these ready-made systems present an affordable, effective and easy-to-deploy solution. Other agencies would rather just purchase key components and build their own. My goal is to make sure you find exactly what you need. Below, I'll present my recommendations for very best gear for urban surveillance, and will provide tips along the way to help you avoid potential pitfalls. Cameras The first and most important feature to consider in a camera for urban surveillance is its low light capability. This is determined by three key features: the camera's lux rating, its ability to see in the IR spectrum, and its signal to noise ratio. As you will see, there are many other things to consider to get the perfect solution. Lux Rating The lower the lux rating, the better the camera will see in low light conditions. For example, a camera with a 0.05 lux is far better for low light than say a camera with a 0.5 lux rating. Currently, there are cameras on the market that can see in almost complete darkness, with a lux rating of just 0.0001. An example of this is the Supercircuits PC164CEX-2.
IR Sensitivity (black & white) When a low lux rating is not enough, infrared lighting can provide additional illumination. However, cameras must be capable of seeing this frequency of light. Most color cameras can't see infrared illumination, and those that can do not very well. Because of this, most users have opted for low light b&w cameras, as they have no infrared filter and are very effective with IR illumination. IR Sensitivity (day/night) Another effective camera option for low light operations is day/night. Day/night cameras provide vibrant color during the day (helping to identify unknown suspects) and then switch to b&w mode at night — typically IR sensitive.
Please note, not all day/night cameras are created equal — as non-IR sensitive cameras offer no significant increase in low light ability. Always check with the cameras specifications or ask a consultant to be sure a given camera has the right features. Signal to Noise Ratio On the surface, many cameras on the market seem to have the same low light capability because their lux ratings are equal. What most people don't know is that the lower amount of light a camera is subjected to, the more noise will be visible in the video. A given camera may very well have a low lux rating, but if its signal to noise ratio is poor, the net result will be unusable video. Signal to noise ratio is expressed in decibels. Average cameras will have a 48dB S/N rating. Cameras will suited for lower light operations will have dB ratings at 50, 52 or higher. A camera we recommend for such applications is the PC164CEX-2 super low light b/w video security camera . Mounting In some concealments, there is little choice as to how the camera can be mounted. In others, there may be a lot of space for multi-positioning, and even windows for the camera to peer out of. When there is ample space you should consider using a mounting bracket with a ball joint — such as the Supercircuits MB14 universal mounting bracket, or in the case of micro cameras, the Supercircuits ENC-UNI. Lenses Lenses are the true governor of capabilities for any video surveillance application, and are unfortunately the most overlooked of any component. Consider the following when selecting the right lens: Pinhole Lenses Pinhole lenses are typically the most effective option when there is any chance that suspects will be in close proximity to the system. Because most materials used to disguise urban surveillance systems will be relatively thick, conical shaped pinhole lenses are normally the best choice. When installed properly, conical shaped lenses require only 1/16th inch hole in order to get a complete unobstructed field of view. In many cases, such a small hole will maintain concealment even when suspects are just feet away. Micro Lenses Whenever suspects will be a greater distance away (20 ft or more), micro lenses make a great option. With a diameter of just ½ in, micro lenses easily blend into their encasement and/or surroundings. Despite their small size, they even provide telephoto capabilities for applications requiring more detail. For example, a 25 mm lens viewing an area from 50' will provide a tight shot of 9.6 ft horizontally. Available focal lengths are 2.5, 3.6, 4.3, 6, 8, 12, 16 and 25 mm. CS-Mount Lenses CS-Mount lenses provide even greater telephoto capabilities, and are available with focal lengths up to 11,000 mm. However, CS-Mount lenses have higher f-stops, which limit how much light can pass through to the camera. As a result, the combination could render the camera unable to see in low light conditions. When selecting a CS-Mount lens, always inquire about the f-stop rating. Lenses with a f-stop rating of f1.4 or lower will be well suited for low light operations.
Infrared Illumination (IR) If IR illumination will be used, IR ready lenses are recommend. Almost all lenses will pass infrared light to the camera, but IR Ready lenses will pass a greater amount so that you can make the most out of the available illumination. Infrared Illumination Frequency Nearly every illuminator on market will have a tag line to the effect of "invisible illumination", but many users will report that they can see either a red glow or red dots coming from the Illuminator. What users are seeing is IR illumination — at either 750 nm or 880 nm. Those frequencies are close enough to lighting that the human eye can detect … we see those dots at the source, but the light emitted towards the target is truly invisible. This experience is quite acceptable for most security applications, but for covert surveillance those little red dots can completely undermine an investigation. A frequency of 940 nm or above which will provide completely invisible light, both from emission and source. Concealment In order for IR illuminators to work as desired, they need to have an unobstructed line of sight to the area. During low light hours, concealment of illuminators is mostly a non issue. During hours of sunlight, however, this need to have them exposed can become a potential issue. The best advice is to position IR illuminators up high — where most people don't bother to look, ideally in a shaded area, or around an existing fixture to help minimize any attention. At minimum, place illuminators in a location separate from other surveillance gear so if discovered, their true purpose may remain a mystery. Power Those who have used IR illuminators can attest they are amp hogs — and rightfully so, you'll want them disengaged when you don't need them. To conserve power, select IR illuminators with built-in photocells that will engage the illuminators only during low light conditions. For existing IR illuminators that don't have this feature, you can purchase and deploy off-theshelf photocells to provide the power saving feature. Wireless Transmission Concealment It's an absolute myth that wireless devices must have line of sight between the transmitter and receiver. However, different materials in between the transmitter and receiver will have varying effects on wireless range. When choosing concealment housings and materials, sticking with plastics and woods which are largely RF transparent shouldn't have any noticeable effect on range. If using metal is a requirement, you will likely need to place the transmitter antenna outside the enclosure in order to achieve desired performance. Cooling Most wireless transmitters on the market are built for indefinite operations, with only minimal concerns about cooling. Given the specific industry we are in, there are inexpensive
transmitters that have been basically stripped down of ancillary features such as cooling in order to meet size requirements in body-worn or temporary applications. On that note, always inquire as to whether or not the transmitter is designed for indefinite operation. RF Detection Anytime you send a wireless signal it can increase the risk of detection — as some savvy crooks will patrol the airwaves. An easy and inexpensive way to minimize risk is to use a low power transmitter that gives you just the range you need. To help further reduce concerns of detection, use a digital wireless transmitter. Additionally, digital wireless devices will minimize signal interference, and many digital transmitters will accept encryption modules for complete security. Interference Going the distance with wireless in urban environments can be tough. Not only do you have obstructions to contend with, but now that Wi-Fi 802.11 b&g is prolific, you also have interference which can often be the limiting factor. To skirt this problem, there are a couple of things you can do. First, if you are using more affordable analog devices, go with 5.8 GHz which is still a relatively uncrowded frequency range. Digital units will minimize signal interference, offer multiple frequencies to choose from, and perform better around obstructions. Range In order to get more range in urban environments, using a high gain antenna and/or a wireless repeater is always helpful. As a rule of thumb, high gain antennas will take a weak signal and make it a very clear signal — in most cases. Repeaters can be placed at junctures in the wireless transmission path — to hop over large obstructions such as tall buildings or just to get around a corner. Repeaters are made up of simply another transmitter and receiver set on different frequencies. With this in mind it is quite easy to build your own repeater, but ready-made units are available for your convenience. Unlimited Range Yes, it is possible … at least in urban environments. Now there are devices available that can transmit video, audio and data over CDMA networks (Sprint & Verizon). One example is the Supercircuits DVRM6W wireless advanced 4 channel digital video recorder , which is a rugged 4 channel DVR with built-in CDMA transmission. The DVRM6W DVR records super high res images on board and transmits usable low bandwidth images over CDMA. The DVRM6W is also ideal for remotely manipulating Pan/Tilt/Zoom cameras and IR illuminators. With the DVRM6W, you can view remotely from anywhere in the world via a simple internet connection. Recorders Micro DVRs For smaller, temporary slap n' go operations, micro DVRs are a must. Micro DVRs are just that … micro … so they take up very little space. And because they use solid state media, they draw very little power.
To add even more run and record time, sensor and relays can be used to turn them on and off. Any micro DVR with the power-up record feature such as the Supercircuits MDVR14 will be compatible with sensors & relays. Mobile DVRs For larger and longer term operations, mobile DVRs are highly recommended. Many of the features designed for in-car use make mobile DVRs ideal for urban surveillance use as well. Common mobile DVRs offer multi-camera inputs (4), alarm inputs for triggering, power-up recording, pre-event recording, heat resistance and Ethernet ports for remote connection via Wi-Fi. Evidence Retrieval For most DVRs on the market, you will need to go on site or in the area of operation to retrieve the evidence. However, the DVRM6 eliminates this need. With the CDMA connection of the DVRM6, evidence can be downloaded remotely from anywhere in the world. Sensors There are two primary reasons to use sensors — to save battery power and to receive remote notification of activity. Managing Power To manage your system's battery power, ideal sensors are PIR (Passive Infrared), magnetic (vehicle detection), beam break sensors and seismic sensors. While these devices need to be powered continuously, they require miniscule amounts of amperage. When used in conjunction with relays, you can turn power on and off to your IR illuminators, cameras, transmitters, DVRs, or any other device. One point of caution when using these devices … be sure to place them at points ahead of cameras and recorders. Let me explain. Say, for instance, there is an illegal dump site at the end of a alley. Sensors should be placed at the beginning of that alley, and cameras/recorders should be placed at the end, where the action of interest will take place. This will allow enough time for your cameras to engage and your DVR to boot up and start recording. Note: most DVRs will need 20 to 30 seconds. Notification DVRs designed for field surveillance (such as DVRM6) will offer a built-in motion detection feature. Paired with a CDMA connection, the DVR can then send automated activity alerts directly to you via SMS or Email. The DVRM6 is also compatible with advanced video analytic devices that can be programmed to discern between activities. As an example, cars driving by will be ignored but a car stopping to loiter will trigger an alert. Additionally, objects can be tagged, and if they are removed longer than five seconds, an alert will be sent. There are many ways to configure video analytics to pinpoint activity and reduce false alarms. Audio Audio is almost never considered for urban surveillance, due to the primary need of video and the thought the microphone will not be sensitive enough to penetrate disguises. However, sensitive microphones such as the Supercircuits PA3 are proven to be very effective — even inside most enclosures — so long as there are isolated sounds in the area.
Having a microphone is always a good idea, as you'll never know when the suspect may use a name or discuss important details at the scene of the crime. Power AC Power Whenever possible, a great luxury is to use AC to power your system, as AC power will keep your gear running indefinitely. Keeping it concealed, however, can sometimes be difficult. In these cases, I recommend that you utilize enclosures that appear to belong in the environment, or that would naturally be connected to AC power. I also recommend a small UPS placed inside of the disguise as a cheap form of insurance to provide back-up power during natural power outages, or when the power is intentionally disabled. Lithium Batteries For the slap n' go application, or sometimes the toss n' go disguise, AC power is simply not an option. These disguises are usually very small, so you'll need a battery with the very best in size to power ratio for ultimate effectiveness. I recommend a lithium battery, such as the Supercircuits MVLBCS-7 12v lithium ion rechargeable battery . To give you an idea of run time that you can expect, the MVLBCS7 will typically power both a camera and micro DVR for 9 to 11 hours. SLA Batteries Of course, the larger the concealment the more space you'll have for battery power — and consequently a longer run-time. For larger disguises the battery type of choice is called SLA (Sealed Lead Acid). SLA batteries are inexpensive, resistant to heat & cold and have a long shelf life. Whatever battery you choose, I always recommend purchasing two sets. While one set is in use, the other can be charging which makes refreshing power a synch. Installation Tips Monitors Today's surveillance gear will maintain its settings even when power is removed — up to 30 days for most devices. With this in mind, it's always best to perform all critical settings in the comfort of your office, which will significantly reduce installation time. However, it's often impossible to prepare for the positioning of the camera remotely. For that reason, it's best to include a small monitor inside the disguise — not only for camera positioning, but also to perform onsite evidence review when necessary. A perfect monitor option for smaller disguises is the Supercircuits MON1. The MON1 cups the eye which eliminates signatures at night and keeps the sun out during the day. Adhesives For the slap n' go concealments, I recommend using Velcro as an adhesive, as it is designed specifically for porous surfaces such as brick and concrete. Thanks for reading — I certainly hope this article has helped to clarify some of the options available for your Urban Field Surveillance applications. http://www.supercircuits.com