Thermal Cameras used for Maritime First Responders can be used for a variety of needs and requirements. Although the primary needs for Security and Safety Professional might be to locate criminals, casualties and hazards in the water especially in total darkness, there are other obvious uses. Noting that thermal cameras measure the temperature differential between objects, in daytime or in the “dark of night”, location of personnel in or around the water can also be required and of great assistance in the presence of smoke, fog and fire. Thermal Cameras are now used by professionals in Law Enforcement, Commercial, Residential, Industrial, Firefighter, First Responder and Home Land Security. They are now considered to be an essential tool utilized in many first responder agencies. They are now used and accepted worldwide for Safety and Enforcement Searches. They are considered to be extremely powerful weapons that can be used by officers and emergency personnel in the fight against crime as well as identification during low light or lack of clear visibility conditions. The use of thermal cameras offers professionals a clear and obvious tactical and search advantage. A handheld or watercraft mounted thermal camera allows the observation and location of suspects, without revealing the officers’ location in total darkness, in water or through smoke, moderate fog, and behind foliage. Thermal Cameras also increase the likelihood of identification and capture of a suspect, improving the professional’s ability to track and collect important evidence, increasing the probability of locating injured or hidden casualties in a water accident as well as locating the source of high temperature and associated injured and increased danger.
Night Vision vs Thermal Cameras
The two figures below are representative of what is seen with night vision (Figure 1) and what is captured with a thermal imager (Figure 2). Figure 1 represents a typical night vision view of a park surrounded by trees and foliage. It is not apparent that there are any suspects in sight. Using a Thermal Camera designed for first responders, figure 2 demonstrates that someone is attempting to hide behind the foliage. If the “law enforcement team” had been using a thermal camera, the suspect would be apprehended. The use of the thermal camera offers an undeniable tactical advantage.
Figure 1 - Nightvision
Figure 2 - Thermal.
Understanding Thermal Cameras
The human eye uses reflected light to visualize and produce an image. Daylight cameras, night-vision devices, and the human eye all work on the same basic principle. When light energy reflects off of an object, our eyes receive that signal and produce the appropriate image. In darkness, or in fog, or in smoke, we are limited to the external light provided. If there isn’t enough light or the artificial light is not sufficient, we no longer see clearly or see at all. When using “night vision” devices, the available light is magnified to produce an image. These devices have range limitations especially in extremely low-light conditions. It becomes difficult to view or recognize an object or produce any contrast for the image we would like to find. The thermal contrast between an object and its surroundings is what Maritime and Safety Professionals are seeking.
Thermal cameras measure the reflected thermal energy and are not susceptible or responsive to daylight or artificial light. Maritime First Responder Cameras indicate temperature variations usually by a display of a sharp black and white contrast screen. By sensing this thermal energy and displaying it as black and white video, thermal cameras allow you to see things from farther away and with greater contrast than conventional visible-light cameras and night-vision technologies. As long as there is a temperature variation, within the resolution and sensitivity of the selected camera, the image will be displayed. The use of flashlights and high beam patrol lights, when the Safety and Security Officers might want to maintain their hidden position, is never necessary.
Search and Rescue
In the figure above, this Search and Rescue mission was successful based on the clear image from the thermal camera of for survivors in a Marine accident. The clarity of the personnel location is clear and concise. In pitch black conditions, the clear view below (figure 3) of personnel in danger, as well as other vessels available for assistance, become evident. This allows for a safe and positive rescue mission. The camera observing the hazard at hand was using a longer lens FOV (Field of View) with a larger pixel array. This feature may be used for all applications for Thermal Cameras but especially for water search and rescue operations and will be explained in the FOV section.
The Importance of a Thermal Camera - Coast Guard Service
Primary Maritime Uses
- See suspects, criminals, overboard personnel in total darkness
- See through smoke, dust, and light fog
- See through camouflage and foliage in any lighting conditions
- See farther in zero visibility
- Significantly improve safety and mobility for Crew & Personnel
- Find hidden or injured in Water Hazard or Fires
- Anti-Piracy Horizon View
- Monitor temperatures for preventative maintenance and condition monitoring of equipment
- Searching for a personnel in deep water
- Examining containers storing hazardous or flammable materials
- Locating the seat and spread of a fire
- Searching for casualties
- Ice Danger Detection
- Analyzing the effectiveness of attack
- Overhaul Systems
- Pre Qualification of Marine Hazards
- Detect and display the relevant temperatures of objects within the scene
- Moving swiftly in “Search and Rescue” of casualties
- Enhance Mission Effectiveness
- Maximize Operational Capability
- Improve Officer Safety
- Mooring at night
- Oil Spills
- Port Security
- Improve Overall Safety
Maritime/ Marine Safety
In Marine applications of safety and security, the images you may obtain in total darkness allow you to make consistent decisions for boat and crew safety as well as maintain understanding of personnel safety in critical situations. When operating close to shore at night or in adverse environments, a thermal camera allows the crew and patrol boat officers an awareness of their surroundings so they can navigate confidently and safely. In darkness, confidently knowing safe distances from pilings, docks, floating debris, or other boats riding at anchor will allow officers and security personnel to do their job efficiently. The two figures below are typical of visualizing the same structure, boat, with and without a thermal camera. In Figure 3, the lights and reflection from the bow high search beams are only visible. In Figure 4, the boat and two passengers are visible. That is quite an advantage for safety personnel as well as for the boat occupants.
Figure 3 - Nightvision
Figure 4 - Thermal.
Field of View - FOV
The FOV or “Field of View” is the area of the image that is measured and viewed on the imager screen. The lens has the greatest influence on the total view, but a larger pixel array (matrix) may provide greater detail of desired observed graphics. By choosing the appropriate lens with a specific pixel array, you are also determining the length of visual capability for the Imager.
The information below displays two columns and details the actual view of the thermal camera on the water as seen through the selected lens. These views are based on the Field of View of each lens chosen. The camera and lens choice allows you to observe a variety of details that would not be seen by visible light or magnified existing light (night vision). Please note the Distance, D, as specified in Meters for each lens.
There are numerous lenses available for thermal cameras. Below are a few of the most common options for maritime applications.
Lens B (8.6mmFL, 160:26deg FOV, 320:50 deg FOV, D=230m)
Lens C (18.6mmFL, 160:12deg FOV, 320:24 deg FOV, D=500m)
Lens D (35mmFL, 160:6.5deg FOV, 320:13 deg FOV, D=1000m)
Lens E (46mmFL, 160:5deg FOV, 320:10 deg FOV, D=1250m)
Features to consider when choosing a camera:
- Simple to operate
- Fast Power-up time
- Lens Selection
- Detector Size (Pixel Array)
- Digital Zoom
- Image Frequency
- Shuttered Viewfinder
- White Hot / Black Hot Selection
Detector resolution is based on the pixel array that each camera contains. Using larger pixel arrays, 320x240, (as well as the lens “Field of View” selected and any special electronics being added to the optical circuit), cameras can measure smaller targets at a longer distance that would be sharper and in greater detail. As the pixel array increase in size and the focal length is increased, changes in thermal visibility will be extended over a longer distance. Please see FOV, “Field of View” paragraph above. Given a fixed pixel array, the FOV will determine the detail and distance that objects will be displayed.
Digital Zoom is a technique used to enlarge, magnify, and possibly enhance the image that is being viewed. It is primarily used to increase the viewed image size. Unlike Optical Zoom, which uses a combination of built in lenses to change the field of view, digital zoom is accomplished electronically only. The digital zoom feature is available on many cameras and may be specified as 2X (two times), 4X(four times), or 8X(eight times). Digital Zoom may not increase quality or image resolution, but will increase image size and Field-of-View visibility.
Image Frequency is commonly referred to as the refresh rate or frame rate. In traditional Industrial, Commercial and Building Diagnostics applications, refresh rate or frame rate is the accepted frames per second update for the image being transmitted to the display. Rates are commonly listed as 9Hz or 30Hz. These convert to 9 frames or 30 frames per second. Higher frame rates are usually found on cameras with better resolution as well as cameras used for Professional “Firefighting’ and "Law Enforcement" applications involving motion. For Maritime use, either the 9 or 30 Hz is acceptable. If the application anticipates using a video output, a higher refresh rate is preferred. The choice is based on application and camera specifications. All Thermal Cameras with a frame rate above 9Hz are controlled for export by the US Department of Commerce and require appropriate paperwork.
There are two choices that you may have, depending on the camera and the application. Most traditional Thermal Cameras have an open eyepiece non-shuttered or visual display (similar to a digital camera) to view the thermal image. In Maritime First Responder uses, there may be many opportunities for officer safety and security, especially in the darkness. The open eyepiece, non-shuttered, would also radiate some visible light at the eyepiece. A shuttered eyepiece keeps light from coming out of the viewfinder and avoids alarming animals, suspects, criminals or other target subjects. The user is the only person who is able to see the image.
Maritime and Open Water Solutions
Thermal cameras that are part of the Professionals’ arsenal of tools to fight crime as well as save lives has become an essential component for Safety and Security in the Maritime First Responders life. For security and capability of successful search and rescue missions, it has become a required component of ship accessories. For complete product and application information, please contact us contact our Certified Maritime Thermal camera Experts to discuss your needs and options.
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