Glossary of terms
The index of specific terms in Detective Store
In this dictionary you will find concepts which are related, directly or indirectly, with detective equipment used for surveillance and countersurveillance, acquisition and protection of information and protection of property.
Dictionary is constantly expanded, so it consists of a complete set of definitions needed to understand articles, product descriptions, other information and technical specifications published in our online store.
- A/D converter - analog to digital; ADC – used to convert analogue signal (constant in time and values) to a digital representation (digital signal). First stage of the process is sampling – collection of signal values with a specific frequency (sample rate); afterwards the values are quantized – allocated with values from a definite set of possible values (converter's resolution is expressed in bits) and encoded in a binary form. It allows to record and process the signal by digital systems.
- Bluetooth – short-range wireless communication technology used to establish connections between a variety of electronic appliances such as keyboards, desktop and laptop computers, mobile phones, and others. Bluetooth is also used to connect mobile phones to induction loops.
- Breathalyzer calibration - a process of re-setting the reference data in order to ensure correct indication of breath alcohol content. More information can be found on the Breathalyzer calibration webpage.
- Breathalyzer sensor – a key element of a breathalyzer, responsible for measuring the breath alcohol content.
- Bug - colloquial term for a miniature listening device.
- Capsaicin - oleoresin capsicum, active substance of pepper sprays.
- Converter – a device used to convert one value to another according to a specifed dependence and with a specific accuracy.
- CCD (Charge Coupled Device) sensor – consists of numerous independent photosensitive elements, which record and allow to read out an electric signal proportional to the amount of light directed at the aforementioned elements. CCD sensors are quite common, being utilised e.g. in miniature cameras.
- CMOS sensor - Complementary Metal Oxide Semiconductor – a set of numerous photosensitive elements forming an integrated circuit; its elements are mainly digital, consisting of MOS transistors of opposing conductivity, connected so that in a set logical state only one of them is conducting. This type of sensor is present in the HD BU-13 camera.
- DAC (digital to analog converter, D/A) – an electronic system converting digital signals (usually a binary number in form of digital data) to analogue signal in form of electric current or voltage proportional to the number.
- Data compression – altering the recorded information in order to reduce redundancy, and in result the volume of the set. Basically, it expresses the same information with a smaller number of bits.
- Decompression – recreation of original data basing on their compressed form, with use of a decompression algorithm compatible with the compression algorithm. The decompression process is opposite to the compression process.
- Demodulation – a process opposite to modulation, allows to read carried information.
- DSP - (Digital Signal Processing) a branch of science and technology digital signals and methods of processing them. The main purposes of DSP are sound processing and compression, digital image compression, video encoding, speech processing and recognition, ane digital telecommunications.
- Dynamic range – a difference in volume between the quietest and the loudest sound in an audio signal. The value is displayed in dB. The dynamic range depends on resolution – the larger the resolution, the larger the dynamic range.
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- Firewall – a means of protection for networks and computer systems against intrusions and unauthorized data leaks. The term might refer to both dedicated hardware supplied with proper software, or to software alone installed e.g. on a home computer.
- Frequency response – frequency range in which signal damping has a value no higher than 3 dB (3 dB amplitude drop, compared to initial amplitude)
- Frequency scanners – advanced wideband RF receivers capable of utilising numerous types of modulation and equipped with an array of functionalities – noise reduction level adjustment, channel memory banks, auto-attunement to frequencies of strong signals, and much more.
- GPS - Global Positioning System – a navigation system of global range, using navigation satellites, created by the US Department of Defence; allows to establish coordinates and elevation with a 5m accuracy. Its operation is based on measuring the time the radio signal from the satellites takes to reach the receiver. Vehicle and personal trackers utilise this technology.
- GPS Cold Start - time required to retrieve data about constellation and technical state of satellites after a considerable time since switching the tracking device off. The best of GPS receivers are able to establish the location in less than one minute, though it might take longer with inadequate signal strength. Prolonged time is necessary to establish the current position of the satellites.
- GPS Hot Start – time required to retrieve data from a satellite after switching the receiver off for a short period of time, up to a couple dozen minutes, while cached information is still valid.
- HD - High Definition – digital multimedia format ensuring excellent quality and high image resolution. Images in this format are clear, sharp and detailed.
- HDMI - High Definition Multimedia Interface – a digital interface for audio/video signals, allowing to transfer a complete, uncompressed data stream; enables connecting any HDMI-compatible devices.
- Induction loop – an appliance utilising electromagnetic induction, enabling short-range wireless communication, e.g. between a mobile phone and a micro-earpiece.
- Integrated circuit - chip, die – a miniaturized electronic circuit consisting of from a couple to hundreds of millions of basic electronic componenst, such as transistors, diodes, resistors, or capacitors.
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- Keylogger – enables covert recording of everything typed on a keyboard; usually connected between the keyboard and the computer, or concealed within the keyboard.
- LCD (Liquid Crystal Display) – a display type based on altering the polarity of light resulting from changes in orientation of liquid crystal particles caused by an applied magnetic field.
- LED screen - known for their small weight and size (thickness), due to which they are frequently used in TV sets, computer monitors, or in handheld electronic devices.
- LED (Light Emitting Diode) – electroluminescent diode, an optoelectronic semiconductor device emitting radiation in the range of visible light, and in infrared and ultraviolet spectrum.
- Megapixel - Mpx, Mpix – a value related to the number of elementary points of a photosensitive matirx. One megapixel equals one million pixels.
- Modulation – purposeful alteration of signal parameters, allowing to carry information. The carrier is a sine wave; parameters that can be modulated are its frequency (FM frequency modulation), amplitude (AM amplitude modulation) or phase (PM phase modulation), as well as pulse modulations.
- Motion detector, motion sensor – a device designed to detect various types of movement by means of recording changes in frequencies received by the sensor caused by moving objects. The detection is equal to activation of a device upon detecting motion.
- MP3 - (MPEG-1/2 Audio Layer-3) – a standard of digital sound recording processed by a lossy compression algorithm. Currently it is the most popurlar audio file format, allowing to retain decent quality at a considerable degree of compression and small file size.
- Night vision device – allows to see in nocturnal conditions. Its main element is an image intensifier, capable of amplifying residual light a couple thousand times, thus allowing to user to see in very poor lighting conditions – even moonlight is sufficient. Certain devices allow to see in complete darkness, though they use additional illuminators, usually operating in infrared range.
- Noise – a sound with its spectrum balanced through the entire range, without any clearly distinguishable frequencies. White noise with completely flat characteristic has few practical application in acoustics, due to the manner of hearing and selectivity of human ear – this is why sounds of specifically selected frequencies are used. It can be useful e.g. to hide sounds of a conversation, to render it inaudible outside of a specific room.
- OLED (Organic Light-Emitting Diode) – an electroluminescent diode made from organic compounds; the term is also used to refer to a class of displays utilising this technology. They are simple to manufacture, allow to create flexible screens. OLEDs offer a wider range of reproduced colours and viewing angles than LCD panels, and are more energy efficient, as OLEDs require no additional backlight.
- Operating System – a piece of software administrating computer equipment, providing environment for running and control over users' tasks.
- PenDrive – frequently referred to as USB Flash Drive, Flash Disk, FlashDrive, Thumb Drive, Massive Storage Device, Flash Memory Stick Pen Drive, USB-Stick; a mobile device carrying built-in Flash EEPROM non-volatile memory, utilising a USB port to communicate with other devices; a Plug&Play device – requires no additional drivers or accessories, can be used straight after plugging to a USB port of a computer.
- PAL (Phase Alternating Line) – colour television image transmission standard. Created in 1967 as an improved modification of the NTSC system; frequently used for images consisting of 625 lines per frame, at 50 Hz refresh rate and 25 frames per second.
- Pixel - coinage of words picture and element; smallest uniform (showing a specific colour) element of a picture.
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- RCA - also known as Cinch – a connector named after Radio Corporation of America, who introduced it in the 1940s; very common in A/V devices. Utilises asymmetrical signals; prone to electromagnetic interference at longer distances, which can be reduced to a certain degree by using gold-plated connectors and high quality copper wires.
- Real-Time GPS – tracking of location of vehicles equipped with GPS receivers, conducted in real time. Usually performed by means of a dedicated Internet platform allowing to place data received from the GPS device (sent via mobile phone network) directly over a digital map, e.g. Google Maps. An example of such application can be tested on the Detective Store GPS website.
- Router – a networking device used to connect computer networks, acting as a communication node. Using the information contained in TCP/IP packets, it routes the packets from the source to target networks, being able to differentiate them among a number of networks connected to it.
- Resolution – a number of photosensitice elements installed in a photosensitive sensor. Each of the elements reflects one single point of the photographed object. Those smallest points reflected on a screen are called pixels. The number of pixels in digital cameras is expressed in megapixels (one million of pixels); currently manufactured devices usually employ 2 - 12 megapixel sensors.
- Screenshot - screen dump, screen capture – saving of the image currently displayed on a computer or mobile phone screen.
- SD - Secure Digital. SD cards are used as data storage by a variety of devices, from mobile phones and cameras to GPS transmitters.
- Surveillance – in general, a set of actions performed to track (monitor) people's behaviour.
- SMS - Short Messaging Service – a service allowing to send short text messages over mobile phone network.
- SpyLogger - a professional instrument enabling comprehensive monitoring of computer usage. Records everything that was typed on the keyboard, information about used programs, visited webpages, data filled in online forms, and takes screenshots at predefined intervals.
- SIM - Subscriber Identification Module – an electronic card with built-in memory and a miniature chip; SIM cards store information necessary for the mobile phone to function – it identifies the subscriber and stores a certain amount of data, e.g. the contact list.
- SIM - lock – a safety measure in a mobile phone's firmware, applied by the manufacturer at the service provider's request; usually rendering the phone unable to authorize SIM cards of other service providers.
- SQUELCH – adjustable noise reduction system, allows to define a signal threshold, exceeding which switches on a speaker, allowing to listen to the signal. This allows to avoid listening to ambient noise and interference, and to focus on proper signals alone.
- SNR - signal-to-noise ratio – a ratio of usable signal strength to noise in electronic appliances and telecommunication. Defines a ratio (in dB) of usable signal strength in a specific frequency band to noise strength in the same band.
- TTFF - Time To First Fix – time required for a GPS tracker to first establish its position after switching it on. Usually it takes about 1 minute; the higher the quality of the device, the shorter the time.
- USB - Universal Serial Bus – a common standard of connecting a variety of devices to computers.
- VGA - Video Graphics Array – one of standards for graphics, frequently referred to as TV quality, provides image in 640 × 480 resolution in 256 colours.
- VLAN - Virtual Local Area Network – allows to create self-contained logical networks within physical netword infrastructure.
- WLAN - Wireless Local Area Network – has a range of a dozen-odd meters to several kilometers and flow capacity up to 300Mb/s; allowing simultaneous two-way transmission.
- Wi-Fi – an IEEE 802.11 standard, established to create wireless computer networks, used for setting up local networks.
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