Magnetometer in the context of SQUID

A compass is a device that shows the cardinal directions used for navigation and geographic orientation. It typically consists of a magnetized needle or another element, such as a compass card or compass rose, that pivots to align itself with magnetic north. Other methods may be used, including gyroscopes, magnetometers, and GPS receivers.

Compasses often show angles in degrees: north corresponds to 0°, and the angles increase clockwise, so east is 90°, south is 180°, and west is 270°. These numbers allow the compass to show azimuths or bearings which are commonly stated in degrees. If local variation between magnetic north and true north is known, then direction of magnetic north also gives direction of true north.

A smartphone is a mobile device that combines the functionality of a traditional mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multimedia playback and streaming. Smartphones have built-in cameras, GPS navigation, and support for various communication methods, including voice calls, text messaging, and internet-based messaging apps. Smartphones are distinguished from older-design feature phones by their more advanced hardware capabilities and extensive mobile operating systems, access to the internet, business applications, mobile payments, and multimedia functionality, including music, video, gaming, radio, and television.

Smartphones typically feature metal–oxide–semiconductor (MOS) integrated circuit (IC) chips, various sensors, and support for multiple wireless communication protocols. Examples of smartphone sensors include accelerometers, barometers, gyroscopes, and magnetometers; they can be used by both pre-installed and third-party software to enhance functionality. Wireless communication standards supported by smartphones include Wi-Fi, Bluetooth, Hotspots and satellite navigation. By the mid-2020s, manufacturers began integrating satellite messaging and emergency services, expanding their utility in remote areas without reliable cellular coverage. Smartphones have largely replaced personal digital assistant (PDA) devices, handheld/palm-sized PCs, portable media players (PMP), point-and-shoot cameras, camcorders, and, to a lesser extent, handheld video game consoles, e-reader devices, pocket calculators, and GPS tracking units.

In 3D human-computer interaction, positional tracking, also called pose tracking, is a process that tracks the position and/or orientation of head-mounted displays, controllers, or other input devices within Euclidean space. Pose tracking is often referred to as 6DOF tracking, for the six degrees of freedom in which the objects are often tracked.

In some consumer GPS systems, orientation data is added additionally using magnetometers, which give partial orientation information, but not the full orientation that pose tracking provides.

A smartphone is a mobile device that combines the functionality of a traditional mobile phone with advanced computing capabilities. It typically has a touchscreen interface, allowing users to access a wide range of applications and services, such as web browsing, email, and social media, as well as multimedia playback and streaming. Smartphones have built-in cameras, GPS navigation, and support for various communication methods, including voice calls, text messaging, and internet-based messaging apps. Smartphones are distinguished from older-design feature phones by their more advanced hardware capabilities and extensive mobile operating systems, access to the internet, business applications, mobile payments, and multimedia functionality, including music, video, gaming, radio, and television.

Smartphones typically feature metal–oxide–semiconductor (MOS) integrated circuit (IC) chips, various sensors, and support for multiple wireless communication protocols. Examples of smartphone sensors include accelerometers, barometers, gyroscopes, and magnetometers; they can be used by both pre-installed and third-party software to enhance functionality. Wireless communication standards supported by smartphones include LTE, 5G NR, Wi-Fi, Bluetooth, and satellite navigation. By the mid-2020s, manufacturers began integrating satellite messaging and emergency services, expanding their utility in remote areas without reliable cellular coverage. Smartphones have largely replaced personal digital assistant (PDA) devices, handheld/palm-sized PCs, portable media players (PMP), point-and-shoot cameras, camcorders, and, to a lesser extent, handheld video game consoles, e-reader devices, pocket calculators, and GPS tracking units.

Vostok Station (Russian: станция Восток, romanized: stantsiya Vostok, IPA: [ˈstant͡sɨjə vɐˈstok], lit. 'station east') is a Russian research station in inland Princess Elizabeth Land, Antarctica. Founded by the Soviet Union in 1957, the station lies at the southern Pole of Cold, with the lowest reliably measured natural temperature on Earth of −89.2 °C (−128.6 °F; 184.0 K). Research includes ice core drilling and magnetometry. Vostok was named after Vostok, the lead ship of the First Russian Antarctic Expedition captained by Fabian von Bellingshausen. The Bellingshausen Station was named after this captain (the second ship, Mirny, captained by Mikhail Lazarev, became the namesake for Mirny Station).

An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the orientation of the body, using a combination of accelerometers, gyroscopes, and sometimes magnetometers. When the magnetometer is included, IMUs are referred to as IMMUs.

IMUs are typically used to maneuver modern vehicles including motorcycles, missiles, aircraft (an attitude and heading reference system), including uncrewed aerial vehicles (UAVs), among many others, and spacecraft, including satellites and landers. Recent developments allow for the production of IMU-enabled GPS devices; an IMU allows a GPS receiver to work when GPS-signals are unavailable, such as in tunnels, inside buildings, or when electronic interference is present.

Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, diamagnetic materials are repelled by magnetic fields and form induced magnetic fields in the direction opposite to that of the applied magnetic field. Paramagnetic materials include most chemical elements and some compounds; they have a relative magnetic permeability slightly greater than 1 (i.e., a small positive magnetic susceptibility) and hence are attracted to magnetic fields. The magnetic moment induced by the applied field is linear in the field strength and rather weak. It typically requires a sensitive analytical balance to detect the effect and modern measurements on paramagnetic materials are often conducted with a SQUID magnetometer.

Paramagnetism is due to the presence of unpaired electrons in the material, so most atoms with incompletely filled atomic orbitals are paramagnetic, although exceptions such as copper exist. Due to their spin, unpaired electrons have a magnetic dipole moment and act like tiny magnets. An external magnetic field causes the electrons' spins to align parallel to the field, causing a net attraction. Paramagnetic materials include aluminium, oxygen, titanium, and iron oxide (FeO). Therefore, a simple rule of thumb is used in chemistry to determine whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic: if all electrons in the particle are paired, then the substance made of this particle is diamagnetic; if it has unpaired electrons, then the substance is paramagnetic.

Magnetoencephalography (MEG) is a functional neuroimaging technique for mapping brain activity by recording magnetic fields produced by electrical currents occurring naturally in the brain, using very sensitive magnetometers. Arrays of SQUIDs (superconducting quantum interference devices) are currently the most common magnetometer, while the SERF (spin exchange relaxation-free) magnetometer is being investigated for future machines. Applications of MEG include basic research into perceptual and cognitive brain processes, localizing regions affected by pathology before surgical removal, determining the function of various parts of the brain, and neurofeedback. This can be applied in a clinical setting to find locations of abnormalities as well as in an experimental setting to simply measure brain activity.

An inertial navigation system (INS; also inertial guidance system, inertial instrument) is a navigation device that uses motion sensors (accelerometers), rotation sensors (gyroscopes) and a computer to continuously calculate by dead reckoning the position, the orientation, and the velocity (direction and speed of movement) of a moving object without the need for external references. Often the inertial sensors are supplemented by a barometric altimeter and sometimes by magnetic sensors (magnetometers) and/or speed measuring devices. INSs are used on mobile robots and on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft. Older INS systems generally used an inertial platform as their mounting point to the vehicle and the terms are sometimes considered synonymous.

Mariner 2 (Mariner-Venus 1962), an American space probe to Venus, was the first robotic space probe to report successfully from a planetary encounter. The first successful spacecraft in the NASA Mariner program, it was a simplified version of the Block I spacecraft of the Ranger program and an exact copy of Mariner 1. The missions of the Mariner 1 and 2 spacecraft are sometimes known as the Mariner R missions. Original plans called for the probes to be launched on the Atlas-Centaur, but serious developmental problems with that vehicle forced a switch to the much smaller Agena B second stage. As such, the design of the Mariner R vehicles was greatly simplified. Far less instrumentation was carried than on the Soviet Venera probes of this period—for example, forgoing a TV camera—as the Atlas-Agena B had only half as much lift capacity as the Soviet 8K78 booster. The Mariner 2 spacecraft was launched from Cape Canaveral on August 27, 1962, and passed as close as 34,773 km (21,607 mi) to Venus on December 14, 1962.

The Mariner probe consisted of a 100 cm (39 in) diameter hexagonal bus, to which solar panels, instrument booms, and antennas were attached. The scientific instruments on board the Mariner spacecraft were: two radiometers (one each for the microwave and infrared portions of the spectrum), a micrometeorite sensor, a solar plasma sensor, a charged particle sensor, and a magnetometer. These instruments were designed to measure the temperature distribution on the surface of Venus and to make basic measurements of Venus's atmosphere.

In an explosive, pyrotechnic device, or military munition, a fuse (or fuze) is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately. However, when being specific (and in particular in a military context), the term fuse describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term fuze is used when referring to a more sophisticated ignition device incorporating mechanical and/or electronic components, such as a proximity fuze for an M107 artillery shell, magnetic or acoustic fuze on a sea mine, spring-loaded grenade fuze, pencil detonator, or anti-handling device.

A vibrating-sample magnetometer (VSM) (also referred to as a Foner magnetometer/oscillation magnetometer) is a scientific instrument that measures magnetic properties based on Faraday’s Law of Induction. Simon Foner at MIT Lincoln Laboratory invented VSM in 1955 and reported it in 1959. Also it was mentioned by G.W. Van Oosterhout and by P.J Flanders in 1956. A sample is first placed in a constant magnetic field and if the sample is magnetic it will align its magnetization with the external field. The magnetic dipole moment of the sample creates a magnetic field that changes as a function of time as the sample is moved up and down. This is typically done through the use of a piezoelectric material. The alternating magnetic field induces an electric field in the pickup coils of the VSM. The current is proportional to the magnetization of the sample - the greater the induced current, the greater the magnetization. As a result, typically a hysteresis curve will be recorded and from there the magnetic properties of the sample can be deduced.

The idea of vibrating sample came from D. O. Smith's vibrating-coil magnetometer.

Crustal magnetism is the magnetic field of the crust of a planetary body. The crustal magnetism of Earth has been studied; in particular, various magnetic crustal anomalies have been studied. Two examples of crustal magnetic anomalies on Earth that have been studied in the Americas are the Brunswick magnetic anomaly (BMA) and East Coast magnetic anomaly (ECMA). Also, there can be a correlation between physical geological features and certain readings from crustal magnetism on Earth. Below the surface of the Earth, the crustal magnetism is lost because the temperature rises above the curie temperature of the materials producing the field.

On Mars, the crustal magnetic fields have been noted as affecting its ionosphere. (See also Atmosphere of Mars) The magnetic fields on Mars from its rocks and crust are thought to come from ferromagnetism and if the material is heated above its curie temperature the magnetic imprint is un-done. The Mars Global Surveyor (MGS) discovered magnetic stripes in the crust of Mars, especially in the Phaethontis and Eridania quadrangles (Terra Cimmeria and Terra Sirenum). The magnetometer on MGS discovered 100 km (62 mi) wide stripes of magnetized crust running roughly parallel for up to 2,000 kilometres (1,200 mi). These stripes alternate in polarity, with the north magnetic pole of one pointing up from the surface and the north magnetic pole of the next pointing down. When similar stripes were discovered on Earth in the 1960s, they were taken as evidence of plate tectonics. Researchers believe these magnetic stripes on Mars are evidence for a short, early period of plate tectonic activity. Only roughly half of Mars seems to have a crustal magnetic field; there are several possible explanations for this, such as that an internal dynamo only affected part of the planet, or that a body struck Mars in the past destroying the magnetism.

The compass is a magnetometer used for navigation and orientation that shows direction in regards to the geographic cardinal points. The structure of a compass consists of the compass rose, which displays the four main directions on it: East (E), South (S), West (W) and North (N). The angle increases in the clockwise position. North corresponds to 0°, so east is 90°, south is 180° and west is 270°.

The history of the compass started more than 2000 years ago during the Han dynasty (202 BC – 220 AD). The first compasses were made of lodestone, a naturally magnetized stone of iron, in Han dynasty China. It was called the "South Pointing Fish" and was used for land navigation by the mid-11th century during the Song dynasty (960–1279 AD). Shen Kuo provided the first explicit description of a magnetized needle in 1088 and Zhu Yu mentioned its use in maritime navigation in the text Pingzhou Table Talks, dated 1111–1117. Later compasses were made of iron needles, magnetized by striking them with a lodestone. Magnetized needles and compasses were first described in medieval Europe by the English theologian Alexander Neckam (1157–1217 AD). The first literary description of a compass in Western Europe was recorded in around 1190 and in the Islamic world 1232. Dry compasses begin appearing around 1269 in medieval Europe and 1300 in the medieval Islamic world. This was replaced in the early 20th century by the liquid-filled magnetic compass.