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Pacing (surveying)
Pacing is a reasonably easy and quick method of measuring distance in the field. It is used to measure a distance and is often used with a sighting or a hand compass. Most commonly, pacing is split up into segments, such as chains, which are set measures of distance. By determining one's own pace, distance can easily be estimated. Applications Common uses of pacing consist of measuring tree height or measuring the distance between plots. Pacing saves time but is not as accurate as using a tape measure and can be affected by terrain such as steep slopes, rocky areas, streams, and thick brush. A common practice in pacing when an obstacle is encountered is to offset or pace around the obstacle. However, sometimes pacing around an obstacle is not always an option. Good pacing can only be accomplished by practice. Knowing the distance of one's pace will help to ensure accuracy and precision of pacing distances. Other uses Pacing can also be used with a map. In the field, pacing can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Measurement
Length measurement, distance measurement, or range measurement (ranging) refers to the many ways in which length, distance, or range can be measured. The most commonly used approaches are the rulers, followed by transit-time methods and the interferometer methods based upon the speed of light. For objects such as crystals and diffraction gratings, diffraction is used with X-rays and electron beams. Measurement techniques for three-dimensional structures very small in every dimension use specialized instruments such as ion microscopy coupled with intensive computer modeling. Standard rulers The ruler the simplest kind of length measurement tool: lengths are defined by printed marks or engravings on a stick. The metre was initially defined using a ruler before more accurate methods became available. Gauge blocks are a common method for precise measurement or calibration of measurement tools. For small or microscopic objects, microphotography where the length is calibrated us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hand Compass
A hand compass (also hand bearing compass or sighting compass) is a compact magnetic compass capable of one-hand use and fitted with a sighting device to record a precise bearing or azimuth to a given target or to determine a location. Hand or sighting compasses include instruments with simple notch-and-post alignment ("gunsights"), prismatic sights, direct or lensatic sights, and mirror/vee (reflected-image) sights. With the additional precision offered by the sighting arrangement, and depending upon construction, sighting compasses provide increased accuracy when measuring precise bearings to an objective. The term ''hand compass'' is used by some in the forestry and surveying professions to refer to a certain type of hand compass optimized for use in those fields, also known as a forester or cruiser compass. A ''hand compass'' may also include the various one-hand or 'pocket' versions of the surveyor's or geologist's transit. History and use While small portable compass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain (unit)
The chain is a unit of length equal to 66 feet (22 yards). It is subdivided into 100 links (PDF) or 4 rods. There are 10 chains in a furlong, and 80 chains in one statute mile. In metric terms, it is 20.1168 m long. By extension, chainage (running distance) is the distance along a curved or straight survey line from a fixed commencing point, as given by an odometer. The chain has been used for several centuries in England and in some other countries influenced by English practice. In the United Kingdom, there were 80 chains to the mile, but until the early nineteenth century the Scottish and Irish customary miles were longer than the statute mile; consequently a Scots chain was about 74 (imperial) feet, an Irish chain 84 feet. These longer chains became obsolete following the adoption of the imperial system of units in 1824. Definition The UK statute chain is 22 yards, which is . This unit is a statute measure in the United Kingdom, defined in the Weights and Measures Act 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tape Measure
A tape measure or measuring tape is a flexible ruler used to measure length or distance. It consists of a ribbon of cloth, plastic, fibre glass, or metal strip with linear measurement markings. It is a common measuring tool. Its design allows for a measure of great length to be easily carried in pocket or toolkit and permits one to measure around curves or corners. Today it is ubiquitous, even appearing in miniature form as a keychain fob, or novelty item. Surveyors use tape measures in lengths of over 100 m. Types There are two basic types of tape measures with cases: spring return pocket tape measures and long tape measures. Spring return pocket tape measures will generally fit in a pocket. They are small; the case is up to about three inches across. The tape is returned to the case by a spring mechanism. Pocket tape measures have a tape in length and across. A second tape measure design is what is called the long tape. These are cased tape measures with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grade (slope)
The grade (also called slope, incline, gradient, mainfall, pitch or rise) of a physical feature, landform or constructed line refers to the tangent of the angle of that surface to the horizontal. It is a special case of the slope, where zero indicates horizontality. A larger number indicates higher or steeper degree of "tilt". Often slope is calculated as a ratio of "rise" to "run", or as a fraction ("rise over run") in which ''run'' is the horizontal distance (not the distance along the slope) and ''rise'' is the vertical distance. Slopes of existing physical features such as canyons and hillsides, stream and river banks and beds are often described as grades, but typically grades are used for human-made surfaces such as roads, landscape grading, roof pitches, railroads, aqueducts, and pedestrian or bicycle routes. The grade may refer to the longitudinal slope or the perpendicular cross slope. Nomenclature There are several ways to express slope: # as an ''angle'' of inc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bematist
Bematists or bematistae (Ancient Greek βηματισταί (''bēmatistaí'', 'step measurer'), from βῆμα (''bema'', 'pace')), were specialists in ancient Greece and ancient Egypt who measured distances by pacing. Measurements of Alexander's bematists Bematists accompanied Alexander the Great on his campaign in Asia. Their measurements of the distances traveled by Alexander's army show a high degree of accuracy to the point that it had been suggested that they must have used an odometer, although there is no direct mentioning of such a device: The table below lists distances of the routes as measured by two of Alexander's bematists, Diognetus and Baeton. They were recorded in Pliny's Naturalis Historia (''NH'' 6.61–62). Another similar set of measurements is given by Strabo (11.8.9) following Eratosthenes. Eratosthenes calculated the circumference of the Earth based on work of Egyptian bematists. Notes: 1) 1 mille passus = 2) 1 Attic stadion = 3) The route ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distance Measurement
Length measurement, distance measurement, or range measurement (ranging) refers to the many ways in which length, distance, or range can be measured. The most commonly used approaches are the rulers, followed by transit-time methods and the interferometer methods based upon the speed of light. For objects such as crystals and diffraction gratings, diffraction is used with X-rays and electron beams. Measurement techniques for three-dimensional structures very small in every dimension use specialized instruments such as ion microscopy coupled with intensive computer modeling. Standard rulers The ruler the simplest kind of length measurement tool: lengths are defined by printed marks or engravings on a stick. The metre was initially defined using a ruler before more accurate methods became available. Gauge blocks are a common method for precise measurement or calibration of measurement tools. For small or microscopic objects, microphotography where the length is calibrated us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pace (unit)
A pace is a units of measurement, unit of units of length, length consisting either of one normal walking step (approximately ), or of a double step, returning to the same foot (approximately ). The normal pace length decreases with age and some health conditions. The word "pace" is also used for units inverse to speed, used mainly for walking and running, commonly ''minutes per kilometer''. The word "pace" is also used to translate similar formal units in other systems of measurement. Pacing (surveying), Pacing is also used as an informal measure in surveying, with the "pace" equal to two of the surveyor's steps reckoned through comparison with a rod (unit), standard rod or chain (unit), chain. Standardized units Like other traditional measurements, the pace started as an informal unit of length, but was later standardized, often with the specific length set according to a typical brisk or military marching stride. In the United States the pace is an uncommon US customary un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pace Count Beads
Pace count beads or ranger beads are a manual counting tool used to keep track of distance traveled through a pace count. It is used in military land navigation or orienteering. A typical example for military use is keeping track of distance traveled during a foot patrol. Description The tool is usually constructed using a set of 13 beads on a length of cord. The beads are divided into two sections, separated by a knot. Nine beads are used in the lower section, and four or more beads are used in the upper section. There is often a loop in the upper end, making it possible to attach the tool to the user's gear with a simple Larks head The cow hitch, also called the lark's head, is a hitch knot used to attach a rope to an object. The cow hitch comprises a pair of half-hitches tied in opposing directions, as compared to the clove hitch in which the half-hitches are tied in th ... hitch. Usage There are two ways to use the beads. One is to represent the paces the user has wal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walking Distance Measure
The walking distance measure denotes the distance that can be travelled by walking in a fixed amount of time. In Japan, the standard measure for walking distance is 80 meters for 1 minute of walking time. It is the standard used in real estate listings. For example, if a building is a 10-minute walk from a particular park or train station, it is 800 meters away. In the last century, throughout most Middle Eastern countries, it was common to give the distances between cities in walking distances. For example, Khaybar is ten days' journey by foot to Jeddah. See also * Pacing (surveying) * Pace (unit) * League (unit) * Parasang * Biblical mile Biblical mile () is a unit of distance on land, or linear measure, principally used by Jews during the Herodian dynasty to ascertain distances between cities and to mark the Sabbath limit, equivalent to about ⅔ of an English statute mile, or wha ... References External links Units of length Length, distance, or range measuring device ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest Modelling
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' (FRA 2020) found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the predominant terrestrial ecosystem of Earth, and are found around the globe. More than half of the world's forests are found in only five countries (Brazil, Canada, China, Russia, and the United States). The largest share of forests (45 percent) are in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
