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A subtense bar is a bar of a certain length that has targets located at either end of the bar. In most cases, it is constructed out of a durable material such as invar. It is a method for indirectly measuring distances that is both quick and convenient when it is used in conjunction with a theodolite. The method employing the subtense is comparable to the one that use a tachymeter and graded rod.
Where would you suggest I look for further information on the Subtense bar method?
- Measurement of horizontal distances in almost flat areas.
- a method for determining horizontal distances on terrain with undulations.
- Angles are measured in degrees.
How long is Subtense bar?
As an illustration, the majority of subtense bars were two meters in length, while transits and theodolites typically had angle measurement resolutions ranging from six inches to twenty inches.
What is the fundamental idea behind the stadia method?
The concept of comparable triangles serves as the conceptual underpinning for the stadia method. This indicates that the ratio of the length of the opposing side to the length of the adjacent side, also known as the tangent, remains the same for any triangle with any given angle.
What kind of methodology is utilized in tacheometric surveys?
Tacheometric surveying is a type of angular surveying in which the horizontal distance from the instrument to the staff stations is estimated solely based on the observations made by the instruments themselves. As a result, the chaining processes are no longer necessary.
Method of the Subtense Bar | Tachymetry Ways of Measuring Horizontal Distance | Surveying
39 related questions found
Which method of tacheometry is utilized the vast majority of the time?
Considering the “Stadia Technique” is the procedure that is utilized the most frequently in the industry of tacheometric surveying, we shall explain the thought process that underpins it. The stadia technique is based on the fundamental premise that the ratio of the perpendicular to the base remains the same in all isosceles triangles of the same kind.
What exactly is the fundamental concept of tacheometry?
The tacheometric principle is as follows: The concept of the tacheometer is derived from a feature of isosceles triangles, which states that the proportion between the distance of the base from the apex and the length of the base is always the same.
Which method is used to determine the distance that must be maintained between stadia hair?
12. The distance between the _______ hair and the _______ hair remains the same when using the fixed hair method. The distance between the upper hair and the lower hair, also known as the stadia interval i, on the diaphragm of the lens system is maintained at a constant value in this manner.
The tangential technique refers to what exactly.
Using the Tangential Technique When the staff is too far away to read or when there are no stadia hairs present in the diaphragm of the instrument, the tangential method of tacheometry is utilized. The sighted staff is outfitted with two large targets (or vanes) that are separated by a predetermined amount of vertical distance in this approach.
What are some applications for the Subtense bar?
A subtense bar is a bar of a certain length that has targets located at either end of the bar. In most cases, it is constructed out of a durable material such as invar. It is a method for indirectly measuring distances that is both quick and convenient when it is used in conjunction with a theodolite. The method employing the subtense is comparable to the one that use a tachymeter and graded rod.
What precisely is an EDM survey?
Electronic distance measuring, sometimes known as EDM, is a technique that makes use of electromagnetic waves in order to calculate the distance between two places…. EDM instruments are pieces of surveying equipment that are extremely convenient and dependable, and they have the capacity to measure distances of up to 100 kilometers.
Where does Abney stand in terms of the survey?
A fixed sighting tube, a moving spirit level that is attached to a pointing arm, and a protractor scale make up the components of a surveying equipment known as an Abney level and clinometer…. The user of an Abney level can determine height, volume, and grade by employing trigonometry in the calculation process.
What are some of the applications of tacheometry?
A tachymeter or tacheometer is a form of theodolite that is used for quick measurements and determines, electronically or electro-optically, the distance to target. Tachymeters and tacheometers are also referred to interchangeably.
What does Subtense mean?
: of, relating to, or constituting an object (such as a pole or rod of known length) used to ascertain a distance without actual measurement by observing the subtended angle from a given point subtense method subtense transit.
In tacheometric surveying, what does the subtense approach entail?
Subtense Method This approach is quite similar to the fixed hair method; the only difference is that the stadia interval can be changed. A suitable mechanism is constructed to change the distance between the stadia hair so that they can be positioned against the two targets that are held on the staff at the point that is being observed.
What are the benefits of conducting a survey using tacheometry?
- It is one of the more expedient approaches to land surveying.
- The precision of tacheometric surveying in rough or uneven terrain might be considered to be pretty excellent.
- Does not necessitate the completion of any laborious tasks involving tapes and chains.
- Effective in terms of both money and time investment.
What kind of instrument is utilized to conduct surveys using technometry?
The tacheometer is the instrument that is used for tacheometry. By utilizing it, the horizontal distance may be measured optically or electronically (electro-optically), while the horizontal angle can be computed either numerically or visually.
Tacheometric contouring refers to what exactly?
Tacheometric Method The tacheometric method of indirect contouring involves the putting out of radial lines by making varied angles with respect to a reference line. Tacheometric method of direct contouring After that, the tacheometric readings are taken on the levelling staff that is positioned at a variety of positions along each of the radial lines.
Tacheometric constant refers to what exactly?
Both the stadia interval factor, denoted by the letter K, and the stadia constant, denoted by the letter C, are examples of tacheometric constants. It is required that these constants be determined in advance of any work that requires the use of a tacheometer. Using the approach outlined below, one can derive these from observations made in the field.
What exactly is the tacheometric surveying principle underlying the stadia method?
The stadia technique is predicated on the assumption that the ratio of the perpendicular to the base remains unchanged in isosceles triangles that are comparable to one another. In the figure, let the two rays OA and OB be perpendicular to the central ray OC at the same angle. This constant k is totally dependant on the size of the angle that is being measured. sight or with an angled line of sight.
The meaning of the term “anallatic lens”
Anallactic Lens. Inside the telescope of a tacheometer, there is a specialized convex lens that is positioned in between the object glass and the eyepiece at a predetermined distance from the object glass. The analytic lens’s job is to bring the stadium constant down to zero; that’s its job description.
What is the lowest count that the tachometer will go to?
- theodolite: least count is 20″
- Prismatic compass: least count is 30′
- The leveling staff has a minimum count of 5 millimeters.
- Since the dumpy level is determined by staff reading, the minimum count required is 5mm. This is why the minimum count is 5mm.