165 n 166 Answers- English
Traverse:
Traverse is a survey method that measures the directions and
lengths of lines between several points on the ground. Using this, the
coordinates of the points can be calculated. To calculate a traverse, distances
and angles are measured in the field, and then mathematical formulas are used
to calculate the distance and direction between the points using these
measurements. What is a traverse? A survey is made by starting from a point on
the ground and connecting lines to adjacent points in a chain. The directions
and lengths of these lines are measured. The entire survey chain forms a
network. Traverses are classified as "closed" or "open"
traverses. Closed traverse: The survey returns to the starting point and is
closed. Open traverse: The survey ends without returning to the starting point.
How is a traverse calculated? Field measurements: The distances and
directions between successive points are measured using an angle measuring
instrument (such as a theodolite) and a tape or chain. Coordinate
calculation: Using the distances and directions collected from the field,
the coordinates of each point in the land survey are calculated. Error
adjustment: Measurement errors in closed traverses are adjusted.
Errors can be distributed through mathematical methods, using various
adjustment methods such as the "Bowditch" method. Total error
calculation: After the traverse is completed, any difference in returning
to the initial coordinates represents the total error. Some calculation
methods: To calculate coordinates, measured data (angles and distances) from
the field are used. "Chain traverse" is a method that uses only
dimensions. "Axis method" is a method that uses only lengths
rather than angles.
There are two main methods of traverse surveying They are:
1. Closed traverse: It forms a loop-like circuit, where the survey ends back at
the same point where it started. This method is suitable for marking boundaries
and surveying large areas of land (for example, ponds or forests). If any
errors occur in a closed traverse, they can be easily identified and corrected.
2. Open traverse: In this method, the survey starts at one point and ends at
another point. It does not form a closed loop. This method is useful for
surveying long, narrow areas such as roads, railways, canals or coastlines.
Compared to a closed traverse, it is difficult to directly identify errors in
an open traverse. Importance of Traverse Survey Traverse survey is an important
process in the fields of construction and civil engineering. Its importance
lies in the following aspects: Establishment of control networks : In traverse
surveying, a control network is created by setting up survey stations and
measuring their lengths and directions. This network serves as a standard for
future surveys. For long projects: This method is very essential for long and
narrow structures like roads, railways, tunnels and canals. Boundary
identification: The boundaries of properties, lakes and forests can be
accurately identified using closed traverse. Topographic surveys: Traverse
method is used in topographic surveys to collect details like land contours and
elevations. Construction plan: It helps in preparing the layout required for
the construction of infrastructure like bridges and buildings. Possibility of
correction: In case of closed traverse, any errors in the measurements can be
easily identified and corrected. This increases the accuracy of the survey.
Rectangular Coordinates is a mathematical system used to
determine the location of a point . It is also known as the Cartesian
coordinate system. It is named after the French philosopher and mathematician
René Descartes. In this system, the location of a point on a plane is
described in terms of two perpendicular lines (axes). The horizontal line
is called the x-axis. The vertical line is called the y-axis. These two axes
intersect each other perpendicularly (at an angle of 90°). This point of
intersection is called the origin. Its coordinates are (0,0). Parts of
rectangular coordinates: Coordinate Plane: The plane containing the
x-axis and the y-axis. Axes: The x-axis and the y-axis. Coordinates: A pair of
numbers that represent the location of a point. is the distance from the origin
along the x-axis, and is the distance from the y-axis. Quadrants: Two axes
divide the plane of the coordinate system into four parts. These are called
quadrants. They are denoted by the Roman numerals I, II, III, and IV. Uses of
rectangular coordinate systems: In mathematics: Used to plot points in geometry
and to graphically represent equations. In physics: Used to describe the
position and motion of objects. In engineering: Used in construction and
design. In geography: Used to identify locations on maps. In computer science:
It is used to determine the positions of objects in computer graphics and
gaming.
The quadrantal system (also known as quadrantal bearing or
reduced bearing) is a method of measuring directions in surveying. In this
method, the direction is expressed relative to the northern or southern
meridian. The angle is measured from whichever meridian is closest to the
line. Key features: Reference line: The northern or southern meridian is
used as the reference line. Direction: The bearing is always measured east (E)
or west (W) from the nearest northern or southern meridian. Angle range: The angle
value in this measurement is always between 0° and 90°. Notation: The angle is
represented by letters indicating its quadrant. For example, N45°E means an
angle of 45° from north to east in the northeast quadrant. Examples:
Northeast quadrant (NE): If a line is 30° east of north, it is denoted N30°E.
Southeast quadrant (SE): If a line is 30° east of south, it is denoted S30°E.
Southwest quadrant (SW): If a line is 30° west of south, it is denoted S30°W.
Northwest quadrant (NW): If a line is 30° west of north, it is denoted N30°W.
Difference from whole circle bearing: Quadrantal system: Measures angles from
0° to 90° and refers to a quadrant. Whole circle bearing (WCB): Always measures
angles from 0° to 360° clockwise from north.
In surveying, fore bearing and back bearing are angles
measured in opposite directions from each other with respect to the same line .
The difference between these two angles is always if there is no magnetic
attraction at the location where the measurements are made. Fore
Bearing: It is the direction measured from one station (a fixed point) on
a survey route (traverse) to the immediately following station. It is measured
in the direction of survey progress. For example, the bearing measured from
station 'A' to station 'B' is called the fore bearing of the line 'AB'.
Back Bearing: It is the direction measured from one station on a survey
route to the immediately preceding station in the opposite direction. It is
measured against the direction of survey progress. For example, the bearing
measured from station 'B' to station 'A' is called the back bearing of the line
'AB'. Relationship between front bearing and rear bearing: The basic
mathematical relationship between these two is: Rear bearing = front bearing
± The plus (+) sign should be used: when the front bearing is less than . The
minus (-) sign should be used: when the front bearing is greater than .
Example: A line is front bearing 45∘45 raised to the composed with
power 45∘ Then: Rear bearing = 45∘+180∘=225∘45 raised to the composed with
power plus 180 raised to the composed with power equals 225 raised to the
composed with power 45∘+180∘=225∘ . The forward bearing of a line
is 250∘250
raised to the composed with power 250∘ Then: Back bearing = 250∘−180∘=70∘ 250 raised to the composed with
power minus 180 raised to the composed with power equals 70 raised to the
composed with power 250∘−180∘=70∘
. Local Attraction: The effect of
locally located magnetic objects (power lines, iron) causes differences in
compass readings. In these cases, the difference between the forward and
backward bearings may not be exactly . It is essential to measure these two
bearings to detect this and correct errors in the survey.
The magnetic meridian is a vertical plane connecting the
magnetic north and south poles of the Earth, while the magnetic bearing is the
horizontal angle made with the magnetic meridian passing through the endpoints
of a particular line. Simply put, a magnetic meridian is a direction, while a
magnetic bearing is the angle of a line relative to that direction. Magnetic
meridian Definition: A vertical plane connecting the magnetic north and south
poles is called a magnetic meridian. It is the horizontal portion of the
magnetic field lines on the Earth's surface. Use: The magnetic meridian at a
location can be determined using a magnetic compass. Note: The magnetic
meridian is not fixed; it varies slightly over time. Magnetic bearing
Definition: The magnetic bearing of a line is the horizontal angle from one end
of the line to its magnetic meridian. It is the angle made with magnetic north
at a particular time. Measurement: Magnetic bearing is measured using
instruments such as a surveyor's compass. Use: It is useful in navigation and
surveying to determine the direction from one place to another. Key Difference
Meridian: This is a direction (a line). Bearing: This is an angle (referring to
a specific line) relative to that direction.
The answer is given below about establishing and calculating
angles, as well as the correction for convergence. Establishing and calculating
angles Angling refers to the distance between two lines drawn from a given
point. These angles are measured in degrees, radians, or gradians. The
calculation of angles is very important for solving various geometric problems,
in trigonometry, and in engineering applications. Correction for convergence In
surveying and geodesy, a "correction for convergence" is a correction
used to convert the angle at a particular meridian (longitude) to another
meridian. Due to the curvature of the Earth, lines of longitude converge at the
poles. This curvature causes the angle between meridians at two different
points on the Earth to differ. Convergence correction is used to correct this
difference. Using this correction, angles measured at different locations can
be converted to a single standard longitude, thereby obtaining accurate
measurements. Answer: The establishment and calculation of angles are key
concepts in geometry and trigonometry. Convergence correction is a method
used in surveying to correct for the difference in angles caused by the
curvature of the Earth.
Here is a step-by-step guide to setting up a station with an
ETS machine and backsighting using coordinates Station Setup with an ETS
Machine 1. Setting Up the Tripod Select a Location: Select a location where the
tripod can be securely positioned over the survey point. Centering: Center the
tripod exactly over the survey point. Use the optical plummet (a small
telescope used for centering) or laser pointer located under the machine to
align it exactly over the survey point. Stabilizing: Firmly press the tripod
legs into the ground and ensure that it does not move. 2. Setting Up the ETS
Machine Mounting on the Tripod: Place the ETS machine on the tripod head.
Tighten the screw firmly, but do not overtighten. Leveling: Using the leveling
screws on the ETS machine, keep the machine perfectly horizontal (level). This
can be easily done with the help of the electronic bubble on the machine. 3.
Entering information into the machine Power on: Turn on the machine. Creating a
project: Create a new project for the survey or select an existing project. Job
selection: Select a job and enter data collection mode. 4. Backsighting using
station coordinates Method description: Backsighting using station coordinates
and backsight coordinates is a method used to orient the machine based on two
known points. This allows all angular values of the machine to be linked to a
real-world coordinate system. Steps: Enter Station Coordinates: Select the
"Occ. Orientation" or "Station Setup" option on the machine.
Station Coordinates (Occupied Point): Enter the Northing, Easting, and
Elevation coordinates of the point where you set up the machine. Instrument
Height: Measure the height of the machine (from the ground to the center of the
telescope) and enter that value. Enter Backsight Details: Select the
"Backsight Coordinate (NEZ)" option. Backsight Coordinates: Enter the
Northing, Easting, and Elevation coordinates of the point where you want to
backsight. Prism Height: Measure and enter the prism height above the backsight
point. The backsight height is not required for the measurement, but is useful
for later measurements. Backsighting: Prism Aiming: Point the telescope at the
prism on the backsight point. Alignment: Adjust the machine so that the
crosshair is centered on the prism. Measure: Press the "Measure"
button on the machine. The machine will automatically measure the backsight
point coordinates. Orienting: The machine will now automatically correct its
direction using your backsight point and station coordinates. After this process,
the machine is ready to measure all points in the project. With this method,
the machine is oriented in the correct direction and all measurements are
recorded in the correct coordinate system.
Creating a new job (task) and calculating area (area
calculation) is an important process on an Electronic Total Station (ETS)
machine. The process may vary slightly between different brands and models, but
the general procedure is as follows: Creating a job on an ETS machine Creating
a new job means creating a new file to survey, in which all the data you have
collected will be stored. Turn on the machine: Turn it on by pressing the
machine's power button. Go to the main menu: Once the machine starts, you will
see the main menu screen. Select the data menu: From the main menu, select the
'DATA' or 'FILE' option. Select a job: Press F3 or the corresponding button to
select the 'JOB' option. Create a new job: Select the 'NEW JOB' option. On some
machines, you can select an empty job and rename it. Name the job: Asks you to
name the new job. Use the keypad to enter the project name, date, or any
recognizable name (for example, TS1). Confirm selection: Confirm the job
creation by pressing the Enter or OK button. Now, you can record your survey
data in this new job. Area Calculation After creating a new job, you need to
set up the machine and start the survey. Area calculation is done as follows:
Measure points: Measure all vertices that lie within the boundaries of the area
you want to measure. Set up the total station at a stable location and aim at
the survey points (with the help of a prism). After measuring each point,
record its data (coordinates) in your job. Go to the area calculation menu:
After you have recorded all the boundary points, press the 'MENU' button. Go to
the 'CALCULATIONS' or 'COGO' (Coordinate Geometry) menu from the available
options. Select area calculation: Select the option 'AREA' or 'AREA
CALCULATION'. Select points: The machine will now ask you to select the points
for which you want to calculate the area. Select all the boundary points
sequentially from the list of points you have previously measured and stored.
This will create a closed structure. View the result: After selecting all the
points, press the 'CALCULATE' or 'OK' button. The machine will calculate the
area and display it on the screen. The area will be displayed in hectares,
square meters, or other units. If necessary, you can change the units. With
these steps, you can easily create a new job on the ETS machine and calculate
the area accurately.
DGPS stands for Differential Global Positioning System . It
improves on the standard Global Positioning System (GPS). It determines
location more accurately by correcting for errors in standard GPS. While
standard GPS provides an accuracy of up to 15 meters, DGPS increases this to 1
to 3 centimeters. How DGPS Works The DGPS system works based on two main
components: Reference station (base station): This is a GPS receiver
installed at a fixed, precise location on the ground. It receives signals from
satellites and calculates the difference between its actual location and the
location shown by the satellite. Rover receiver (mobile station): This is
another GPS receiver located at the user's disposal. It receives signals from
satellites, and at the same time receives correction information sent by radio
signals from the reference station. Using this correction information, the
rover calculates its position with great precision. Use of DGPS in the
fields In the agricultural sector, accurate location determination is of utmost
importance. DGPS helps farmers a lot in achieving this accuracy.
Precision Agriculture Field Mapping: It is used to create detailed field
maps that show variations in soil type, moisture levels and crop health. Based
on this, farmers can make right decisions about sowing, irrigation and
pesticide application. Automated Steering Systems: By using DGPS-based
automated steering systems in tractors and other machinery, they move along
pre-set paths with utmost precision. This reduces the need to plough or spray
the same place multiple times, saving time, fuel and labour. Variable Rate
Application: Using DGPS, different amounts of fertiliser, seeds or pesticides
can be applied to different areas of the field. This approach increases crop
yields and reduces wastage. Land Surveying and Boundary Determination
Land Boundaries: DGPS is very useful for determining the exact boundaries of
land. This helps in avoiding boundary disputes. Land Measurements: DGPS surveys
are useful for accurately measuring the area and shape of large fields.
Irrigation Management Efficient Irrigation: It helps in identifying the
undulations in the field and managing the irrigation systems effectively. For
example, DGPS is useful in leveling the fields to distribute water evenly. DGPS
technology is increasing the accuracy in agriculture, paving the way for
farmers to achieve higher yields with less resources.
Reconstructing a traverse using an ETS (Electronic Total
Station) machine typically requires surveying techniques, data processing, and
electronic total station expertise. You can use this approach to reestablish
lost or destroyed survey points or to check existing points. Here is a general
way to reconstruct a traverse: 1. Planning and Preparation Collect Old Data:
Collect all available data related to the old traverse, including coordinates,
distances, angles, and sketches. This information is needed to determine the
locations of the lost points. Inspect the field: Examine the traverse route,
its old points, and the surrounding area. Look for any physical evidence (for
example, rocks, wooden sticks, or other markings) that may help identify the
lost points. Establish Control Points: Select at least two safe and stable
points that can be used for reconstruction. These should usually be old, known
coordinate points (benchmarks) near the traverse to be restored or points
outside the traverse. 2. Data collection using the ETS Set up the machine:
First, set up the ETS on an available control point. Center and level the
tripod stand and ETS properly. Take a backsight: Take a backsight on the second
point of your control points. This will provide the orientation for the ETS.
Measure new points: Use the Traverse/Transfer Station program on your ETS
machine. After the backsight is complete, move along the traverse path,
measuring the positions of the lost points. At each new station, move your ETS
to that location and take a backsight again on the old point. Locate old
points: Use your ETS to locate lost traverse points. Enter the old coordinates
in the ETS and move in the direction indicated by the machine to find the
point. 3. Data processing and adjustment Download field data: After you have
collected the data, transfer the data from the ETS to a computer. Make
adjustments: Use the software to correct any discrepancies between the old
traverse data and the newly collected data. This usually involves methods such as
the "transit rule" or "compass rule". Check: Check the sums
of the interior angles. In a closed traverse, the sum of the interior angles
should be equal to (N-2) * 180 degrees, where N is the number of sides in the
traverse. 4. Reestablishing points Mark new points: Enter the adjusted
coordinates into the ETS and use the machine to establish new points (for
example, iron rods or cement markings) at the correct location. Verify: Recheck
the positions of the points in the final step to ensure that the traverse has
been successfully restored.
There are some important rules for setting up a survey
field. Generally, these rules are based on accuracy, clarity and the purpose of
the survey. Rules to be followed while setting up a survey field: Going from
whole to part: According to this principle, the entire area should be surveyed
first and then divided into small parts. By doing this, any errors will be
contained in a small part and will not affect the entire survey. Measuring from
two reference points: When identifying survey points, measurements should be
taken from at least two fixed and clear reference points. By doing this, the
exact location of the point can be confirmed. Clear purpose: The purpose of the
survey should be clearly defined in advance. For example, it should be clear
whether it is to mark land boundaries, lay out a layout for a building or for
road construction. Choosing a method: The right survey method should be chosen
based on the purpose and area of the survey. Depending on the types of
survey, methods such as chain survey, compass survey, plane table survey can be
chosen. Accuracy: Accuracy is very important in surveying. The level of
accuracy required should be determined by the project requirements.
Measurements should always be checked to minimize errors. Documentation: All
survey activities, measurements, and observations should be recorded
accurately. This should include field notes, diagrams, and careful recording of
details such as date and time. Official Permissions: In some cases, especially
in the case of land surveys, official permissions such as owner permission or
court order may be required. Checking Equipment: Before starting the survey,
ensure that all equipment to be used is in good condition. Damaged or faulty
equipment can affect the results of the survey. Marking Boundaries: When
marking land boundaries, if there is any confusion, the boundaries should be
clearly marked. Inspecting the Area: Before conducting the survey, note any
obstacles in the area. If necessary, remove them to facilitate the survey. Marking
Points: Survey points should be marked in a visible and stable manner. By
following these rules, the survey field can be set up accurately and
efficiently.
Field Measurement Book (FMB) is a crucial document that
records the exact measurements and boundaries of land, maintained by the
government in the Village Administrative Office (VAO) or Revenue
Department. Surveyors record land measurements in sketches, which are
used to verify land parcels, resolve disputes and assess land before
purchase. Key purposes of Field Measurement Book (FMB): Accurate
Measurements: Records the exact measurements and boundaries of land
parcels. Land Verification: Helps to verify the exact location,
area and measurements of a land parcel. Dispute Resolution:
Identifies survey numbers and provides a basis for resolving land
disputes. Land Purchase: It is an important document for buyers to
assess land properly before purchasing it. How to get FMB sketch: You can
apply for a copy of the FMB for your land on portals such as the National
Government Services Portal.
A village map is an official map showing the survey numbers
of all the lands, roads, tanks, government places and other important
geographical details of a village. These maps are maintained by the land
records departments of the state governments. How to get a village map online
Different states have set up portals to view their land records online.
Depending on your area, you can use the following methods: Andhra Pradesh
Meebhoomi Portal: The Andhra Pradesh government maintains a website called
Meebhoomi (meebhoomi.ap.gov.in).
You can view or download the map (FMB/LP) of your village on this portal.
Meeseva Portal: You can also get a copy of the village map through the state
government's Meeseva portal. Required details: To get the map, you need to
enter your district, mandal, village and survey number.
"A Register" refers to the process of formally
recording information, which can be used in a variety of contexts, such as
computer hardware (CPU register), legal documents (land registration), or
employment details. It means to maintain or record a record. Computer
terminology: A small, very fast memory area in a central processing unit (CPU).
It is used to store and process data. Registration process: Signing up or
registering for something. For example, registering to vote or enrolling for a
class at a college. Legal/Government documents: Recording details about
something, such as land or property. For example, a land registration contains
geographic information about land. Employment registration: A document used by
employers to maintain details about their employees (e.g., Form B). Language:
This refers to the different ways in which people use language depending on the
situation in which they speak. For example, formal or informal conversations.
The Great Trigonometrical Survey Station can be translated
as 'Great Trigonometrical Survey Station' in Telugu. It is part of the 'Great
Trigonometrical Survey' launched in India in 1802 by the British East India
Company. This project was intended to measure and map the entire Indian
subcontinent with precision. Important facts: Start of the project: The project
was started in 1802 by British officer William Lambton. Purpose: The main
purpose of this survey was to scientifically survey the territory of India and
to accurately determine its heights and longitudes. Method: The land was
measured using the method of trigonometry in this survey. For this purpose,
similar stations were established in various parts of the country. Surveyor
General: The important officer in this project was Sir George Everest, after
whom Mount Everest was named. Current Status: Some of the benchmark stations
set up as part of this survey are still in place in various parts of the
country. These stand as a testament to India's survey history.
Comments
Post a Comment