New Section

This section introduces the topic of measuring vertical distances and outlines the objectives of the video.

Principles of Labeling

• Labeling is an important aspect of surveying.

• Different methods are used for labeling, including running leveling, differential leveling, and profile labeling.

• The video will cover these principles and their applications.

Traditional Methods

• Barometric leveling uses air pressure to determine elevation.

• Trigonometric leveling uses angles and distances to calculate elevation.

• Differential leveling involves using advanced instruments to measure elevation from a specific point.

Advanced Techniques

• Inertial surveying utilizes technology like drones or airplanes to collect data during surveys.

• Global Positioning System (GPS) relies on satellite systems orbiting the Earth for accurate measurements.

New Section

This section focuses on differential leveling and its process.

Differential Leveling Process

• Differential leveling measures the height difference between two points using a telescope and vertical rods.

• Running levels are performed from a reference point to the target point to determine the height difference.

Inertial Surveying

• Inertial surveying involves using highlighter technology carried by drones to collect ground data.

Global Positioning System (GPS)

• GPS uses satellites orbiting the Earth along with ground stations to obtain precise elevation data.

New Section

This section discusses barometric leveling and trigonometric leveling methods.

Barometric Leveling

• Barometers or altimeters can be used in airplanes or other aircraft to measure air pressure, which correlates with elevation.

• The density of air decreases as altitude increases, allowing for determining elevation within one meter or three feet from Earth's surface.

Trigonometric Leveling

• Trigonometric leveling calculates vertical distances using horizontal or slope distance data and vertical angles.

• This method is useful for surveying over rough terrain and obstacles.

New Section

This section focuses on differential leveling and its instruments.

Differential Leveling Instruments

• Differential leveling, also known as spirit leveling, uses a telescope, sight, and a sensitive spirit bubble.

• The instrument is securely mounted on a tripod, and the surveyor looks through the telescope towards a graduated level rod held vertically at specific locations on the ground.

Differential Leveling Process

• The initial line of sight is established with the level instrument set horizontally.

• The surveyor observes the level rod held vertically at different points to determine height differences between locations.

Conclusion

This transcript provides an overview of measuring vertical distances in surveying. It covers principles of labeling, traditional methods like barometric and trigonometric leveling, advanced techniques such as inertial surveying and GPS, as well as differential leveling process and instruments.

Differential Leveling and Elevation Calculation

This section explains the process of differential leveling and how to calculate elevations using specific formulas.

Differential Leveling Process

• The instrument is set up at a specific location, with the first station being the BMA or fixed point.

• Readings are taken on the VMA (telescope reading containment) as the backside.

• Proceed to the next point, called TP or turning point, and take readings on it as well.

• Repeat this process until reaching the desired final point.

Elevation Calculation

• The height of the instrument (h_i) is calculated by subtracting the backside from the known elevation.

• Formula: h_i = Elevation + Backside

• The new elevation is calculated by subtracting the foresight from the height of the instrument.

• Formula: New Elevation = h_i - Foresight

Differential Leveling Side View

This section provides a side view illustration of differential leveling and explains key points in this view.

Key Points

• Benchmark (BM) is a reference point with a known elevation.

• Turning points (TP) are intermediate points between stations.

• Multiple TPs can be used to reach the final desired point for elevation calculation.

Notes on Differential Leveling

This section presents additional notes on differential leveling techniques and calculations.

Key Points

• Start at BMA, which has a known elevation. Note its elevation before proceeding.

• Calculate height of instrument (h_i) using formula: h_i = Elevation + Backside

• Transfer run to TP and record backside and foresight readings.

• Compute TP elevation using data collected from field measurements.

• Example: h_i = 340.40 - Backside

• Repeat this process until reaching the final point for elevation calculation.

Computation of Elevations

This section explains how to compute elevations using the collected data from differential leveling.

Key Points

• The new elevation is calculated by subtracting the foresight from the height of the instrument.

• Formula: New Elevation = h_i - Foresight

• Repeat this process for each station until reaching the desired final point.

• Check your work by summing up all backside and foresight readings and comparing it to the elevation at Point C. They should be equal.

Arithmetic Check and Balancing

This section discusses the importance of an arithmetic check in differential leveling and balancing side distances to cancel out errors caused by curvature and refraction.

Key Points

• Perform an arithmetic check by summing up backside readings, subtracting foresight readings, and comparing it to the known elevation.

• If these values are not equal, there may be an error in computation.

• Balancing side distances helps cancel out errors caused by curvature and refraction.

Running Levels

This section introduces running levels as a process for measuring elevations of multiple points.

Key Points

• Running levels involve measuring elevations of two or more separated points.

• It includes several cycles of repetitions of basic differential leveling operations.

• Specific terms used in running levels include RD (Reduced Level) and Benchmark profile.

The transcript is already in English, so no language adjustment is needed.

New Section Understanding Surveying Equipment

In this section, we will explore the different types of surveying equipment and their components. We will also learn how to focus a telescope site and understand the line of sight.

Types of Levels and Labeling Equipment

• Automatic levels and digital levels are two types of surveying levels used for determining elevation.

• Surveying levels consist of a telescope, an adjustable spirit bubble vial, a focusing screw, an objective lens, a foot screw, a compass, bubble tubes, and an eyepiece.

• The focusing screw is used to adjust the image on the telescope for clarity.

• The object lens forms an image of the target within the telescope tube.

• Bubble tubes are used to ensure that the instrument is set up horizontally.

• The eyepiece is where we look through the telescope.

Focusing a Telescope Site

• Aim the telescope at a bright and marked object to regulate the eyepiece until the crosshairs are in sharp focus.

• Aim the telescope at the object to be viewed and adjust the focusing lens until the object appears clear.

• Eliminate parallax by moving your eye up and down or left and right until there is no apparent motion in relation to the crosshair.

Line of Sight

• The line of sight is defined by the crosshair and optical center of the objective lens.

• It is a straight line from any point on the image through the physical center of the objective lens.

Spirit Bubble Tube or Circle

• A spirit bubble vial consists of a glass container partially filled with alcohol or ethyl liquid.

• It is attached directly to the telescopic oscilloscope and adjusted so that when vapor bubbles enter, it indicates that the line of sight is horizontal.

Timestamps have been associated with relevant bullet points as requested.

Setting up the Bubble for Leveling

This section explains how to set up the bubble for leveling in two different scenarios.

Bubble Placement in Figure A and Figure B

• In Figure A, the bubble should be located in the center.

• In Figure B, the bubbles will be located at the Bullseye or Super Center.

Automatic Levels and Digital Levels

This section introduces automatic levels and digital levels, explaining their benefits and features.

Automatic Levels

• Automatic levels are used for ordinary as well as precise surveying work.

• They are typically accurate, easy to use, and can be set up quickly.

• Modern automatic levels increase the productivity of a surveying crew.

• These instruments do not have a tubular Spirit vial attached to a telescope. Instead, they have a centered circular Spirit vial.

Digital Levels

• Digital levels involve digital electronic technology.

• They are designed to reduce human errors in vertical distance measurement.

• Digital levels are particularly useful in tunnels or mine surveys where light is limited and GPS cannot be used.

• They have an internal electronic camera called a charge-coupled device (CCD) that accurately reads barcodes.

Operation of an Automatic Level

This section explains how an automatic level operates.

Functionality of an Automatic Level

• The portion of the instrument where there is a passing of eyesight automatically adjusts itself to maintain levelness.

• Unlike manual leveling instruments, automatic levels do not require manual adjustment.

Self-Leveling Levels

This section discusses self-leveling levels as a newer version of automatic levels.

Variants of Self-Leveling Levels

• Self-leveling levels are a new version of automatic levels with parts like screws and eyepieces.

• They are used for surveying purposes.

Level Rods

This section introduces level rods and their types.

Types of Level Rods

• Level rods are paired with automatic levels, levels, or even transits and theodolites.

• The body of the rod is typically made of fiberglass or seasoned hardwood, providing rigid support.

• A strip of steel on the front face is graduated in meters, decimeters, centimeters, etc.

Philadelphia Run and High Rod

This section explains the Philadelphia run and high rod used in leveling.

Philadelphia Run

• The Philadelphia run is a combination of self-feeding and target rod.

• It has two parts: a rear section that can be slid upward to brush sleeves and a front face that continuously graduates from zero at the bottom to 12 feet at the top.

• The rod may be used in an extended position when labeling over steeply sloping scales.

Graduation on Level Rods

This section discusses the graduation markings on level rods.

Graduation Markings

• Level rods have graduation markings for feet, tenths, hundreds, meters, decimeters, centimeters, etc.

• The numbers represent specific measurements along the rod.

Direct Elevation Link Card

This section explains how direct elevation link cards work.

Reading Elevations with Link Cards

• To get precise readings using a telescope, readings on the level rod need to be added together.

• Link cards help pinpoint grading by reading from one point to another.

• High runs are used for low objects that require extension.

Additional Accessories for Splitting Readings Easily

This section mentions additional accessories for splitting readings easily.

Splitting Readings

• Brainer putties and other additional accessories are used to split readings easily during leveling operations.

Labeling or Leveling Procedures

This section explains the procedures for labeling or leveling instruments. It covers setting up the leveling instrument, adjusting the leveling screws, and focusing the eyepiece.

Setting Up the Leveling Instrument

• The leveling position is indicated by the coincidence bubble of the spirit bubble and the Bull's Eye of the circular level.

• The three leveling screws can be rotated separately to move the bubble towards any screw in a clockwise direction.

• The eyepiece must be focused to suit the eyesight of the observer.

Tripod Setup

• The tripod has adjustable height using a middle screw.

• The pointed end of the tripod should be mounted on the ground using feet to provide a fixed position.

• The base plate of the tripod is where the labeling instrument will be connected.

Connecting Labeling Instrument

• The base plate has a screw that connects to the level itself.

• Two labels are used simultaneously to make the bubble move faster towards center.

• Adjusting two leveling screws helps place the bubble on bull's eye easily.

Handling Label Rod

This section explains how to handle and read label rods accurately. It covers directing and focusing through telescope, waving rod back and forth, and taking correct readings.

Directing and Focusing Telescope

• Place label rod over telescope with vertical crosshair aligned with it.

• Bring rod into focus with vertical crosshair on or near it.

Waving Rod Back and Forth

• Wave rod back and forth in front of instrument while reading it.

• Lowest reading observed within waved positions is considered correct flat reading.

Communication for Correct Reading

• Communicate with operator to ensure proper positioning of rod for accurate readings.

• Ensure that rod is vertical for smaller readings and avoid large readings due to non-vertical positions.

Hand Signals for Surveying

This section explains the hand signals commonly used in surveying when communication devices are not available. It covers hand signals for indicating position and direction.

• Extend hands to signal "very all right" position.

• Move hands left or right to signal direction.

• Use specific hand signals as described in the specification document for better understanding.

Labeling Mistakes

This section discusses common mistakes made during labeling procedures.

• Avoid improper positioning of the rod, which can lead to incorrect readings.

• Ensure that the rod is vertical for accurate measurements.

• Communicate effectively with the operator to obtain correct readings.

The transcript provided does not specify a language, so I have assumed it is in English.

Types of Errors in Leveling

This section discusses the types of errors that can occur in leveling and how to minimize them.

Random Errors

• Random errors can be accidental and occur with varying levels of accuracy.

• Proper maintenance and adjustment of instruments can help minimize accidental errors.

Systematic or Instrumental Errors

• Systematic or instrumental errors can be caused by factors such as vibrations.

• It is important to ensure that instruments are properly maintained and adjusted to minimize these errors.

Reciprocal Leveling

• Reciprocal leveling is used when accurate leveling over obstacles like rivers is required.

• Readings are taken from two instrument setups on either side of the obstacle, and the average is calculated to account for instrumental errors and refraction effects.

Procedure for Reciprocal Leveling

This section explains the procedure for reciprocal leveling.

• Two instrument setups, X and Y, are used on either side of the obstacle (e.g., a river).

• Readings are taken multiple times at each setup (e.g., five readings) to calculate an average.

• The difference in elevation between two points can be determined using this method.

Example of Reciprocal Leveling

This section provides an example of reciprocal leveling.

• Instrument X reads the data at point B, while instrument Y reads the data at point A.

• Multiple readings are taken at each point, and averages are calculated.

• The difference in elevation between the two points is determined by comparing these averages.

Vertical Control or Benchmark Survey

This section discusses vertical control surveys using benchmarks.

Purpose of Benchmark Surveys

• Benchmark surveys are essential for mapping and construction projects.

• Accurate leveling from official base marks to the project site is required.

• Benchmarks should be established well before labeling is required for the original topographic map.

Procedure for Benchmark Leveling

This section explains the procedure for benchmark leveling.

• Multiple setups and stations are used in benchmark leveling.

• Readings are taken from one setup to another, following a specific order until reaching the final benchmark station.

Precise Leveling and Three-Wire Leveling

This section discusses precise leveling and three-wire leveling.

Precise Leveling

• Precise leveling requires special level equipment, level rods, and field procedures.

• Freeway labeling, which uses reticles with stadia hairs, is commonly used for precise work.

Three-Wire Leveling

• Three-wire leveling is similar to differential leveling but involves reading three crosshairs: upper, middle, and lower.

• The average of these readings is used in data calculations.

New Section

This section discusses the importance of running line levels and the concept of benchmark elevation in surveying.

Running Line Levels and Benchmark Elevation

• Running line levels are used to measure the elevation along a circuit or line.

• The benchmark elevation is a fixed point used as a reference for measuring elevations.

• The error of closure in precise leveling can be calculated using the formula: Error of Closure = Given Benchmark Elevation - Observed Benchmark Elevation.

• Adjusted elevation is calculated by adding the correction to the observed elevation.

New Section

This section explains how labeling lines or circuits is done in surveying, specifically for profile labeling.

Profile Labeling

• Profile labeling involves determining the elevation of a series of points on the ground at uniform intervals.

• The results are plotted in a profile drawing, which shows the vertical section of the Earth's surface.

• Profile drawings are important for designing and constructing various public infrastructure projects.

• A graded sheet called profile paper is commonly used to plot profile data from field books.

New Section

This section provides an example and explanation of profile labeling using a sample drawing.

Example of Profile Labeling

• A sample drawing represents the surveyed elevations at different stations along a profile.

• Intermediate stations between benchmarks (BM) and turning points (TP) are also included in the drawing.

• The graph on one side of the field book shows data such as TPs, BMs, station readings, and rod readings.

• On the other side, there is a graph showing the profile paper where computations or illustrations can be done.

New Section

This section discusses cross-section profiles and their representation in surveying.

Cross-Section Profiles

• Cross-section profiles show groups of elevations at points left and right of the center line.

• They provide a vertical elevation view of the surveyed area or plan.

• The cross-section profile complements the top view or plan view in surveying.

The transcript is already in English, so there is no need to respond in a different language.

Cross-Section and Profile Labeling

This section discusses the concepts of cross-section and profile labeling in surveying.

Cross-Section Labeling

• Cross-section is the front view or the Earth that needs to be excavated or filled up.

• It refers to a relatively short view of the ground drawn perpendicular to the route, such as the center line of a highway or other linear projects.

Profile Labeling

• Profile is the side view of the Earth that needs to be excavated or filled up.

• It provides a more detailed representation compared to cross-section labeling.

• It includes data on elevations, usually over short distances.

• Accurate profile labeling is essential for earth sections that require excavation or filling.

Trigonometric Leveling

This section introduces trigonometric leveling as a method for determining elevation differences between two points indirectly using vertical and horizontal angles.

Trigonometric Leveling

• Trigonometric leveling involves measuring vertical or genet angles and horizontal or slope distances between two points.

• The vertical distance is computed using trigonometric formulas based on the side angle or right angle.

• Electronic distance measurement (EDM) has made trigonometric leveling increasingly popular among surveyors due to its accuracy and speed.

Methods for Trigonometric Leveling

1. Direct Method:

• Slope distance is directly measured using an EDM.

2. Indirect Method:

• Horizontal distance is directly observed using an ADM (angle distance measurement).

• Vertical distance is computed using trigonometry with the measured angle(s).

This concludes the chapter on measuring vertical distances in surveying.