Chapter 1 Review Questions

Explain how GIS helps communities plan for the future.

1. Information from the variety of maps and databases can be combined in the GIS and displayed on one map or on a series of them. 2. The GIS lets you combine data to create new information about a place, for example, you can combine digital maps of soils, slopes and land cover to find area suitable for buildings (areas having suitable soils on a gradual slope, not on a wetland.) 3. Since all edits are made on the computer, its easy to map several different scenarios or make changes to the maps. When you are ready you can print many copies of the maps.

Give two disadvantages of using loose-leaf notebooks for recording surveying data.

1. Possible loss of some loose sheets. 2. Having the project data divided between field and office.

What is a plumb line?

A weighted string hund from a fixed point and allowed to become motionless indicated perpendicular to level.

Why is the proper recording of field notes a very important part of surveying practice?

All surveys must be free from mistakes or blunders. A potential source of major mistakes in surveying practice is the careless or improper recording of field notes. The art of eliminating blunders is one of the most important elements in surveying practice. The proper taking of field notes, then it's a very important skill for the surveyor, one that cannot be overemphasized.

What is meant by the term leveling?

An instrument called level which is used to observe the rod a different points, can measure elevation. The relative vertical position of several points separated by long distances can be determined by a continuous series of level rod observations. This procedure is called levelling.

What is the basic advantage of using a data collector or an electronic field book for recording surveying measurements? Will these devices completely replace conventional field books?

Electronic recording devices are used to automatically collect, store and display the date acquired by the electronic surveying instruments to which they are attached. This helps to eliminate possible blunders that may occur when data are manually transcribed into a field book. They serve as a direct link between the electronic total station and the office computer used for data reduction. The reduced or processed data can then be automatically printed and or survey plots or maps can be plotted. Data can be stored directly from appropriate electronic survey instruments, and they can also be entered manually via the keyboard. In addition, descriptive notes or written text can be keyed in by the operator displayed and stored in this electronic device.

How does geodetic surveying differ from plane surveying? Under what circumstances is it necessary to conduct a geodetic survey?

Geodetic survey take the earth's curvature into account. Plane surveying ignores it, and assumes the earth is flat. Geodetic survey is used when there is need to map large areas and to establish large scale networks of points on the earth for horizontal and vertical control.

What surveying instruments are used to measure angles?

Hand level Abney level Dumpy level Automatic level Laser level Transit Theodolite

Explain the difference between a "feature" and an "attribute" in a (M.S. 18-19)

In GIS all objects shown on a map (features) can have information associated with them (attributes). In a municipal taxation map, for example, the individual lots and neighbourhoods are the features. The number of dwellings, type of land use, the taxes paid, and the assessed value are some of the attributes associated with the corresponding features. Each type of feature can be stored and displayed as a layer. Clicking on a particular feature will display its unique attributes.

Is surveying an independent profession? Why?

In recent years surveying has emerged as an independent professional discipline, and the requirements for an appropriate college education in surveying are gradually increasing the U.S.

Is licensure as an LS necessary for all types of surveying work? Explain.

Licensure laws apply only to the practice of land or boundary surveying, and not to construction surveying or any other activity that does not involve the marking or description of property lines.

What is one of the most important rules with regard to survey field notes? Why is it so important? List three other important rules.

One of the most important rules for avoiding costly blunders in surveying work is to be neat, thorough, and accurate in recording the results of field measurements, sketches, and related observations. Also the quality and the appearance of the field notes are a direct reflection of the entire surveying effort.

Give a brief description of the following types of surveys: property survey, topographic survey, construction survey, control survey, forensic survey, and route survey. List six other types of specific surveying applications.

Property Survey- It's performed in order to establish the position of boundary lines and property corners. Its also called land survey, title survey or boundary survey. It's usually performed whenever land ownership is to be transferred or when a large tract of land is to be subdivided into smaller parcels for development. Topographic Survey- It's performed in order to determine the relative positions of existing natural and constructed features on a tract of land. Construction Survey- It's also called layout or location survey and performed in order to mark the positions of new points on the ground. These new points represent the location of building corners, road centerlines and other facilities that are to be built. Control Survey- There are 2 kinds of control surveys Horizontal and Vertical surveys. Horizontal control survey uses temporary/ permanent markers, and places several point in the ground. These points, are called stations. They are arranged throughout the site area under study so it can be easily seen. (More accurate) Vertical control survey is relatively permanent reference points are determined by precise leveling methods. Marked points of known elevation are called elevation benchmarks. The network of stations and benchmarks provide a framework for horizontal and vertical control. (Less accurate) Route Survey- Performed in order to establish horizontal and vertical control to obtain topographic data, and to layout the position of highways, railroads, pipelines, etc. The primary aspect of route surveying is the project area is very narrowing compared with its length, which can extend for many kilometers. 1. Hydrographic Survey 2. Reconnaissance Survey 3. Photogrammetric Survey 4. Cadastral Survey 5. Mine Surveys 6. Bridge Surveys 7. Tunnel Surveys 8. City Surveys

Briefly outline the historical development of surveying.

Surveying dates as far back as 5,000 years ago in ancient Egypt. They used it to accurately layout the great pyramid with respect to the true meridian, and also for the annual floods of the nile river, which obliterated land survey markers used for taxation purposes which were necessary for ancient surveyors to relocate and replace the lost boundaries. The earliest device used to establish a level line was a triangular A-frame with a plumb line and weight suspended from the apex called libella. In 20 b.c another instrument was used by the roman surveyors was called chorobate, a timber beam with a narrow groove on top to hold water as a leveling instrument. The water surface established a level line of sight. The magnetic compass was another surveying instrument it was first used in the 13th century to establish the direction of boundary lines. By the beginning of the 16th century, a sighting device similar to the transit with graduate scales to measure vertical and horizontal angles, was in use. Since the 20th century surveying has emerged as a dynamic and modern technical discipline. Non-military needs for the inventory and management of natural resources, such as surface water and timberlands have also been a catalyst for advancements in surveying, and the increasing use of aerial photography, GNSS, and photogrammetric surveying is attributable to military as well as peacetime needs for large scale and accurate surveys.

Give a brief definition of surveying and describe its two fundamental purposes.

Surveying is a discipline in which all methods of disseminating, processing, and measuring information about the physical earth and our environment. It involves the measurement of distances and angles. The distance may be horizontal or vertical in direction. The 2 fundamental purposes 1. To determine the relative positions of existing points or objects on or near the surface of the earth. 2. To layout or mark the desired position of new points or objects, which are to be places or constructed on or near the surface of the earth.

Why is surveying an important technical discipline?

Surveying is a discipline, which includes all methods for measuring, processing, and spreads information about the physical earth and our environment.

Briefly describe why surveying may be characterized as both an art and a science.

Surveying is an art, because it is dependent up on the skills, judgements and experience of the surveyor. It's also considered and applied science, because field and office procedures rely upon a systematic body of knowledge, related primarily to mathematics and physics.

What is the basic assumption for plane surveying?

Surveying measurements are carried out as if the surface of the earth were perfectly flat. The curvature of the earth is neglected

What general information should a field book contain?

The field book should contain the name, address, and phone number of the owner written on ink on the cover. At least one page at the front of the book is reserved for a table of contents. Pages should be numbered throughout the field book.

Is a horizontal distance a perfectly straight line? Why?

The horizontal direction varies from point to point. It is not a perfect straight line. It's curved like the surface of the earth. A horizontal distance or length is measured along a level surface. At every point along that length. The line is tangent to the level surface is horizontal.

Contact the board of examiners that has jurisdiction over the practice of surveying in your state. Find out what the education and experience requirements are for admission to the LS examination.

The level of education and work experience required to become licensed as an licensed surveyor varies from state to state. It is generally necessary to have several years of experience and an appropriate college degree, but many states allow the applicant to substitute additional years of work experience for the formal education requirements.

What is the basic purpose of statewide professional licensure laws?

To protect the public from possible harm when supposedly "professional" services are offered by unqualified persons, a system of professional licensure laws has been established in each state of the nation.

Define and briefly discuss the terms vertical and horizontal.

Vertical Direction - It is the direction of gravity and is equivalent to a difference in height between two points. Vertical distances are usually measured with wooden or fiberglass rods held vertically and graduated in centimeters or hundredths of a foot. A vertical angle is measure in a plane that is vertical at the points of observation or measurement. Horizontal Direction- The horizontal distance is the direction perpendicular to the vertical direction of gravity. The horizontal distance also varies from point to point. It may be measured by stretching a steel tape between a series of points along a horizontal line, and its measure on a plane that is horizontal on the point of measurement.

What is meant by the term elevation?

When the height is measured between the points with reference to a given level surface, like mean sea level, it is called an elevation.