MODULE 1 Flashcards
What is the other term for surveying?
geomatics
It is the science, art, and technology of determining the relative positions of points above, on, or beneath the Earth’s surface, or of establishing such points.
Surveying
It is the discipline that encompasses all methods for measuring and collecting information about the physical earth and our environment, processing that information, and disseminating a variety of resulting products to a wide range of clients.
Surveying
What were the earliest applications of surveying?
measuring and marking boundaries of property ownership
The results of today’s surveys are used to:
- map the Earth above and below sea level
- prepare navigational charts fro use in the air, on land, and at sea
- establish property boundaries of private and public lands
- develop data banks of land-use and natural resource information that aid in managing our environment
- determine facts on the size, shape, gravity, and magnetic fields of the earth
- prepare charts of our moon and planets
What are the two general classifications of surveys?
- geodetic
- plane
These are surveys that cover a small part of the earth’s surface, its curvature need not be taken into account.
Plane Surveys
These are surveys in which the earth’s curvature must be considered.
Geodetic Surveys
These are surveys that are made of setting land boundaries on the ground and determining areas of land parcels.
Cadastral Surveys or Land Survey
These are surveys that are made for discovering the shape of the ground and plotting it on a map along with natural and artificial features.
Topographic Surveys
These are surveys of the sites where the construction of an engineering nature is to be undertaken.
Engineering or Construction Surveys
These may also be classed under engineering surveys. They comprise surveys of linear constructions such as railroads, highways, canals, and transmission lines and include the layout of lines and grades for these projects.
Route Surveys
These consist of surveys for locating the working below the earth’s surface as in mines, tunnels, and aqueducts.
Underground Surveys
These are surveys that utilize photographs taken from an airplane.
Aerial Surveys
What do you call the field that deals with the measurements of aerial surveys?
Photogrammetry
These are surveys which are made for determining the shape of the bottom of lakes, rivers, harbors, and oceans.
Hydrographic Surveys
They are tasked with the precise identification of established land and its corners.
Relocation Survey
They are the ones that put mojon/mohons on the lands they are surveying.
Relocation Survey
They are more focused on subdivision platting.
Subdivision Survey (PSD)
They are tasked with the monumentation and survey data on a map in conformance with the local subdivision ordinance and the Subdivision Map Act
Subdivision Survey (PSD)
They split a tract of land into smaller parcels.
Subdivision Survey (PSD)
They split two or more tracts of land into smaller parcels.
Consolidation-Subdivision Survey (CSD)
They survey lands with no title, no number, or lands that are completely basal.
Original Survey (OS)
They verify the measure of untitled lands.
Verification Survey (VS)
They are tasked with giving titles or surveying land that an individual occupies.
Segregation Survey (SGS)
It is a document evidencing ownership of the land granted or awarded to the beneficiary by the Department of Agrarian Reform (DAR).
Certificate of Land Ownership Award (CLOA)
What is the mohon mark for a private surveyor?
P.S.
What is the mojon mark for the surveyor of the Bureau of Lands?
B.L.
What is the mojon mark for the surveyor of the Agrarian Reform?
A.R.
It is the cylindrical concrete used for marking boundaries of lands.
Monson/Mohon
It requires a combination of human skill and mechanical equipment with utmost judgment.
Good observation
Observations may be made ______ or ________.
- directly
- indirectly
Examples of this are applying tape to a line, fitting a protractor to an angle, or turning an angle with a total station instrument.
Direct observations
A/an ________ is secured when it is not possible to apply a measuring instrument directly to the quantity to be observed.
Indirect observations
It is defined as the difference between the true value and the measured value of a quantity.
error
It is a deviation of an observation or a calculation from the true value and is often beyond the control of the one performing the operation.
error
Give seven examples of errors.
- Tape not standard length
- Imperfect alignment of tape
- Tape not horizontal
- Tape not stretch straight
- Imperfection of observation
- Variations in temperature
- Variations in tension
These are also known as biases.
Systematic Errors
These results from factors that comprise the “measuring system” and include the environment, instrument, and observer.
Systematic errors
As system conditions remain constant, the systematic errors will remain ________.
constant
If conditions change, the magnitudes of systematic errors ___________.
also change
Because systematic errors tend to accumulate, they are sometimes called ___________.
cumulative errors
These are those that remain in measured values after mistakes and systematic errors have been eliminated.
Random errors
They are caused by factors beyond the control of the observer and obey the laws of probability.
Random errors
Another term for random errors
Accidental errors
They are present in all surveying observations.
Random errors
The sources of errors in surveying measurement are classified under three groups:
- instrumental errors
- natural errors
- personal errors
These are errors due to imperfections in the instrument used, either faults in their construction or from improper adjustments between the different parts prior to their use.
Instrumental errors
These are caused by variations in the phenomena of nature such as changes in magnetic declination, temperature, humidity, wind, refraction, gravity, and curvature of the earth.
Natural errors
These errors are principally from limitations of the senses of sight, touch, and hearing of the human observer which are likely to be erroneous or inaccurate.
Personal errors
These are inaccuracies in measurement that occur because of some aspects of a surveying operation that is performed by the surveyor with carelessness, inattention, poor judgment, and improper execution.
Mistakes
These are caused by a misunderstanding of the problem, inexperience, or indifference of the surveyor.
Mistakes
Give four common mistakes in surveying:
- Adding or dropping a full tape length
- Reading an angle counterclockwise, but indicating it as a clockwise angle in the field notes
- Transposition of numbers
- Reading wrong meter mark
It is the difference between two observed values of the same quantity.
Discrepancy
It indicated there probably no mistakes and random errors are small.
Small discrepancy
True or False. Small discrepancies preclude the presence of systematic errors.
False - they do not
It refers to the degree between observed values of the same quantity and is evaluated on the basis of discrepancy size.
Precision
If multiple observations are made of the same quantity and small discrepancies result, this indicates __________.
high precision
The ___________ attainable is dependent on equipment sensitivity and observer skills.
degree of precision
It denotes the absolute nearness of observed quantities to their true values
Accuracy
It is defined as the number of times something will probably occur over the range of possible occurrences.
Probability
Adjustments of Weighted Observations:
- The weights are inversely proportional to the square of the corresponding probable errors.
- The weights are also proportional to the number of observations.
- Errors are directly proportional to the square roots of distances.
