Islamic University of Gaza Civil Engineering Department ...
Islamic University of Gaza Civil Engineering Department Surveying II ECIV 2332 By Belal Almassri Chapter 7 Coordinate geometry and traverse surveying Part 2 Resection
Traverse Surveying Definitions Types, Utilizations and advantages Computations and correction errors Examples 6. Resection As in the following figure, the horizontal position of a new point like P can be Determined
by measuring the horizontal angles to three points of known coordinates like: A & B & C A c B b R
M N P C
Procedure: Let J = + then J = 360 ( M+ N+ R ) AB AC compute & & b & c & R from AB A,ACB ,C . the known coordinates of points: (R= ) 2- compute J = 360 ( M+ N+ R ) 3- compute H = b sin M / c sin N
4- compute ( tan = sin J / (H + cos J )) 5- compute 180 - N AP =AC 6- compute = + 7- compute AP = b sin / sin N 8- compute Xp AP& Yp Xp = XA + AP sin AP Yp = YA + AP cos
1- Example 7.6: Traverse Surveying Definitions: Traverse is one of the most commonly used methods for determining the relative positions of a number of survey points. Traverse is a method in the field of surveying to establish control networks. It
is also used in geodetic work. Traverse networks involved placing the survey stations along a line or path of travel, and then using the previously surveyed points as a base for observing the next point. Utilizations: property survey to establish boundaries. Location and construction layout surveys for highways, railways and other works. Helps the surveys for
photogrammetric mapping. Types of Traverse: a- Closed Traverse Traverse b- Open Advantages: Less organization needed. Few observations needed. More accurate than other methods. Suits different types of utilizations Open Vs Closed:
Closed traverse is useful in marking the boundaries of wood or lakes . Open traverse is utilised in plotting a strip of land which can then be used to plan a route in road construction. Choice 1. 2. 3. 4.
of traverse stations: As close as possible to the survey details. Traverse shortest line should be greater than 1/3 of the longest line (preferred to be equal). Traverse stations should be selected in firm ground. From one station we can see the back sight and the foresight. Underground . . . .
Computations and correction of errors A- Determine the Azimuth of each line: 1- When ( 1 + ) > 180 2 = - ( 180 1) = + 1 - 180 2- When ( 1 + ) < 180 2 = + 180 + 1 = + 1 + 180 B- Checks and correction of errors : X last point X first point = X all lines Y last point Y first point = y all lines In order to meet the previous two conditions,
the following corrections are performed: 1- Angle correction: a- Closed loop traverse: For a closed traverse of n sides, - sum of true internal angles = (n 2 ) 180 - error = sum of measured angles ((n 2 ) 180 ) - correction per angle = - error / no of internal b- connecting traverse: If the azimuth of the last line in the traverse is known, then the error
- = c (calculated azimuth) - n (known azimuth) - correction / angle = - / n the corrected azimuth - i = i ( initially computed azimuth) i ( / n)i ( initially computed azimuth) i ( / n) 2- Position correction: IF the calculated and known coordinates of last point are: ( X c , Y c ) & ( X n , Y n )respectively, then : - Closure error in x-direction( x ) = X c X n - Closure error in y-direction( y ) = Y c Y n - Closure error in the position of the last points = x + y
Compass ( Bowditch ) Rule : used for position correction as follow: Correction to departure of side ij( x) = -(length of side ij / total length of traverse)( x ) Correction to departure of side ij( y) = -(length of side ij / total length of traverse)( y ) Correction can be done directly to coordinates: Cxi = - (Li / D) ( x ) & Cyi = - (Li / D) ( y ) Where: Li=the cumulative traverse distance up to station i &D=total length of the traverse
The corrected coordinates of station i ( x'i , y'i ) are: X'i = Xi + Cxi & Y'i = Yi + Cyi Allowable error in Traverse surveying Azimuth and bearing North to east or west / South to east or west
The Water Cycle. Water Cycle. The continuous movement of water between Earth's surface and its atmosphere. Water changes from one form to another. The sun is the source of energy for this process. Evaporation. Process where liquid changes to gas....
Geographer: Abdel Omran (not important) Main Ideas: There is a pattern of the causes of death as your move through the DTM. Visual: Real Life Example: Cholera is a big killer is stage 2. World Systems Theory. Geographer: Immanuel Wallerstein.
The compressed air powered FN 303 launcher is designed to fire less lethal projectiles exclusively, with an effective range of 50 meters at a point specific target for law enforcement and a maximum range of 100 meters for military applications....
In The Kite Runner, Khaled Hosseini uses the literary device of foil to help enhance the major motifs - of loyalty, devotion, and love - in the novel. The only way to fully understand the foil and its purpose is...
Forecast BIAS . is described as a tendency to either . over-forecast (meaning, more often than not, the forecast is more than the actual), or. under-forecast (meaning, more often than not, the forecast is less than the actual).
Poor Richard's Almanac Almanac: an annual publication containing information, observations, and advice What was in an Almanac? Practical information about the calendar Sun and moon phases Weather (from the previous year) Agricultural advice Aphorisms & proverbs What's an Almanac?
Intro to a FORTINET webinar: "I am certain you are fully aware how digital transformation is a business enabler, but it has also created an unending digital attack surface, on top of existing challenges like unprecedented complexity companioned with point...
Latent content is the unconscious wish represented by the dream imagery. Freudian Dream Symbols Symbols in the unconscious come from repressed desires. Long, pointed, or otherwise elongated images are phallic and refer to the male aspect (power, aggression/assertiveness, procreation) associated...
Download Presentation
Ready to download the document? Go ahead and hit continue!