Part 4: Conclusion

Your conclusion should include the following at a minimum:

A discussion on your analysis on how well your traverse met the project

requirements. Also, comment on the level of agreement between your computed

traverse station coordinates and those obtained using GNSS.

A discussion of any large differences and/or other issues encountered and

recommendations for addressing them (e.g., more data, different field procedures,

updated equipment calibration, different processing procedures, etc.). If no large

differences or other issues were encountered, you may still wish to provide

recommendations for further improving the accuracy of your final station

coordinates (e.g., differential leveling between stations to improve vertical

accuracy).

●/n INTRODUCTION..

METHODOLOGY..

New Parking Lot Expansion Project

CE 361

Submitted by:

Andreson, Alenezi

December 4, 2022

TABLE OF CONTENTS

Table of Stations and Ground Distances..

Change in Elevations...

GNSS Coordinates…..

Found azimuth using coordinates...

Trav 2.2 Compass rule adjustment coordinates..

.3

.4-7

.4

5

5

.6

.6 Orthometric heights of stations...

Final Table of values...

ANALYSIS..

Comparisons of GNSS and Transverse Coordinates..

Introduction:

7

7

.8

.8

Our company has completed a traverse around the North Mcnary field to set up construction

control stations for the new parking lot expansion project. To complete this project we used a

Leica total station, serial number (insert it) and a leica 360 degree prism. For this project we kept

the rod height constant at 5 ft tall and used a bipod to keep the rod steady when possible.

The first step in this whole project was setting up our station markers out in the field. When we

did this we marked station ties to be able to find the stations at the time of the traverse. On the

day of the traverse we got to the field with our total station, rod, prism, tape measurer and

psychrometer. The first thing we did when we got out to the field was set up our prism and rod on a station. We

decided to go counter clockwise when we did our traverse so we set our rod and prism on the

station to the left of our total station. Then we set up our total station and set all of the settings

we needed. A total station uses the pressure, humidity and temperature to account for the errors

due to the air. So we used the psychrometer to get these values for each reading with the total

station. Once we get the total station set up we can start taking measurements.

The first part of taking the measurements in aiming the total station at the backsight. Once we do

this we set that to be our zero point that has no angle to it. Then we plung the scope which means

we turn it 180 degrees and reshoot the measurement. After we do that we unplung the total

station and move the prism to the station to the right. We then turn the total station to the

foresight (the prism in front of the total station) but we have to make sure it is the angle to the

right as that is how we get our interior angle. Then we just repeat this until we get around the

whole traverse.

On the first run of our traverse we did not get under 55 seconds of angular misclosure so we had

to go out into the field again and redo parts of the traverse. The second time around we met all

the requirements. Then on a later date we went out and got real time and static GNSS data to ge

coordinates

For the traverse we needed to get under an angular misclosure of 55 seconds, under a 1 part in

5000 relative error of closure and and an elevation error of less than 0.2 feet. All of these being

plus or minus the value. For the angular misclosure we are looking to see if our angels we find

are equal to 720 (sum of interior angles for a 6 sided shape). The relative error of closure is how

far off of the original station you are based on your angles and lengths. The one part in 5000

means every 5000 ft we go we will have an error of 1 ft from the original point. Then the

elevation misclosure is just the change in elevation from the point you started on.

Methods:

The first thing we did was take our interior angles at each station and reduced it by finding the

mean of the angles and adjusting ours accordingly. We do this to account for discrepancies in the

instrument. Then for our average horizontal ground distance we took the mean of the four

different shots. The reason we have four different readings is because we have the direct and

reverse as well as the foresight and backsight. Then for the grid distance we multiplied our

answers by our combined scale factor for the north field.

STA

Table of Stations and Ground Distances

Interior Angle Ground Distance (ft)

Average Ground Distance (ft) 13

14

15

16

17

18

198°04'23"

63°13'18"

107°15'57"

153°27'58"

158°23'30"

39°34'47"

231.28

163.34

260.33

175.7

116.62

319.26

Side of Traverse

13-14

14→15

15-16

16-17

17-18

18-13

The change in elevations were found using the total station during our traverse, So we had four

readings for each elevation change(direct,reverse,foresight,backsight). When we calculated our

sum of the elevations we found that we only had an error of -0.01 ft. For adjusting the elevation

we decided to deal with it by adding 0.01 ft to the biggest difference in readings we had. This was

the elevation change from 15 to 16, after applying these corrections it brought us to a zero

elevation change.

Change in Elevations

231.267

163.331

260.315

175.69

116.613

319.241

Avg. ▲ Elev. (ft)

2.63

0.53

-3.4

-0.76

0.24

0.75

Σ of ▲ Elev.

Adjusted Elev. (ft)

2.63

0.53

-3.39

-0.76

0.24

0.75

Σ of ▲ Elev. STA

13

After we calculated all of our traverse computations, we took real time and static GNSS data to

get coordinates for our points. During this process we used a LEIGS14 antenna at 2.000 meter

rod height. For the real time data we set up above each station for about 30 seconds and collected

the data. We repeated this for all of the stations. For the static data collection we set up above

station 15 for 20 minutes. Using these coordinates we can find a grid azimuth for one of our

points. We needed to choose a point that we wanted to find the coordinates for as well as the

azimuth to input into Trav 2.2, we chose station 13. So we found our azimuth from 13 to 14.

Then we took the coordinates for 13 and 14 and found the departure and latitude. From there we

went and found our starting azimuth.

14

15

16

17

18

-0.01 ft

Side of Traverse

13-14

GNSS Coordinates

Northing [ift]

340323.55

340333.88

340476.27

340421.86

340312.29

340211.07

Found azimuth using coordinates

0.00 ft

Easting [ift]

7479907.97

7479676.95

7479756.89

7480011.46

7480148.84

7480206.73

Azimuth

272°33'44"