Dr. Haval A. Sadeq 2019-2020 Photogrammetry Lab Notes Lab ... · Then start to measure points by clicking on button _4 _ During pressing the button, the points will appear in the

Dr. Haval A. Sadeq 2019-2020

Photogrammetry Lab Notes – Lab work 09 DTM collection and Topographic map

University of Salahaddin –College of Engineering –Geomatics (Surveying) Eng. Department (4/10/2016)-8:30-10:30AM

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In this tutorial the student will learn how to:

How collect 3D coordinates from processed aerial images for topographic mapping (Contour +Vector)

The steps are as follow:

1. to start measuring 3D coordinates, the images should be processed (see previous lecture) , this means

that interior and exterior orientation is completed included GCP from the ground and bundle adjustment

succeeded

2. Draw a polygon at the area you want collect points, for drawing follow the following steps,

a. Click on Model

b. Put the 3D mosue on the ground by rotating the wheel till the parallax is zero( the images should

be in stereo)

c. Clcik on the draw polyline click on icon zz or in the Drawing menue selct the icon, a label will

appear at the mid of the vieport , indicates that the command is ready

d. With the 3-D mouse draw the polyline, to specify the poitns use button

e. To draw the polygon points use button”4” and to end the drawing use button “5”

3. clcik on , to open a viewport in order to display the 3D points

4. run the DTM collection from the toolbar or from the Drawing menu select DTM Collection, DTM

collection window will appear,

5. adjust the setting in the window,

a. specify the size

b. click on Model Kappa

6. movement option

a. set as shown in the window




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7. To view the points during the measurements click on point collector window, from the Tools menu

(it is necessary to view this window in order to save the points in a file by clicking on write)

8. Start measure points by clicking on “collect” and then press the button “4” on the 3D mouse.

Note: “collect at” lets you to specify starting point.

Important Note: some times the Z-value will be changed as shown in the below figure and wither it

will be above ground or below, therefore it needs to be adjusted by scrolling the mouse, it says

81.464m,

This should adjusted till the parallax is zero and the mouse in both viewports should be at the same

location




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9. Then start to measure points by clicking on button”4”

During pressing the button, the points will appear in the viewport and the coordinates will be

measured, continue press button”4” till all points are measured.

The final result will be as shown in the below

10. To view the points in color click on icon.

Beyond creating DTM, it is possible to visualize the DTM by right click on the screen and select visualize

It is possible to visualize the view by clicking on the icon , the following window will appear:




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1-to show the contour specify as shown below, and then click on start:

2-To show the DTM with contour specified over the TIN use the following parametrs and then clcik on

start:

To show the tin only specify the following




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To specify the grid and contour use the following options

Note to exit from visualization click on stop.

To control the color and parameters of the contour

and TIN click on style tab, and adjust as required

To load the saved DTM points, which is done by point

collector, click on load points

The points will be displayed in

the Summit evolution program

as shown at the right




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Note: in case if there is outliers (not regular

points) you can select the point and click on

delete.

Crete contour map, To export the created DSM to a CAD or SHAPE

file use the save button that existed in the

Exporting DTM and Contour into CAD and shape file

In this part the student will learn how to export the contours and DTMs into CAD or Esri programs.

1. after collecting the DTM points, and generate the boundary for the area and the buildings in

different layers, Save the points into AutoCAD file using the command in the toolbar (left image), saving all layers:

2. Click on to create contour,

3. Then click on “click to selected” under points tab:

3- specify the location of the file that you saved the CAD file

4-Specify the contour specification, click on contour tab , set CI=1, when finished click on “Generate”

Specify the output format and the location such as DWG (CAD file) or ARGIS shape file the exist in the

Output tab:




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When the contours are generated a report will appears shows he

elapsed time:

Viewer automatically will be displayed showing the result of the DTM

presentation.

In addition to that a CAD,DGN,DXF,or SHP file will be generated as

well, helps to use the result in AutoCAD format (to the right):

Superimpose the contour and vector

1. In the AutoCAD vector file( that you created in the previous lecture) select all objects and then copy to clipboard using( right click→ clipboard→ select copy)as shown below:

2. Return to the AutoCAD file that contains contour lines, and then right click and click on clipboard→ then select “Paste to original Coordinates”: 3. Finally, the final results of the contours and the vector data has been located in one file, which can be used as topographic map.

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Dr. Haval A. Sadeq 2019-2020 Photogrammetry Lab Notes Lab ... · Then start to measure points by clicking on button _4 _ During pressing the button, the points will appear in the