Lab 4B Line Map Compilation, Orthorectification and Digital Elevation Model (DEM) - Advanced Photogrammetry (GLS 615)

The aim of this lab is to produce a Orthophoto Images and a Line Map by using a DEM concept. Orthophotographs are photographic images constructed from vertical or near-vertical aerial photographs, such that the effects of central perspective, relief displacement, and tilt are (practically) removed. Orthophoto can be obtained by resampling aerial image with fiducial marks. It can be used as base map because it has all the original features in the image. Plus, orthophoto also can be used to measure true distance of features within the image. Orthophoto in digital can be generates using images from aerial and space borne sensors. Orthophoto is used for it increased availability of digital data, easier acquisition of input data, powerful computers that can store data and increased of demand of up to date maps.


Software used:

PHOTOMOD 5.0 Lite

My report and procedure:

1. Lab 4b Line Map Compilation, Orthorectification and DEM
2. Line Map
3. Digital Elevation Model

Lab 4a Aerial Triangulation - Advanced Photogrammetry (GLS 615)

  Aerial triangulation is a mathematical process of establishing precise and accurate relationships between the images coordinate system and defined datum and projection on the ground. The main objective of aerial triangulation is to produce from ground control point and any other sufficient points in the photogrammetric model to make sure for each model can be oriented accurately as required for stereopair compilation in either orthophoto or line mapping. The process uses all possible overlaps image with a few number of reference points. There are mainly three stages of aerial triangulation, one of them is preparation by making point identification of ground control point, numbering of points, images and strips, and the flight details such as photo coordinate, camera calibration and scanned or digital images. Second, Interior orientation is important to relate aerial image to the object on the ground which used to determine the fiducial marks measurement for cameras. Then, relative orientation is made followed by block adjustment where it includes algorithm for determination of blunders and error propagation.

Software used:

PHOTOMOD 5.0 Lite

My report and procedure:

Lab 4a Aerial Triangulation

Tutorial Exercise - Advanced Photogrammetry (GLS 615)

    This tutorial exercises are associated with the Advanced Photogrammetry syllabus. This tutorial exercises will give more understanding on how photogrammetric surveying works. Additionally, it covers all the concept of photogrammetric fundamentals, including the calculation related to the land surveying for example land area calculation, elevation differences above datum, and Geography coordinate system.

Tutorial :

1. Tutorial 1
2. Tutorial 1B
3. Tutorial 2A
4. Tutorial 2B
5. Tutorial 2C
6. Tutorial 2D
7. Tutorial 2E
8. Tutorial 3A and 3B
9. Tutorial 4
10. Tutorial 5
11. Tutorial 5B
12. Tutorial 6
13. Tutorial 7

Notes and References :

Advance Photogrammetry Syllabus Notes


Answers :

All Tutorial Answers

Lab 5 Close Range Photogrammetry - Advanced Photogrammetry (GLS 615)

  Close-range photogrammetry is another type of photogrammetric data collection and processing where the subject is less than 300 meter. Collection method can be both ground or aerial-based and the final output can be performed either two or three dimensionally. The close-range photogrammetry relies on the reconstruction of the object simultaneously from several images from different and possible perspective to ensure a suitable geometry of intersecting rays. Photogrammetric would be useful if the object to be measured is inaccessible or difficult of access. Second, the object is very small. Third, when it is not certain at the time of measurement and what measures are required. There are many types of application used in close-range photogrammetry, one of them is to preserve cultural heritage.

Software Used :

PHOTOMOD 5 Lite

My Report and Procedure of Close-Range Photogrammetry lab :

Lab 5 Close-Range Photogrammetry - GLS 615

Advanced Photogrammetry (GLS615) Syllabus Notes

This subject deals with digital photogrammetry, photogrammetric orientations, automatic point measurement, photogrammetric triangulation, generation of Digital Terrain Model (DTM) and orthoimages, photogrammetric project planning, and close range photogrammetry. At the end of the course, students should be able to: Manage the hardware and software operations in the digital photogrammetric workflow, analyze numerical and graphical data in a photogrammetric process and combine operations in photogrammetry to produce photogrammetric outputs.

Advanced Photogrammetry (GLS615) Notes :

1. GLS615 Syllabus Content
2. A Review of Photogrammetric Principles
3. Digital Photogrammetry
4. Generation of Digital Photogrammetric Images
5. Photogrammetric Orientations
6. Digital Image Matching
7. Photogrammetric Triangulation
8. Block Adjustments and Automatic Aerial Triangulation (AAT)
9. Generation of Digital Terrain Models
10. Generation of Digital Ortho-images
11. Photogrammetric Project Planning
12. Principle of Close Range Photogrammetry

Lab 3 Ground Control Point - Advanced Photogrammetry (GLS615)

Ground control points are used in conjunction with GPS data collected during the flight to increase the accuracy of the area being surveyed. By creating visible attributes within the area being flown and knowing an accurate GPS coordinate on these attributes, aerial photography is able to take this information and create a survey grade map. A great example of how much time and money can be saved by using photogrammetry and GCP’s as a replacement for standard surveying techniques. GCP's are a great way to increase the accuracy of any map that uses aerial captured images.

Post-marked control uses points of natural detail or physical markings on the image emulsion (Aerotriangulation). Such points are visible on the photograph and can be uniquely and unambiguously defined. The point selection is made on the basis of the type of point, that is 3D, horizontal or height.

My Report and Ground Control Point selection :

Lab 3 Ground Control Point (GLS615)

Assignment 2 Close Range Photogrammetry Application - Advanced Photogrammetry (GLS 615)

Close-range photogrammetry is meant to be when the distance from the camera to the object of interest can be from 1 to 300 meter. The close-range photogrammetry relies on the reconstruction of the object simultaneously from several images from different and possible perspective to ensure a suitable geometry of intersecting rays. Photogrammetric would be useful if the object to be measured is inaccessible or difficult of access. Second, the object is very small. Third, when it is not certain at the time of measurement and what measures are required. They are many types of application that are among the most important in close range Photogrammetry.

Download Link :

My Assignment 2 

Assignment 2 - Close Range Photogrammetry Application (GLS615)

Assignment 1 Camera Calibration - Advanced Photogrammetry (GLS 615)

Camera calibration is very important before start a photogrammetry works, one of the importance is to determine its precise and accurate values for a number of constant. Therefore, accurate spatial information can be determined from photographs. There are 3 types of technique of camera calibration in photogrammetry and several type of output parameter after the camera has been calibrated.

Technique of Camera Calibration :-

1. Laboratory Method
2. Stellar Calibration Method
3. Field Calibration Method

Output Parameter :-

1. Tangential lens distortion
2. Calibrated Focal Length
3. Radial Lens Distortion
4. Principal point
5. Affinity

My Assignment and Report :

Assignment 1 - Camera Calibration (GLS 615)

Lab 2 Flight Planning - Advanced Photogrammetry (GLS 615)

Good result of photogrammetric project depends on acquisition of good quality pictures. Due to weather and ground conditions, time frame for photography is limited. Because the redo of this type of survey surely expensive and causes long delays on project. This task must be carefully planned and executed according to flight plan. Consists of flight map and specifications. The design of aerial photography flight in order to obtain desired photos at a certain scale. Flight crew should be able to interpret weather conditions and make sound decisions on whether to fly or not.

Software Used : 

AutoCAD 2007

My Report and calculation :

Lab 2 Flight Planning (GLS615)

Lab 1 Scanning - Advanced Photogrammetry (GLS 615)

     

 The first step before processing the aerial photograph is we need to convert this aerial photo in to digital format by scan it. Since there are new and advanced technologies are existed we are no longer using stereoplotter to process the aerial photo. In digital format, the aerial photo can be safe stored and it also can prevent it from damage thus maintain the image clarity. Other than that, digital format of aerial photo can make image processing lot easier compared to stereoplotter by using a Photomod software which is mainly used to process the data obtain from the aerial photo. To scan there are variety of picture format, as for the task we were recommended to scan into Tiff format. As for the picture resolution, we set to 600 Dpi (Dot per Inch) which is suitable for the image be process in that software and the computer on the lab satisfied with it system requirement that allow the processing smoother and faster.

My Report and Procedure :

Lab 1 Scanning (GLS615)