Photogrammetry is the method of obtaining the information regarding the physical objects through process of creating, measuring and interpreting the photographs of that particular object.
There are two major parts of Photogrammetry-
(1). Aerial Photogrammetry and (2).Terrestrial Photogrammetry.
In first one, the photographs of the area is taken by camera mounted on airplane. In later, the photograph is taken by camera mounted on or near ground level. Terrestrial (Ground) Photography has limited use in plotting special feature of any hill or cliff feature whereas Aerial Photography has wider application in topographic survey, preliminary route survey of any highway, railway or pipeline.
In these blog, We are going to discuss about Aerial Photogrammetry:
Aerial Photogrammetry is broadly classified into two categories:
There are two major parts of Photogrammetry-
(1). Aerial Photogrammetry and (2).Terrestrial Photogrammetry.
In first one, the photographs of the area is taken by camera mounted on airplane. In later, the photograph is taken by camera mounted on or near ground level. Terrestrial (Ground) Photography has limited use in plotting special feature of any hill or cliff feature whereas Aerial Photography has wider application in topographic survey, preliminary route survey of any highway, railway or pipeline.
In these blog, We are going to discuss about Aerial Photogrammetry:
Aerial Photogrammetry is broadly classified into two categories:
- Vertical Photographs
- Oblique Photographs
In vertical photographs, the axis of camera is vertical i.e. it coincides with axis line of gravity of camera. When the axis of camera is coincide with datum line, the photograph is truly vertical. But when axis of camera is titled slightly, it is called Titled photograph. The tilt is generally less than 1 degree but rarely exceeds 3 degree.
When the axis of Camera is largely inclined to vertical, then it is called Oblique photograph. The axis of camera is intentionally kept inclined.
When the axis of Camera is largely inclined to vertical, then it is called Oblique photograph. The axis of camera is intentionally kept inclined.
Vertical Photograph
Vertical Photograph is already define in above paragraph.
Scale of Vertical Photograph
Scale= Map distance/Ground distance
---eq. no.1
where f = focal length of lens of camera
H= height of camera from MSL
h = height of ground from MSL
You can easily solve the numerical problems by using above equation.
Horizontal distance between two points on ground
By using scale relation (eq.no.1), We can calculate the ground co ordinates of any object and thus distance between two objects on ground.
From Point A
From Point B
And the distance AB is given by
Relief Distance in a Vertical Photograph
Relief distance is defined as lateral displacement or shift in photographic position of object due to its relief ( means elevation of object above/ below the datum line.)
If object is above datum line, then relief is outward but if object is below datum line, relief is inward.
If the object is at MSL, then Relief distance will be given by
If the object is above MSL, then Relief distance will be
where
= Distance between base of tower and MSL.
IF YOU WANT TO GET "HAND WRITTEN NOTES AND IES MASTER BOOKS FOR GATE AND IES" PLEASE CLICK ON LINK AND SUBMIT FORM TO GET LINK.
---eq. no.1
where f = focal length of lens of camera
H= height of camera from MSL
h = height of ground from MSL
You can easily solve the numerical problems by using above equation.
Horizontal distance between two points on ground
By using scale relation (eq.no.1), We can calculate the ground co ordinates of any object and thus distance between two objects on ground.
From Point A
From Point B
And the distance AB is given by
Relief Distance in a Vertical Photograph
Relief distance is defined as lateral displacement or shift in photographic position of object due to its relief ( means elevation of object above/ below the datum line.)
If object is above datum line, then relief is outward but if object is below datum line, relief is inward.
If the object is at MSL, then Relief distance will be given by
If the object is above MSL, then Relief distance will be
where
= Distance between base of tower and MSL.
IF YOU WANT TO GET "HAND WRITTEN NOTES AND IES MASTER BOOKS FOR GATE AND IES" PLEASE CLICK ON LINK AND SUBMIT FORM TO GET LINK.
= Distance between base of tower and MSL.
IF YOU WANT TO GET "HAND WRITTEN NOTES AND IES MASTER BOOKS FOR GATE AND IES" PLEASE CLICK ON LINK AND SUBMIT FORM TO GET LINK.
0 Comments