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STUDY ON THE HEIGHT MEASUREMENT OF CULTURAL FEATURE
BASED ON THE SINGLE AERIAL PHOTO
Li Ersen * , Zhang Baoming, Guo Haitao, LuJun, Zhao Yong, Chen Ke
Zhengzhou Institute of Surveying and Mapping,-Henan, 450052
lixiaosen01784@sohu.com
Commission IV, WG IV/1
KEYWORDS: Photogrammetry, Projection Error, Radicalization Distance, Monoposition
ABSTRACT:
As an important property information, the height information of buildings possesses quite high utilizing value in the civil fields. The
traditional method to get the heights of artificial buildings is to carry on the measurement on stereopairs, This method acquires work
departments to have stereometers and professional workers, further more, it calls for advanced software and hardware, so it disagreed
with those non-professional surveying and mapping departments. This paper studied how to ensure the height information of
buildings by the projection error on single aerial cartographic photography. The technology could not need costly software and
hardware to measure on stereopairs, depressed the speciality ability of workers, and make the technology approach to obtain the
height information of buildings more broadly. Further more, the projection error on images is corresponding to the vertical edge of
culture features which passes photo nadir points, it’s easy to carry on automatic extraction to the vertical edge, so this method owns
very large potential to the direction of robotization. This paper has implemented experiments and precision analysis to the method
and proved that its feasibility and high precision.
1. INTRODUCTION
Along with the continuous development of the city construction,
the amount of the high buildings and large mansions grows day
by day, so the high buildings’ height information becomes to be
an necessary parameter in the activity of city planning,
economic decision-making. The traditional method to get the
heights of artificial buildings is to carry on the measurement on
stereopairs. This method acquires work departments to have
stereometers and professional workers, further more, it calls for
advanced software and hardware, so it disagreed with those
non-professional surveying and mapping departments. This
paper studied how to ensure the height information of buildings
by the projection error on single aerial cartographic photography.
The technology could not need costly software and hardware to
measure on stereopairs, depressed the speciality ability of
workers, and make the technology approach to obtain the height
information of buildings more broadly.
2. THE BASIC PRINCIPLE OF THE HEIGHT
INFORMATION EXTRACTION METHOD BASED ON
THE SINGLE AERIAL PHOTO
In photogrammetry, the projection error is an important
conception. It is caused by the terrain relief and is on the radial
line. Based on the traditional photogrammetric theory, the
rigorous formula of the projection error is:
r
1 — sin® sin 2a
y~ (1)
Ah .
1 r sin (o sm la
2 Hf "
Based on the above formula, we can get the formula to compute
the height information as follows:
In Photogrammetry, there are three main methods to get the
height information of the buildings: the height information
extraction based on the single aerial photo, the height
information extraction based on the stereopairs and the height
information extraction based on the multi-source data. In our
country the researchers have made great study on the method
based on the stereopairs, these years, people begin to study the
height extraction method based on the laser radar data, there is
little study on the height information extraction based on the
projection error, besides, there is great potential to extract the
height information automatically(On the aerial photos, the
projection error of an image point corresponds with the vertical
line of the building, the photo nadir point is on the vertical line,
so it is relatively easy to extract the vertical line). So, study on
the method of height information extraction based on the single
aerial photo has great significance.
Ah = ■
2JH
(2)
r n (If - r n sin (p sin 2o)/5h a + r n sin (psin 2a
For tilt imagery, approximate altitude difference formula:
Sh„
Ah =
H
(3)
r n ( 1—— sin (p sin 2a)
For plane imagery, altitude difference formula:
a 7 Sh
Ah = —H
r
(4)
In the above formulas V n , §h a ,H, Ah , f, a , (p separately
represents radicalization distance of photo nadir point ,