AN APPLICATION OF ATTITUDE AND TERRESTRIAL DATA 
TO GEOMETRIC CORRECTION OF AERIAL SCANNER IMAGERY 
Dr.Krystian Pyka 
Prof.Dr. Zbigniew Sitek 
Photogrammetric Section 
University of Mining and Metallurgy 
Kraków, Poland 
Commission I W.G.1 
1. Introduction 
Aerial scanner images in terms of geometry, resolution, and 
fidelity depart radically from their photographic 
counterparts. Geometric distortions of the scanner images are 
caused mainly by combination of the dynamic image generation 
with the variation of the exterior sensor orientation during 
the flight time. They are rather complicated because the 
dynamic distortions superimpose to the deformations introduced 
by the errors of interior orientation elements of the sensor. 
The correction of these image deformations requires either 
representation of data orientation parameters or a dense set of 
ground control points. However, the time dependent orientation 
data measured by aircraft instruments are till now directly 
known with adequate accuracy. From the other hand, the 
identification of a large number of ground control points 
appears a time-consuming procedure.Since 1970's various methods 
of scanner image correction have been developed [Konecny 1971, 
1972, 1975, 19761, [Baker et.al.1975], [Ebner 1978], [Kraus 
19761, [Gopfert 19811], [Weisel 1981) and [Schur 1983]. The 
method presented in the paper uses both attitude data 
Cparameters measured during the flight) and terrestrial data 
Cground control points), and can be applied to correction of 
single scanner images taken from an aircraft. Digital terrain 
model CDIMO is necessary when relief of the terrain 
contributes to radial distortion higher than à pixel size. 
&. The method of correction 
The input data are scanner digital data stored on CCT 
Cwhich contain also video data and flight parameters) and 
coordinates of ground control points as well as DTM terrain 
information, which can be gathered from large scale maps. 
The exterior orientation data are denoted as: 
5 8 {x ot” Your "ov "0 0 UN } 
where: i = - number of pixel line 
X + t : T , = ground coordinates of instantaneous 
où ot" où 
projection centre for pixel line i Cat the beginnig 
known only in flight local coordinate system and 
therefore, later transformation to ground coordinate 
system is required), 
o.» $9. x, angles of instantaneous scanner orientation 
for pixel line t. 
The coordinates of ground control points X » Y ., Zz, and image 
n 
coordinates AL Jn are expressod as: 
120