CT MIB o» ate 7 EEE
A SIMULATION STUDY ON THE IMPROVEMENT OF AERIAL
TRIANGULATION BY NAVIGATION DATA
Peter Friess
Stuttgart University
Stuttgart, Federal Republic of Germany
Abstract
Directly observed camera orientation data are highly
effective, if processed together with photogrammetric
measurements by joint block adjustment. Extensive simul-
ations have been performed for different accuracy levels
of the navigation data and for different ground control
assumptions. The design and the most interesting results
of the simulations are presented and the far reaching
conclusions are briefly discussed.
1. Introduction
In the last few years new high precision navigation
techniques have been coming up fast. The utilization of
navigation data for aerial triangulation will soon be
possible. The high effectivity of directly measured
camera orientation data as "auxiliary" data in aerial
triangulation is well known. The improvement of the
accuracy of photogrammetric blocks is considerable, if
photogramemtric and additional data are processed
together by joint block adjustment, as earlier studies
/1/2/ with statoscope and APR-data have shown.
With the Global Positioning System (GPS), an inertial
navigation system or an integrated navigation system,
which consists of an inertial navigation unit and a GPS
satellite receiver, one will have the possibility to
record the exterior orientation elements continuously
during the photo flight mission. A simulation study /3/
has shown that aircraft positioning with GPS alone
provides a real time accuracy in the coordinates of 5 -
12 m and with an integrated navigation system position
accuracy of 0,5 m could be attainable.
This paper presents extensive simulations which have
been carried out in order to get a general survey of
attainable accuracies in aerial triangulation, if
navigation data could be used as additional data in the
joint block adjustment. It is assumed that camera
orientation elements are derived more or less directly
from navigation systems. The data are treated as obser-
vations (for exterior orientation (OEO) and are
introduced in the bundle block adjustment via additional
observation equations. The bundle program PAT-B was
extended accordingly and has been used. . for all
computations.
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