EVALUATION OF DIGITAL CAMERAS FOR PHOTOGRAMMETRIC MAPPING 
Qassim A. Abdullah, Ph.D. 
Director of Research and Technical Development 
Photo Science, Inc. 
45 W. Watkins Mill Rd. 
Gaithersburg, MD 20878 
U.S.A. 
Commission I, Working Group 1/3 
KEY WORDS: Digital CCD Camera, Softcopy, Autocorrelation, Airborne Sensor 
ABSTRACT 
A CCD digital camera with 2044x2022 pixels array was tested as an airborne imaging system for the purpose of metric mapping. 
The KODAK Mega Plus was flown at 6500 ft over an area in Desloge, Missouri. The digital data was then transferred to a 
softcopy photogrammetric station where digital aerial triangulation was performed. A digital elevation model was obtained from 
auto-correlation on some of the frames of the block and two-foot contours were generated and compared to the existing set of 
contours generated by conventional photogrammetry. Although the shapes of the contours generated by both methods seem to 
agree in shape and behavior, the results revealed a bias in the DEM obtained from the softcopy approach. The results strongly 
suggest the digital frame camera coupled with softcopy techniques are ready for photogrammetric mapping after an accurate 
calibration of the camera interior parameters. 
1. INTRODUCTION 
This decade witnesses the maturity of the digital frame camera 
(DFC) for commercial, industrial, and scientific photography. 
When we talk about DFC we specifically mean those cameras 
which carry the same configuration and concepts of the 
conventional film camera except in having a set of light sensitive 
devices or sensors called a charge-coupled device (CCD) 
arranged in a square or rectangular block called an “array”, 
instead of the conventional film as a recording media. The 
advantage of adopting the geometry and the mathematical models 
of the current film for future cameras such as DFC is very 
appealing for the photogrammetric community as it translates into 
a shorter learning curve as the same concept of flight planning 
and execution will be employed with almost no change. This will 
multiply the return of our recent investment in softcopy systems, 
as the DFC will be adoptable by the recent soft copy system 
without any modifications or new mathematical modeling. 
The DFC in general has some advantages over the current film 
camera as it has better geometric stability when you consider the 
deformation in the film of the film camera, better radiometric 
image quality and dynamic range, and capability for real time in- 
flight viewing (King, et al.. 1994). Only in the last few years 
have we witnessed the development of the DFC for productive 
system in remote sensing for qualitative measurements of natural 
resources. Very few of these systems exist in the commercial 
market today and among them is the system developed by 
Positive System and the USDA Forest Service (T. Bobbe, et al. 
1994). When it comes to the use of such systems for 
photogrammetric mapping, only a few attempts have been made 
to question the capability of such cameras for photogrammetric 
mapping. King and his colleagues did the most in this field 
(King, et al. 1994, 1993, 1992). 
i 
King's research showed satisfactory results although the 
investigation was performed on one single model and did not take 
into consideration the stability of a traditional block 
photographed by the DFC. The paper presents the methodology 
and the results of a complete photogrammetric project from start 
to finish using soft copy techniques, i.e., DFC and softcopy data 
collection and processing in order to evaluate the feasibility of 
using DFC for aerial mapping. 
2. METHODOLOGY 
2.1 Digital Frame Camera System 
Daedalus Enterprises, Inc. Of Ann Arbor, MI developed a pioneer 
complete digital aerial imaging system (Model AA455) which 
incorporated a Kodak MEGAPLUS 4.2 camera with 24 mm lens, 
a camera head control chassis, and a system recording chassis 
contained within a “lunch box” style computer. The Kodak 
MEGAPLUS 4.2 uses an array of 2029x2044 charged coupled 
devices (CCD) and a 24 mm lens, which provide a 40° Field of 
View (FOV). The system is strictly designed as an airborne 
system, therefore, it is provided with a mounting frame similar in 
size and dimension to the size and dimension of the aerial camera 
hole on the airplane. The camera has the capability to record a 
black and white (gray scale) image every 10 seconds which is the 
time required for the frame grabber to empty the signal from the 
CCD and store them on digital recording media on the airplane. 
2.2 Mission planning 
Given the 40° FOV of the lens and the fact that in 10 seconds, the 
airplane at 120 mph speed will travel the base distance (B) of 
1760 feet, the following calculation which was based on sixty 
percent end lap was possible: 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B1. Vienna 1996