Full text: Proceedings, XXth congress (Part 5)

   
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occupation of around 1300AD and an abandonment 300 years 
later. Shortly after that, people returned to this area, and under 
the hand of Spanish religious leaders, the native peoples built 
the mission church, Za Purísima Concepción. The church was 
erected in the early 1630's and in use for approximately 40 
years (Wilson, 1993; Gifford, 1988). The ruins include nearly 
complete walls, up to 12 meters in height that still show the roof 
beam support holes. The church was built so as to be attached 
to the existing pueblo (Figure | and 2). Although the entire site 
will need to be documented, this experiment focused on the 
church itself because of it’s size and current state of 
preservation. 
  
Figure 1. Mission church, La Purisima Concepciôn, associated 
with the Quarai pueblo ruins of Salinas National Monument. 
Quarai pueblo ruins group and the associated mission church, La Purisima Concepción (highlighted), 
in the Salinas Pueblo Missions National Monument 
  
  
0 5 10 15 20 25 meters 
Figure 2. Map of the Quarai pueblo ruins'of Salinas National 
Monument. 
2. TOOLS AND METHODS 
The methods employed for this process are unique to the 
photographic equipment that was employed. Technological 
advances are making digital photography a viable alternative 
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part BS. Istanbul 2004 
for documentation. Digital photogrammetry is more accessible 
due to advancements in and availability of the software. This 
section will discuss the tools used for this documentation 
experiment and the methods developed to utilize these tools. 
2.1 Tools 
Two cameras were used in this project, one in each application. 
The camera used for the first experiment was a Nikon 990 with 
an FC-ES8 fish-eye lens. The Nikon 990 is capable of capturing 
images at a maximum resolution of 2048 x 1336, or 3.2 
effective megapixels. The FC-E8 lens has a viewing angle of 
183 degrees, magnification of 0.209x and an 8mm focal length. 
This provided the ability to capture a larger area without having 
to take multiple pictures, allowing the reduction of person- 
hours in recording and processing images. The second 
experiment utilized a slightly newer model of camera and lens, 
the Nikon Coolpix 5700 and the Nikon Fish-eye lens FC-E9. 
The Nikon 5700 has a resolution of 2560 x 1920 pixels, or 5 
megapixels, and the FC-E9 features approximately 183-degree 
coverage with a focal length of 7mm and magnification of 0.2x. 
These cameras were chosen for the high-resolution capability 
necessary for detail in documentation. 
The photogrammetric software used in the project was 
PhotoModeler Pro 4.0 by EOS Systems, Inc. This was used to 
perform the camera calibrations and to conduct the digital 
photogrammetric processing. It is an affordable, readily 
available off-the-shelf software package. 
2.2 Methods 
The process of the digital photo documentation involved three 
stages. The first involved calibrating the camera and lens to the 
digital photogrammetric software that was to be employed. The 
second stage was to acquire the images, and the third was to 
digitally process them in the photogrammetric software 
computer program. 
2.2.1 Camera Calibration: The calibration of the camera to 
the PhotoModeler software was necessary to remove the 
distortions that are inherent in the lens. This process was 
particularly important for this experiment, as it was necessary to 
also remove the extreme distortion caused by the fish-eye lens. 
This particular type of lens had never been utilized with this 
software before, and therefore a full calibration had to be made. 
which involved some intervention on the user’s part to 
manipulate the calibration software to see what it was unable to 
register. This process had to be performed twice, as two 
different sets of cameras and lenses were used in the project. 
2.2.2 Image Acquisition: The digital photographs were 
acquired by mounting the camera on a tripod at a height of 
approximately four feet. Because the fish-eye lens captures 
large areas horizontally and vertically, the photographer can 
capture whole walls from a near-ground level, making elevation 
of the camera and operator unnecessary. The photos had to be 
taken sequentially along a wall if the structure was too long to 
fit into a single image. The images also had to be overlapping 
by approximately 60% to allow photogrammetric processing. 
   
    
    
   
  
    
   
   
       
     
     
  
  
  
  
  
  
  
  
  
   
   
    
   
  
   
  
   
     
    
  
  
  
   
    
      
   
    
   
  
  
   
     
   
  
   
   
     
   
	        
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