Aerial Photography 



High-resolution stereo-pair, aerial photographs were obtained on two 

 different occasions (Table 5) for each of the breakwaters from fixed-wing 

 aircraft. At least four monuments were established for control of each stereo 

 pair and these controls were verified or reestablished before each flight. 

 Horizontal control was based on the Hawaii State Plane Coordinate System 

 and elevations were referenced to mllw. Photographs were to be acquired 

 with a combination of camera lens and airplane elevation that would result in 

 negatives and contact prints with a minimum scale of 1 in. equal to 100 ft. 

 As seen in Table 5, all photographs met or exceeded this requirement. The 

 stereo pairs for one flight for each breakwater are shown in Figures 15-19. 



Table 5 



Listing of Stereo-Pair Aerial Photographs 



Breakwater 



Scale(s| of Negatives 



Date of Photographs 



Laupahoehoe 



6 in = 500 ft 



10 October 1991 



Laupahoehoe 



6 in = 500 ft 



n November 1992 



Kahului West 



6 in = 500 ft & 6 in = 400 ft 



19 October 1991 



Kahului West 



6 in = 500 ft 



8 January 1993 



Kahului East 



6 in = 600 ft 



19 October 1991 



Kahului East. 



6 in = 500 ft 



8 January 1993 



Photogrammetric Analysis of Armor Unit Targets 



Stereo pairs were placed in a Wild Heerburg BC3 Analytical Stereoplotter 

 and coordinates of the armor unit targets were read and recorded. These data 

 are presented in Appendix A. For each target, the following information is 

 listed: (a) date of flight, (b) survey type, (c) Northing, Easting, and Elevation 

 coordinates, (d) relative change in coordinates since last aerial flight, and 

 (e) cumulative change in coordinates since first aerial flight. In this case, 

 since only two flights have been made, relative and cumulative values are the 

 same. Data for Laupahoehoe are presented first, then East Kahului, and 

 finally, West Kahului. The purpose of the photogrammetric analyses of the 

 targets was to compare these data to data derived from ground survey work 

 (Tables 2-4) to establish the accuracy of photogrammetric work and thus give 

 validity to the detection methods that were used to ascertain armor unit 

 movement on the breakwaters. Comparisons of the September 1991 ground 

 survey data and the October 1992 aerial data are presented in Table 6 for East 

 Kahului, West Kahului, and Laupahoehoe breakwaters. Plots of these data are 



Chapter 2 Monitoring Plan and Data 



27 



