that other users need only make minor or no chanqes to their 

 hardware and software for data capture (see Appendix D). 



5.7 MISSION LENGTH 



In order to conduct in the iin situ field work necessary to exploit the 

 ocean color observations from space, experiments listed earlier must be 

 staged in a variety of seasons and conditions. Logistically, this implies 

 that the spacecraft mission must cover at least two years to specify 

 atypical situations, e.g., the occurrence of El Nino phenomena. In addi- 

 tion, even the coarsest values for ranges in interannual productivity are 

 not known for most ocean areas. An absolute minimum of two years of 

 observation is necessary to identify the scale of variability. Thus, a 

 minimum mission length of two years is required, with any extension of that 

 length highly desirable. That also implies that instrument calibration be 

 constant, or identifiable, during the minimum two-year mission to allow 

 valid comparisons of ocean observational values. 



5-9 



