72 
larger than the actual number of records, an error message will be generated and 
the program will shut down. 
12. The analyst should load in all points from a cruise-track, including even the 
points beyond a segment’s boundary. Fixed station data collected on the date of 
a cruise-track should also be included in the file. 
13. Save this file with a descriptive title and save it in the same directory as the Inter¬ 
polator .exe. The program will only load files from its directory. 
14. Open the Interpolator and follow the radio buttons from left to right. Select 
James under Geography and chlorophyll concentration (two decimal places) 
under Parameter. Open your text file under Data Import (scroll down to see “All 
files”). The fields should populate automatically when the file is loaded. Then, 
click on Parameter Transformation and scroll down to “In”. Click on the Inter¬ 
polate button and select “2D Inverse-Distance Squared”. The defaults should not 
be altered. The program should then begin interpolating the data. 
15. Using Notepad or Excel, open the “.est” file that has been generated. This “esti¬ 
mates” file gives you the interpolator cells, by segment, and their estimated 
chlorophyll values. 
16. The “.log” file counts and lists the records used to interpolate each segment. 
STEP 4. AVERAGING THE DATA 
17. A seasonal average for a specific year should be determined by averaging the 
individual interpolations done on data culled from narrower time-frames within 
that season. For instance, the interpolations of daily cruise-tracks occurring 
between March and May 2005 should be averaged together to create an estimate 
for spring 2005. 
18. The Interpolator has a Math function that will average the interpolation cover¬ 
ages from individual “.est” files. The advantage of using this function is in its 
convenience, but there is one disadvantage: the program is inflexible when it 
comes to missing data. If one file has a missing value for a cell (which arises 
when there were no data points within the predefined search radius of that partic¬ 
ular cell), the Interpolator ignores the data contained in the other .est files for that 
cell, resulting in a missing value (-9) in the average output. The analyst may 
choose to bypass the Math function and do the cell-by-cell averaging in a spread¬ 
sheet, so that missing values can be replaced with blanks. After calculating the 
seasonal average, values that are still missing should be replaced with a null 
character, such as a period or an asterisk. 
19. If interpolations are based primarily on daily cruise-tracks, then averages should 
be calculated separately for each segment-year. For each segment, the assess¬ 
ment spreadsheet should use only the days of targeted DATAFLOW cruises, 
since these dates will provide good estimates for only the targeted segment. The 
only other interpolated dates that should be used in the assessment spreadsheet 
for a segment’s assessment are: 1) those with records for at least two fixed 
stations and 2) those in which an adjacent segment was targeted by a DFLO 
appendix g 
Chlorophyll a Assessment Protocol 
