D-27 
Line 3>Cell centroid easting in meters, cell centroid northing in meters, number of cells (>0) from 
surface to bottom, cell centroid depths from surface to bottom. The Interpolator computes a value for 
each cell centroid identified in the .bth file which is output to the .est file. 
(Repeat 2 & 3 for each segment.) 
8 
132.1001. CB1TF, 1000,1000.1 
403000,4384000.2,0.5,1.5 
404000.4384000,5,0.5.1,5.2.5.3.5,4.5 
404000,4383000.3,0.5,1.5,2.5 
405000,4383000,8.0.5,1.5,2.5,3.5,4.5.5.5.6.5,7.5 
405000.4382000.3,0.5,1.5,2.5 
410000.4363000,6.0.5,1,5.2.5.3.5.4.5,5.5 
411000,4363000.10,0.5,1.5.2.5,3.5,4.5,5.5,6.5,7.5,8.5,9.5 
412000,4363000,4.0.5.1,5,2.5,3.5 
270.1002. CB20H, 1000,1000,1 
403000.4363000.3,0.5.1.5.2.5 
404000,4363000.4,0.5.1,5,2.5,3.5 
405000.4363000,3,0.5.1.5,2.5 
406000,4363000.3,0.5.1.5,2.5 
400000.4362000,1,0.5 
385000.4107000,1.0.5 
381000,4106000,2,0.5,1.5 
381000,4105000,2,0.5,1.5 
381000.4104000,1.0.5 
DATA REGIONS FILES (regions.sys, .reg) 
Each interpolator job requires a data regions file which defines the geographic 
boundary of the data for the body of water that is being interpolated. 77 data regions 
have been created, one for each CBP segment. The data region is used to clip off data 
that fall outside the desired geographic area that is being interpolated. A data regions 
file includes one or more data region definitions that must match the bathymetry 
being interpolated. These data region file names are stored in a file, regions.sys, 
which is required by the Interpolator. This file can contain 25 defined regions files. 
The order of the entries in this file define the order presented to the user in the 
GEOGRAPHY screen during the job. The structure of the regions.sys file is: 
Line l+>Item identifier (sequential number of 1 to 25). comma, data region name, comma, 
corresponding bathymetry file name, comma, corresponding data region file name. 
Repeat for each defined data region. 
1. Bay and Tribs.bay_trib.bth,bay_trib.reg 
2, Chesapeake Mainstem (CB ICB8),cbay8.bth,cbay8.reg 
Each .reg file defined in the regions.sys file must have the following structure. The following shows the 
contents of the cbay8.reg file: 
Line l>Bathymetry file name 
appendix d 
User Guide and Documentation for the Chesapeake Bay Interpolator 
