Tool Name	Vertical Distance to Channel Network
Tool ID	3
Library ID	ta_channels
Version	1.0
Author(s)	O.Conrad (c) 2002

Description

This tool calculates the vertical distance to a channel network base level. The algorithm consists of two major steps:
1. Interpolation of a channel network base level elevation
2. Subtraction of this base level from the original elevations

Parameters

Name	Type	Identifier	Description	Constraints
Input
Elevation	grid, input	ELEVATION	A grid that contains elevation data.
Channel Network	grid, input	CHANNELS	A grid providing information about the channel network. It is assumed that no-data cells are not part of the channel network. Vice versa all others cells are recognised as channel network members.
Output
Vertical Distance to Channel Network	grid, output	DISTANCE	The resulting grid gives the altitude above the channel network in the same units as the elevation data.
Channel Network Base Level	grid, output, optional	BASELEVEL	This optional grid output contains the interpolated channel network base level elevations.
Options
Tension Threshold	floating point number	THRESHOLD	Maximum change in elevation units (e.g. meter), iteration is stopped once maximum change reaches this threshold.	Minimum: 0.000000 Default: 1.000000
Maximum Iterations	integer number	MAXITER	Maximum number of iterations, ignored if set to zero	Minimum: 0 Default: 0
Keep Base Level below Surface	boolean	NOUNDERGROUND		Default: 1