Overview

Cruise compilation is a complex topic and is only described here briefly.  Some InventoryManager customers use InventoryManager to export their data to 3rd party software such as TCruise or FVS for compilation. Others use InventoryManager’s in-application merchandiser/compiler, based on the National Volume Estimator Library (see details below). Still others have opted to have WSG implement custom volume equations or volume tables in InventoryManager. Your administrator should provide more detailed information on how your InventoryManager site has been configured, including the species and product groupings, taper equations (e.g., Behre's Hyperbola or Clark Profile), log rules (e.g., Scribner decimal C or International 1/4), ‘dubbing’ methods used to estimate sampled variables such as height or crown ratio, merchandising specifications (including minimum top diameter, trim, stump height, etc.) that are used for your site.

The National Volume Estimator Library section below provides more details about the InventoryManager’s merchandiser.

The Compiling a Cruise section below provides instructions below assume that all of the parameters listed above have been configured and that compilation has been tested and enabled on your production site. It also assumes that valid cruise data have been collected and thus there are stands, plots and trees that are ready to be compiled.

The Compilation Reports section below provides details about the compilation reports that can be generated by InventoryManager including the types of tables that can be produced and calculations that can performed.

National Volume Estimator Library

The National Volume Estimator Library (NVEL) is a software library developed and maintained by the US Forest Service. It implements a large number of published taper functions and volume equations. It has tools that allow access to NVEL functions within Excel and R, and the ability to call NVEL functions from various software languages such as VB and C#. More information about NVEL can be found at https://www.fs.fed.us/forestmanagement/products/measurement/volume/nvel/index.php . InventoryManager uses NVEL to apply default or user-selected equations to merchandize trees and calculate volume. It combines the field-measured values, NVEL taper equations and user-defined merchandising specs to achieve industry standard volume calculations. InventoryManager then compiles these tree level data and provides reports at the stand or sale level, allowing for a range of groupings, units, statistics, and report layouts.

Compiling A Cruise

The standard process for compiling a cruise is:

Compilation Reports

There are 5 standard tables included in the compilation capabilities in InventoryManager. These tables can be excluded or repeated in any report. For example, a given report might not include a Summary Table but might include 2 Details Tables, one for live trees and another for dead trees.

Header Table

Stand 1-Liner

Summary Table

Details Table

Calculations

The table below describes the calculations that are currently supported in the compilation tables described above. Additional calculations can typically be supported but would typically be handled via a feature request.

Calculation

Description

Stand 1-Liner

Summary Table

Details Table

Raw data

Any attribute stored at the Stand or Plot level

X

X

TPA

Trees Per Acre

X

X

X

BA

Basal Area

X

X

X

QMD

Quadratic Mean Diameter

X

Volume per acre

Volume typically board feet, cords, merchantable cubic feet. Calculated using NVEL via defaults or custom merch specs, or via custom volume equations or volume tables

X

X

X

Total volume

Same as above but multiplied by Stand acres

X

X

CV

Coefficient of Variation

X

X

AE

Achieved Error

X

Plots Required

n = t * cv / A; where: n = number of plots needed to achieve precision of A, with probability level determined by t; t = quantity from t distribution; CV = coefficient of variation, percent; A = allowable error, percent (e.g., 10%)

X

Measured Plot Count

X

Acres

X