Points / Rating Table List

Introduction

A rating is a value returned from a computation table that is stored in a data report. For example a water level data report value in feet can be used to compute the stream discharge in cubic feet per second. NovaStar supports four different types of rating tables with openings:

• Linear interpolation
• Log log interpolation
• Power Curve
• Polynomial

A rating table can be assigned to one or more points. Multiple rating tables can be added to the database for a point and are assigned for use at different time periods.

Clicking on the Points / Rating Table List menu displays the Rating Table List page. A new NovaStar system will display an empty Rating Table List. The following image illustrates the Points / Rating Table List page after a rating table has been selected in the list at the top of the page.

Rating Table Page (see full-size image)

Rating Table List

The full list of ratings tables are displayed at the top of the page.

Rating Table List (see full-size image)

Navigation, Adding, Deleting, Modifying, and Copying Rating Tables

See Application Functionality for more information about basic component functionality.

The Rating Table List page conforms to a layout similar to many data types which includes a list of data items. See List Features for more information detailing page navigation; adding, copying and deleting rating tables; and modifying existing rating tables.

Identification

Rating table identification is used to organize and describe rating tables in the system and define the computation type and rules. Each rating table must have a unique name and number. The following properties are used to identify the rating tables.

Rating Table Identification (see full-size image)

Data Label	Description
Number	Rating table number must be unique for the system. Rating table numbering does not have to be sequential. The next available rating table number is automatically assigned, but can be changed, when creating a new rating table using the Add button.
Name	Rating table name must be unique for each rating table and should describe the rating table use. If multiple rating tables are created for a point over different time periods, add a time designator to the name. Max: 100 characters.
Description	Enter additional information describing rating table. Max: 1000 characters.
Type	Select the type of rating computation. See the Rating Table Type Computation Rules Table below for more information. Linear interpolation Log log interpolation Linear interpolation with opening Log log interpolation with opening Power curve Power curve with opening Polynomial Polynomial with opening
Extrapolate	Select the computation limits of the table. If a data value exceeds the index upper limit and extrapolate is false then the rating returned is limited to the computation for the upper limit value. If extrapolate is true then the rating returned is an extrapolation of the computation for the last index value.

Rating Table Type Computation Rules

Rating Table Type	Description
Linear interpolation	Use linear interpolation to compute rating value. Data values that match an index row value return the output row value. Data values that fall between two index row values return an interpolation between the two output row values. Data values less than the table lower limit return the first output value. Data values greater than the table upper limit return the last output value when rating table extrapolation is false. Data values greater than the table upper limit return a linear extrapolation of the last two output values when rating table extrapolation is true.
Log log interpolation	Use linear interpolation of log base 10 index and output values to compute rating value. The rating table index lower limit (rating table offset) is subtracted from the data and index values before log log interpolation is computed. The USGS prefers the Log log interpolation. Data values that match an index row value return the output row value. Data values that fall between two index row values return an interpolation between the two output row values. Data values less than the table lower limit return the first output value. Data values greater than the table upper limit return the last output value when rating table extrapolation is false. Data values greater than the table upper limit return a linear extrapolation of the last two output values when rating table extrapolation is true.
Linear interpolation with opening	Use linear interpolation to compute rating value for variable openings. Data and opening values that match an index and opening row value return the output row value. Data or opening values that fall between two index or opening row values return an interpolation between the two output row values then a second interpolation between the computed rating values for the surrounding openings. Data or opening values less than the table lower limit return the first output value. Data or opening values greater than the table upper limit return the last output value when rating table extrapolation is false. Data or opening values greater than the table upper limit return a linear extrapolation of the last two output values when rating table extrapolation is true.
Log log interpolation with opening	Use linear interpolation of log base 10 index and output values to compute rating value for variable openings. The rating table index lower limit (rating table offset) is subtracted from the data and index values before log log interpolation is computed. Data and opening values that match an index and opening row value return the output row value. Data or opening values that fall between two index or opening row values return an interpolation between the two output row values then a second interpolation between the computed rating values for the surrounding openings. Data or opening values less than the table lower limit return the first output value. Data or opening values greater than the table upper limit return the last output value when rating table extrapolation is false. Data or opening values greater than the table upper limit return a linear extrapolation of the last two output values when rating table extrapolation is true.
Power curve	Use a power curve equation to compute rating value: Q = ((S - offset) **exponent) * multiplier where S is the data value and Q is the computed rating value. Data values that match an index row value return the power curve computation. Data values that fall between two index row values return the power curve computation for equation assigned to the lower index row value. Data values less than the table lower limit return the power curve computation for equation assigned to the first index row value. Data values greater than the table upper limit return the power curve computation for equation assigned to the last index row value using the last index value when rating table extrapolation is false. Data values greater than the table upper limit return the power curve computation for equation assigned to the last index row value using the data value when rating table extrapolation is true.
Power curve with opening	Use a power curve equation to compute rating value: Q = ((S - offset) **exponent) * multiplier where S is the data value and Q is the computed rating value. Data and opening values that match an index and opening row values return the power curve computation. Data or opening values that fall between two index or opening row values return the power curve computation for equation assigned to the lower index and opening row values. Data or opening values less than the table lower limit return the power curve computation for equation assigned to the first index and opening row values. Data values greater than the table upper limit return the power curve computation for equation assigned to the last index and opening row values using the last index value when rating table extrapolation is false. Data or opening values greater than the table upper limit return the power curve computation for equation assigned to the last index and opening row values using the data value when rating table extrapolation is true.
Polynomial	Use a polynomial equation to compute rating value: Q = K0 + K1*S + K2*(S**2) + K3*(S**3) +K4*S(**4) +K5*(S**5) where S is the data value and Q is the computed rating value. Data values that match an index row value return the polynomial computation. Data values that fall between two index row values return the polynomial computation for equation assigned to the lower index row value. Data values less than the table lower limit return the polynomial computation for equation assigned to the first index row value. Data values greater than the table upper limit return the polynomial computation for equation assigned to the last index row value using the last index value when rating table extrapolation is false. Data values greater than the table upper limit return the polynomial computation for equation assigned to the last index row value using the data value when rating table extrapolation is true.
Polynomial with opening	Use a polynomial equation to compute rating value: Q = K0 + K1*S + K2*(S**2) + K3*(S**3) +K4*S(**4) +K5*(S**5) where S is the data value and Q is the computed rating value. Data and opening values that match an index and opening row values return the polynomial computation. Data or opening values that fall between two index or opening row values return the polynomial computation for equation assigned to the lower index and opening row values. Data or opening values less than the table lower limit return the polynomial computation for equation assigned to the first index and opening row values. Data values greater than the table upper limit return the polynomial computation for equation assigned to the last index and opening row values using the last index value when rating table extrapolation is false. Data or opening values greater than the table upper limit return the polynomial computation for equation assigned to the last index and opening row values using the data value when rating table extrapolation is true.

User Groups

The User groups table shows the user groups currently assigned to the station. For more information, see the User Groups documentation.

User Groups Assigned (see full-size image)

Index units

Rating table index units fields describe the rating table index value data.

Rating Table Index Units (see full-size image)

Data Label	Description
Units	Index value data units (plural). Max: 100 characters.
Unit	Index value data unit (singular). Max: 100 characters.
Abbreviation	Index value abbreviated data units. Max: 100 characters.
Display digits	Number of digits to display to the right of the decimal point when index data is displayed on the rating table screens and data maps, plots and reports.
Upper Limit	Limit extrapolation if the index data value is greater than the last index value. Default: use highest rating row index value.
Lower Limit	Lowest index data value used in rating computation. A data value less than the lower limit is replaced by the lower limit before a rating computation. The lower limit is also used as the offset in the log log interpolations. Default: use lowest rating row index value.

Output units

Rating table output units fields describe the rating table output value data.

Rating Table Output Units (see full-size image)

Data Label	Description
Units	Output value data units (plural). Max: 100 characters.
Unit	Output value data unit (singular). Max: 100 characters.
Abbreviation	Output value abbreviated data units. Max: 100 characters.
Display digits	Number of digits to display to the right of the decimal point when output data is displayed on the rating table screens and data maps, plots and reports.
Upper Limit	Rating table display upper limit; does not affect rating computations. Default: use highest rating row output value.
Lower Limit	Rating plot scale lower limit. Default: use lowest rating row output value.
Plot upper limit	Rating plot scale upper limit. Default: use highest rating row output value.
Plot lower limit	Rating plot scale lower limit. Default: use lowest rating row output value.

Rating Table Rows

The Rating rows list the rating rows assigned to the rating table. When a rating table is first defined, no rating row records will be assigned to the rating table.

Rating Table Rows (see full-size image)

Editing the Rating Table Options

The following options are permitted depending on the type of rating:

Linear and LogLog Interpolation Edit

Rating Table Row Edit, Linear and LogLog (see full-size image)

Data Label	Description
Index	Point data value is matched to index.
Output	Rating value returned for index.

Linear and LogLog Interpolation with Opening Edit

Rating Table Row Edit, Linear and LogLog with Opening (see full-size image)

Data Label	Description
Index	Point data value is matched to index.
Opening	Open point data value is matched to opening.
Output	Rating value returned for index.

Power Curve Edit

Rating Table Row Edit, Power Curve (see full-size image)

Data Label	Description
Power curve	Q = ((S - Offset) **Exponent) * Multiplier
Index	Point data value is matched to index.
Multiplier	Multiplier term in equation.
Offset	Offset term in equation.
Exponent	Exponent term in equation.

Power Curve with Opening Edit

Rating Table Row Edit, Power Curve Opening (see full-size image)

Data Label	Description
Power curve	Q = ((S - Offset) **Exponent) * Multiplier
Index	Point data value is matched to index.
Opening	Open point data value is matched to opening.
Multiplier	Multiplier term in equation.
Offset	Offset term in equation.
Exponent	Exponent term in equation.

Polynomial Edit

Rating Table Row Edit, Polynomial (see full-size image)

Data Label	Description
Polynomial	Q = K0 + K1*S + K2*(S**2) + K3*(S**3) +K4*S(**4) +K5*(S**5)
Index	Point data value is matched to index.
K0-K5	K0 - K5 term in equation.

Polynomial with Opening Edit

Rating Table Row Edit, Polynomial with Opening (see full-size image)

Data Label	Description
Polynomial	Q = K0 + K1*S + K2*(S**2) + K3*(S**3) +K4*S(**4) +K5*(S**5)
Index	Point data value is matched to index.
Opening	Open point data value is matched to opening.
K0-K5	K0 - K5 term in equation.

The buttons above the table perform the following functionality:

Button	Action
Print	Display the rating table rows. See the Rating Table Print section.
Plot	Plot the rating table rows. See the Rating Table Plot section.
Import	Import a rating table from a CSV file. See the Rating Table Import section.
Add	Opens the edit panel where parameters can be entered for a new record.
Delete Selected	Deletes all rows in the rating table with a checked checkbox in the left column

Rating Table Print

Not yet implemented.

The table horizontal index is set by the rating table index display digits. Table row entries are starred. Non-starred entries are interpolated.

Rating Table Plot

Rating Table Plot (see full-size image)

Rating Table Import

To import a rating table from the Rating Table Edit page, click Import above the Rating row table. The file upload window is opened. A file will be uploaded from the computer file system to the NovaStar file system. Rating import files must be CSV files with entries in the following order depending on the rating table type, see the following table.

Rating Table Type	Import File Format
Linear interpolation	index, output
Log log interpolation	index, output
Linear interpolation with opening	index, opening, output
Log log interpolation with opening	index, opening, output
Power curve	index, multiplier, offset, exponent
Power curve with opening	index, opening, multiplier, offset, exponent
Polynomial	index, K0, K1, K2, K3, K4, K5
Polynomial with opening	index, opening, K0, K1, K2, K3, K4, K5

Rating Table Delete

To delete a rating table from the Rating Table List, select the rating table, click Edit and then click Delete. The page prompts again with a popup to confirm the deletion. If a rating table is deleted, the record of that rating computation will be lost, which describes how data report ratings were computed for the assignment time period. Deleting the rating tables will not remove rating values already computed and stored in the point data reports.