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Menu Bar Buttons

The menu bar is the primary way you access the functionality of the NetAssess app. It gives you access to most tools and is where you will go to download any data you wish to take from the app for further processing.

Set Area of Interest

Opens a dialog that allows you to define the area you want to examine. This will usually be the second thing you do, after selecting a parameter of interest from the dropdown to its left. The dialog that opens lets gives you several options of how to define the area of interest:

• You can define a many-sided polygon by clicking the button with the pentagon. Then each place you click on the map will become a corner of your area of interest polygon.
• You can define a rectangle by clicking the button with the square, then click and drag on the map to define opposite corners of your area of interest rectangle.
• You can select a predefined area of interest by selecting either State, CBSA, or CSA from the buttons at the bottom of the dialog. After that, the drop down will update and you can select the specific area to examine.

After you have defined your area of interest any visible monitors in that area become selected. You can now close or minimize the Area of Interest dialog. Bear in mind that some tools are restricted in the number of sites they can process so you may have to go back and select a smaller area of interest. A light blue box will appear on the screen when you attempt to run a tool with too many sites selected.

Add New Site

Allows placement of new sites. Clicking this button will cause a crosshair to follow your cursor when you are over the map. Move the cursor to where you want the new site to be located then click. The app will then use the coordinates to look up the state, county, and census tract of that location. This feature uses an external FCC REST service and may take a few seconds to complete. After it has found that information it will open a dialog. In this dialog you can give the site a name and assign parameters to be monitored.

After a new site has been added it will be treated like any other existing site when calculating area served statistics.

Calculate Area Served

Calculates the area closer to each monitor than any other monitor and adds those polygons to the map. Clicking on these polygons will open the Area Served Information window which contains geographic and demographic information, as well as exceedence probabilities when available. Clicking on the graphs will cause a new window to open with a larger version of that graph.

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View Correlation Matrix

Opens a new window in the app and displays a correlation matrix for selected monitors. This tool only works with the following parameters:

• 44201 - Ozone
• 88101 - PM2.5 Local Conditions
• 88502 - Acceptable PM2.5 AQI & Speciation Mass

The correlation matrix contains three pieces of information:

• Pearson correlation is represented by the eccentricity (flatness) of the ellipse. The flatter the ellipse, the higher the correlation.
• Average relative difference is represented by the color of the ellipse. The scale can be found in the upper right of the graph.
• Distance between monitors is displayed in the center of the ellipse, in kilometers.

You can download the correlation matrix by right-clicking on it as selecting Save image as.

Calculate Removal Bias

Estimates the concentration at each monitor's location based on surrounding monitors using an inverse distance-weighted mean, then compares it to the actual concentrations at the monitor. This tool only works with the following parameters:

• 44201 - Ozone
• 88101 - PM2.5 Local Conditions
• 88502 - Acceptable PM2.5 AQI & Speciation Mass

After you click the button new, larger circles will appear over your selected sites. The color of the circles represent the removal bias at that location. Shades of red represent positive removal bias, while shades of blue represent negative removal bias. The darker the shade, the more removal bias at that location. Refer to the legend for an explanation of the color scale.

Clicking a circle will open a popup that has detailed removal bias information for that location. This information includes:

• the minimum and maximum daily removal bias at the site,
• the mean removal bias for all available days,
• the actual date range for available data,
• and the number of monitors included in calculation.

In addition, the popup also contains relative removal bias information describes the removal bias relative to concentrations encountered at the site.

Zoom to Area of Interest

Zoom the map to your area of interest.

Zoom to Continental US

Zoom out to view the entire Continental United States.

Download Data

Open a dialog that allows you to download csv files of raw data about your area of interest.

Reset App

Reset the map to its original state. This will erase all calculations and remove any sites added to the tool.

FAQ

The entire screen has greyed out and now the tool isn't responsive, what should I do?

This indicates that the NetAssess App has lost communication with the server. This can happen if the App hasn't communicated with the server in a while, or if something has broken. Try reloading the app. If it happens again, post a comment to the issues section for the app on GitHub.

What is Removal Bias?

Removal bias is an estimate of the bias that the monitor network would have if a monitor was removed. A positive bias means that, on average, the surrounding monitors produce a higher interpolated estimate at the monitor location. A negative bias means that the interpolated estimate is lower (on average). A very small value means that there would be negligible bias if the monitor was removed.

What is Exceedance Probability?

Exceedance probability maps indicate the probability that an area will exceed a certain threshold at least one day in a year. The maps are not intended to provide probability estimates for points or areas, but should be used for a spatial comparison of extreme values.