There are a number of ways to zoom the WebTrak Map.This is the help file for the WebTrak application. You can leave it open in your browser while you are using WebTrak for quick access to help with WebTrak's features.
What is WebTrak?
Accuracy of Flight and Track Data
Accessibility
Minimum System Requirements
Getting Help
WebTrak Map Overview
Map Navigation
Community Locator
Home Locator
Point of Approach Analysis
Displaying Static Tracks
Displaying Weather
WebTrak provides replay of aircraft operations around the immediate area of the airport for the general public. WebTrak is capable of showing both recent and past aircraft operations around the airport. It shows the path taken by aircraft and as much information about them as is permissible.
In addition to showing the aircraft operations, WebTrak is capable of showing measurements of noise taken by the airport at specific monitoring locations. These measurements can allow you to compare the noise made by aircraft operations in an area and whether particular operations have made unusual amounts of noise.
While every effort is made to ensure that the data is complete and accurate, WebTrak is not designed to be a detailed analysis system and it should not be used as such. (Please review the Terms of Use).
A number of simplifying assumptions have been made to make the display of the data to the general public practical. Data showing the current situation is captured raw and has not been subject to processing. For example aircraft tracks may look rougher when displayed on the current day. Furthermore some data sources are only available on a batch basis. These data feeds will supplement the data once nightly processing has occurred. There will be differences or corrections when nightly processing is done and the data has been reloaded into WebTrak. The historical data will always be more accurate than the current situation data due to the nightly processing of the raw data to smooth the flight tracks and address any false radar hits.
Every effort is made to ensure the completeness and accuracy of the flight and track data presented in WebTrak. However flights may be missing due to security and safety restrictions, or temporary systems failures.
In addition, due to need to support the widest possible number of communications links and computer platforms, simplifications may be made in how the data is presented. WebTrak is not suitable for detailed geographical investigations of flight data.
Due to the technologies used to provide a geospatial representation of aircraft operations at Norman Y. Mineta San Jose International, some components of this website may not be fully accessible to people with disabilities. If you cannot resolve your query using this Web site then please contact the airport directly for assistance with your specific query.
WebTrak requires Flash version 9 or later. If you have an earlier version of the plugin, WebTrak will attempt to automatically upgrade your plugin to the latest version.
The system requirements for the Flash plugin may be viewed on the Adobe Flash product information page.
To get help on items in WebTrak, try holding down the shift key on your keyboard, while clicking on an item. The help text will open for the selected item, or at the table of contents if no specific help for that item exists.
WebTrak displays a map showing the area around the airport. Over this map you will see several 'floating' panels. These panels may be dragged to new locations on the screen if they are in your way.
Click on a control name to get a detailed description of each panel:
There are a number of ways to zoom the WebTrak Map.
The zoom level bars will also show you the current zoom level. The current zoom level will be highlighted, with the rest of the bars a darker color.
Pan the map by using the pan controls situated above the zoom
buttons. The large buttons allow you to zoom North, South, East and
West.
The smaller buttons on the pan controls allow diagonal panning. These buttons allow panning North-West, North-East, South-West and South East.
When it is not possible to pan further in a direction the color of
the pan buttons will be slightly lighter. Nothing will happen if you click on
the button.
Reset the map by clicking the square in the middle of the pan controls. This will reset both the zoom and pan levels to the default view.
The map in WebTrak has a scale bar. The bar updates as you zoom in and out of the map to keep an integral number of units on its display. If the scale bar is not where you would like, it is possible to drag it out of the way by holding the left mouse button down and dragging it to where you want it.
You can use the playback controls (located by default at the bottom left of the map) to stop, start, pause, fast-forward and rewind the playback of flights.
The play button turns into a pause button when WebTrak is in play mode.
The fast-forward and rewind buttons work by changing the replay start time. To move the replay start time forward, use the fast-forward button. To move the replay start time back, use the rewind button. Note that when you click these buttons multiple times, or hold them down, the time change increases and the rate of change accelerates. Replay will begin again about a second after your last click.
If you are too close to the start of the available data, the rewind button will be disabled. If you are too close to the end of available data, the fast-forward button will be disabled.
Using the control panel you can set replay time and configure WebTrak's features.
Choose the "Live" tab and click the "Live Mode" button. To change back to a historical period, click the "Replay Mode" button, which will select the Replay tab for you so you can select a date and time.
The Replay section of the control panel contains all the options for selecting the date and time period for replay.
To select a date, click a date in the calendar. You can select a date, scroll forward or backward by month, or by year to choose a different date.
There are two ways to set the replay time.
To select the time using the time menus, simply select the time you want.
The 'Flights by Hour' graph gives you a visual display of how many flights are available for replay in each hour of the selected day. To use the 'Flights by Hour' graph, click the 'Flights by Hour' button to show the graph.
If you move your mouse over the bars in the graph you will see how many flight tracks occurred in that hour. Generally there are many more tracks than there are arrivals and departures at any one airport.
If you click a bar in the graph, the corresponding hour will be selected for you in the time dropdown menu. You may then manually select a minute if you wish.
To return to the calendar display, click the 'Show Calendar' button.
Choose a speed from the speeds drop-down if you wish to accelerate replay.
Note that on slower computers, setting the replay speed to a higher value may cause problems with playback. If you encounter problems, such as the screen not updating or your computer becoming very slow, then try a lower replay speed.
When using accelerated replay WebTrak will require additional bandwidth. For example running at ten times replay speed requires ten times the bandwidth of running the same period at normal speed. You may find that slow Internet connections are not able to support the data rates required by higher replay speeds.
Click the "Start Replay" button to start the replay at the selected time.
Info tags are small translucent panels that follow an aircraft and display information about it. The aim of the info tag is to provide a simple summary of the most important information about the aircraft. You can find out what more WebTrak knows about the aircraft by opening an information panel.
The information shown in a info tag will vary depending on what WebTrak knows about the aircraft. It may include such items as
Choose the 'Options' tab in the control panel to reveal the 'Show Info Tags' option.
Selecting the "Show Info Tags" toggle will turn Info Tags on or off.
In addition to turning on info tags for all aircraft, it is also possible to place your mouse over an individual aircraft to show its info tag.
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Clicking on an aircraft will reveal a more detailed information panel. In addition to the information contained in the tags, the information panel may contain additional information such as the name of the aircraft type, the airline, and so on. Moving your mouse over each item in the panel will reveal a tooltip about that item which will contain either more information about that data item (eg, the full name of the carrier or airport) or a description of the data item.
The information panel's title bar will display the most descriptive unique identifier available for the aircraft.
The information panel will be displayed with a line connecting it to the aircraft in question. This line will move as the aircraft moves. The panel can be moved by clicking and dragging it to a new location. Several information panels may be opened at the one time.
Information displayed in the panel depends on the information that WebTrak has available. The following table explains the information that may be seen.
| Short Name | Description |
|---|---|
| Aircraft Type | A code that identifies the basic type of the aircraft. You can use this to look up more information about the aircraft (e.g. take off weight, number of passengers, engine type etc) |
| Altitude | The vertical position of the aircraft above mean sea level. This is only the same as the height above the ground level at the aircraft's current position, if the ground level is the same as sea level. |
| Arrives | The time that the flight is expected to arrive at its destination. |
| Beacon | A number that is used by the secondary surveillance radar to distinguish the aircraft that are operating in the airspace. |
| Destination | The code used by the airlines and air traffic control for the airport where this flight is going to. It is possible to look up the code to find out specific airport details. |
| Flight Id | An identifier used by airlines and air traffic control to identify the flight. |
| Origin | The code used by the airlines and air traffic control for the airport where this flight originated. It is possible to look up the code to find out specific airport details. |
| Tail Number | A unique registration number handed out by the country where the aircraft is registered. For some countries (e.g. the US and UK) it is possible to look up the aircraft owner and details using the tail number. |
Some of the information in the tags may have a link associated with it. The
link will appear as a small world icon like this:
.
Click on the icon for more information, eg, clicking on
a link next to Aircraft Type will open another window to an online
aircraft database. From there you can search for the aircraft type for
in-depth information on the model and type of aircraft.
Remove an information panel by clicking on the 'x' on the top right hand side of the panel.
Each flight track will have a particular icon to identify it. The type of the icon varies depending on the aircraft type or purpose of the flight. This icon will also be colored, based on the operation type and airport. The following table provides the details.
| Icon | Aircraft Type | Description |
|---|---|---|
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Commercial Jet | A flight being flown by an airline using a jet aircraft. The aircraft may be carrying passengers or freight. |
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Helicopter | A flight being operated using a helicopter. Typically these will be police or emergency services. |
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Propeller aircraft | An aircraft with propellers rather than jet engines. Typically these will be smaller and slower aircraft. Often the aircraft will be operated by private individuals or corporations. |
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Unknown type | WebTrak does not have sufficient information available to classify the operator or the type of aircraft. |
Each icon will have a color assigned to determine the type of operation. Icons will be colored depending on operation (arrival/departure) type, and also the origin airport.
Each icon will have a color assigned to determine the type of operation. Icons will be colored depending on operation (arrival/departure) type, and also the origin airport.
| Color | Airport | Operation Type | |
|---|---|---|---|
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San Jose International | Arrival | |
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San Jose International | Departure | |
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Other airports | All |
The flight tracks (or tails) behind each aircraft icon will be colored depending on site configuration. In the default mode the tracks are the same color as the icon.
The airport has installed a number of Noise-Monitoring Terminals in the vicinity of the airport. The Noise-Monitoring Terminals (NMT) are used to get a measure of the noise impact caused by airport operations. The airport monitors the levels that are measured.
The human ear is able to distinguish a very wide range of noise levels. To make the numbers manageable the measurements are generally presented in decibels. You can find a long article discussing the decibels and bels on Wikipedia. Most importantly the article presents various commonly encountered noise sources and the decibel level you would expect to see for them. These comparisons will give you a feel for the noise levels that are being measured by the noise monitors and presented by WebTrak.
The noise measurements that WebTrak displays are the A-weighted sound exposure level taken over a one second period in decibels. From the point of view of using WebTrak it is the relative level of the measurements that are important.
However if you wish to explore the technical details then Wikipedia has an article explaining A-weighting and another explaining sound pressure level. From these pages you can find links to additional technical information about noise measurement.
A noise event is defined as an extended loud noise that is louder than a pre-defined level. The level is generally adjusted to match what people define as loud or 'noisy', and can change from day to night. Nights are quieter, so the 'trigger' level for a noise event may be lower. The trigger levels may also be set to take into account the background noise levels at the location. For example the threshold levels for a monitor near a busy road may be higher than in a quiet park.
The Noise and Flight Track Monitoring System classifies noise events into various ways.
| Classification | Description |
|---|---|
| Wind | The wind level is such that it is the dominant noise source |
| Aircraft | One or more aircraft appear to have made the noise event |
| Community | There appears to be no aircraft that could have caused the noise |
The noise-monitoring terminals (NMTs) measure the noise level to the nearest centibel. WebTrak simplifies its display by rounding the numbers to the nearest decibel.
NMTs are represented on the map as circles with the noise level in decibels displayed inside the circle.
In "Live" mode, the values shown are the unprocessed LAeq values collected at the NMT. The data has not been processed and classified at this time, so event information is not yet available.
In replay mode, the values shown in the NMTs are the LAE,T values that were measured during the event.
NMTs will change color, and may change shape, when a noise event is detected.
The meaning of the colors and shapes can be found in the legend below.
You must have turned on the noise-monitoring locations to see the measurements displayed. This is done by selecting the 'Show Noise Monitors' checkbox in the 'Options' tab of the control panel.
The noise monitors will be automatically turned on when in live mode.
If you move your mouse pointer over an NMT's icon on the map, you will see an info tag appear.
If you click on the NMT's icon the info tag will stay on screen after you move your mouse away from it, otherwise it will disappear when you move your mouse away. Click the NMT's icon once more to 'un-stick' the info tag.
Noise levels will cause the noise-monitor to change color gradually between the following color steps:
| Noise Level | Color | |||
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| No event |
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| 45dB to 60dB |
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| 60dB to 90dB |
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| 90dB and above |
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The Community Locator is a quick and easy way to find a particular community, area or suburb on the map.
You open the Community Locator by clicking on the community tab in the control panel.
Select the drop-down and scroll through to find the area of interest. Click on the selection and the map will pan and zoom to that area.
To reset the map to the default view, click the "Reset" button.
The Home Locator is on the Map Controls toolbar.
The home locator is the tool for identifying your home's location on the map. To use it, move your mouse to the house icon, click on the icon and holding down the mouse button drag the icon to your home's location on the map then release the mouse button to drop the icon.
If you wish to adjust the location of the house after you have placed it on the map, you may click and drag the placed icon with your mouse.
You can remove the home locator at any time by clicking on the X in the top right hand corner.
Your home location may be used for a number of functions such as providing your position for inquiry investigations or for distance of approach calculations.
The Point of Approach capability allows you to see how close aircraft get to your home location during self-investigations. You may also use it during replay to watch how the aircraft's position changes relative to your's over time.
To use the point of approach function you must set your Home Location and select an aircraft for investigation by bringing up the information panel.
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Near the bottom of the information panel you will see the Point of
Approach button.
Click on it to bring up the Point of Approach graph. The Point of Approach
graph stays connected to the selected aircraft so you can see which aircraft it
is tracking.
If you leave the replay running then the distances and angles will be updated as the aircraft moves. The two topmost items in the Point of Approach window show the time and details (slant distance and angle) of the closest approach since the Point of Approach window was first opened. You can also pause the replay to give yourself time to review the figures.
Remember that the aircraft's altitude is displayed. Altitude is relative to mean sea level and not your home location. However if you know the elevation of your home location then you can work out how high above your location the aircraft is at a particular time (the height with reference to your location). You can find more discussion of Altitude in Aviation on Wikipedia.
The static track button on the information panel allows you to review all of the track data that WebTrak has for a given flight track.
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Within the information panel you will see the Static Track button.
Click on it to load this flight's track data.
If you wish to pause replay while the static track is displayed, click the pause button in the replay controls.
Click again on the Static Track button to remove the static track display.
The weather panel shows the current weather in the vicinity of the airport.
To show, click on the show Weather checkbox in the options section of the control panel. To hide, click the close box on the weather panel, or uncheck the option in the control panel.