Last Update: 27 August 2008

Help using SENTINEL

What are Layers?
UTC Explained
"Visible" Layers
Tool Buttons
Control Tabs
What are HotSpots?
HotSpot Layers
HotSpot Attributes
HotSpots by Date
System Requirements

What are Hotspots?

Hotspots are locations with a higher than normal ground temperature. Hotspots are defined with 1 km resolution channels at 4 µm and 11 µm. They are identified by flagging pixels in the satellite image where the temperature value exceeds threshold values (~300k). Both night and day MODIS passes are processed. The algorithms for identifying Hotspots are described on the MODIS Fire and Thermal Anomalies Website. Also, the specifications of the MODIS Scanner may be found on the MODIS Website.

HotSpots Layers

There are Six Layers that access the Hotspots database. Each of these layers provide a temporal view of the Hotspot information stored. It is important to recognise that the satellites pass over Australia and record only a snapshot of "part" of the continent. As a result, one should be aware of where the track of the last pass was. Fortunately this information is easily accessible through the Web. Visit the SSEC Terra Orbit Prediction Website to check up on the latest Terra and Aqua passes over Australia.

The Layers are:

MODIS NOAA Last Satellite Pass:
This view shows what the Terra or Aqua Satellite last "viewed"
Caution! This view does NOT represent the most recent National Hotspot coverage: It takes two to three passes of the satellite to "viewed" the whole of Australia. Given that all passes are received and processed by Sentinel, it takes between 2 and 24 hours to get complete continental coverage. So while this view does represent the most recent acquisition, it is important to realise that only a portion of Australia is being viewed. When this layer is viewed with the Modis Image from the same time, it becomes apparent just where the satellite was collecting the data in this layer.
MODIS NOAA Hotspots last 12 hours:
This view represents what Sentinel has collected in the "last 12 hours". Be aware that all times are UTC.
MODIS NOAA Hotspots between 12 and 24 hours:
This view represents what Sentinel has collected "between 12 and 24 hours".
MODIS NOAA Hotspots between 24 and 48 hours:
This view represents what Sentinel has collected "between 24 and 48 hours".
MODIS NOAA Hotspots between 48 and 72 hours:
This view represents what Sentinel has collected "between 48 and 72 hours".
MODIS NOAA Hotspots by Date:
Perform a search by entering a start and finish date using the "Input Boxes".

Dates are entered in the format "dd-mm-yyyy".

NOAA hotspots are detected using night time NOAA-17 and NOAA-18 passes only.

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HotSpots Attributes

There are seven attributes which can be displayed for each Hotspot using the Identify Tool

The Attributes are:

Pass Date - Time in UTC that the hotspot was detected.
Latitude - Hotspot latitude in degrees (WGS84).
Longitude - Hotspot longitude in degrees (WGS84).
Temp - Temperature estimate of the Hotspot pixel [degrees Kelvin and Celcius].
Power - An estimate of the mean radiated power of the Hotspot pixel [megawatts per square kilometre].

"MODIS Fire products - Algorithm Technical Background Document ver 2.3"

Confidence - MOD14 Firedetection algorithm indication of confidence that hotspot is a fire [0-100%].

"An Enhanced Contextual Fire Detection Algorithm for MODIS"

Satellite - Name of the satellite which detected this hotspot.

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UTC Explained

Sentinel is a continental scale project, crossing several time zones. Satellite data used in this is time stamped using Universal Time (UTC) and a 24 hour clock.

UTC is also known as GMT, or Greenwich Mean Time.
The Date and time format is written as "yyyy-mm-dd hh:mm:ss"

Use the following conversion table to convert UTC to your own local time zone.

Local time zone	Conversion from UTC	Time at 12:00 UTC
AEST - Eastern Standard Time AEDT - Eastern Daylight Savings	+10 hours +11 hours	10:00 pm 11:00 pm
ACST - Central Standard Time ACDT - Central Daylight Savings	+9.5 hours +10.5 hours	9:30 pm 10:30 pm
AWST - Western Standard Time AWDT - Western Daylight Savings	+8 hours +9 hours	8:00 pm 9:00 pm

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What are Layers?

The Sentinel Application Site is a web based portal into a Geographic Information System. The Maps you see are created by requests you make when using the controls (buttons and selectors) on the map page.

Layers are the different sets of information that can be added to your map. The web mapping system can add or subtract layers from the map according to the scale at which the map is being viewed - this stops the map becoming cluttered with lots of fine detail when large areas are being viewed.

There are several types of layers:

Map information layers: These are simply features that are common to all maps eg. coastlines, roads, rivers, town locations. They are made up of points and lines and shapes. Many of these layers can be added to the map at one time.
Images: These are digital pictures that act as backdrops to the map. They can only be displayed one at a time.
Views of data: These are layers that have been created to view a dataset in a specific way. The Layer list provided with the map interface presents several "views" of the Hotspot database. Each Hotspot layer represents a temporal search of the data that exists in the Hotspot database. These views have been provided to make it easy to search the database for recent Hotspot locations. Also provided are tools to enable the user to create their own temporal searches to query the database for historical data.

Bureau of Meteorology Layers:

These data layers are made available by the Bureau of Meteorology on a trial basis using interoperable web services (WMS and WFS). This trial system is still in the development stage at the Bureau. Although it runs on highly reliable servers, there are no redundancies catered for and no out of hours support provided at this stage. It is therefore very important to realise that this component is to allow for evaluation and testing, and that it should not be used for operational requirements.

Latest Weather Observations: Latest available weather reports of wind direction, wind speed, air temperature, dewpoint temperature, relative humidity, rainfall since 9am and barometric pressure as taken at stations making hourly or half-hourly aerodrome routine meteorological reports (METAR) or aerodrome special meteorological reports (SPECI).
Weather Watch Radar: Radar images for the detection of rain with echo intensity levels which provide an approximate indication of rainfall rate.
Wind Analysis: Wind analysis derived from the Australian Region Limited Area Prediction System (LAPS), updated four times a day for model runs at 6-hourly intervals (00, 06, 12, 18 UTC). Users comparing the wind analysis and the observations should be aware that the wind analysis is only updated four times a day whereas the observations are displaying the latest available reports taken mostly hourly or half hourly.
MSLP Analysis: Mean sea level atmospheric pressures analysis from the Australian Region Limited Area Prediction System (LAPS), updated four times a day for model runs at 6-hourly intervals (00, 06, 12, 18 UTC). Pressure readings are expressed in hecto-pascals (hPa).

Essential Services should continue to monitor
the current warnings and weather services
provided by the Bureau of Meteorology.
www.bom.gov.au

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"Visible" Layers

Making a Layer "VISIBLE"

A "Visible Layer" is a Layer that can be displayed on the map.

To make a layer "Visible", check the box

next to a layer and click the

button
To "Remove" a layer, uncheck the box

next to a layer and click the

button

Automatically refresh Map - checked to autorefresh if layer changed - unchecked must click on the button

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Tool buttons

The tool buttons are above the map display and perform the following tasks:

When selected, click on the map to center and zoom in to a point, or click and drag to select a new map extent
When selected, click on the map to center and zoom out from a point
When selected, click to center map to a point or click and drag the map with the pointer
Zooms the map to the initial extent. (Maximum zoom out)
Returns the view to the last map extent
When Selected, returns information on a features that clicked on in the map
Select to enable a distance measuring tool
Select to clear all results of a previous 'find' operation

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Control Tabs

The control tabs are above right hand frame and perform the following tasks:

"Layers" Allows selection of visible layers
"Legend" Shows legend information for layers displayed
"Find" Open "Find" page

"Zoom to State" Quick selection of single state
"Find by attribute" Find by feature type and name
"Features within buffer" Find features close to a specific feature/point
"Zoom to coordinate" Go directly to a location

"Find Results" Results page for "Find"
"Index Map" Shows location of main map
"Print" Create PDF for printing
"Help" Online Help

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System Requirements

Supported Operating Systems and Browsers:

Macintosh 9.2, OS X, OS 10.2 using MSIE v.4 - 6, Netscape v.4.7 - 7, Mozilla v.1.0
MS Windows 98, 2000, XP using MSIE v.4 - 6 or Netscape v.4.7 - 7, Mozilla v.1.0
Linux 3.0 using Mozilla v.1.0 and Galeon v.1.2.5
Solaris using Netscape v.4.7 - 7
NOTE: All other browsers have not been tested and may not correctly run the Sentinel web application.

Suggested details

The Sentinel web application works best with 15" - 800 × 600 ppi monitors or larger.

Turn Frames ON and JavaScript ON
Note: By default, your browser comes installed with Frames ON and JavaScript ON.

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