Wednesday, March 10, 2010 8:00 GMT 
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Tutorial for Recon in Google Earth


This tutorial is about our aircraft reconnaissance product for Google Earth. When a mission is active, or for missions we have archived, you will find some of the following symbols, all of which are clickable.

A round white circle with a number in it represents a vortex message with the pressure, in millibars, located in the circle. You can click this icon to view a decoded vortex message which contains mostly information about the center of the storm.
This is a picture of a dropsonde. A dropsonde is released from the aircraft to sample such things as wind, temperature, and pressure. You can click this icon to view a decoded dropsonde message, which contains the previous mentioned things at different levels between the aircraft and sea surface. A dropsonde diagram is also available in the popup window which displays most of the data in the tables in a visual way.
A pair of binoculars represent a RECCO message, a "REConnaissance COde" message, which has information that is observed by a person onboard the plane. You can click this icon to view a decoded RECCO message.
HDOB messages are usually transmitted every 30 seconds. For each observation within an HDOB message, usually there are 20 observations per HDOB message, you will see a wind barb that represents wind direction and speed. Learn about how to decode a wind barb here. The winds barbs to the left, from left to right, represent 5 knots, 10 knots, and 65 knots. All of them note that the wind direction is from 0 degrees, or from the north. It means that if you were facing north, the wind would be hitting you in the face. Wind speed is also noted by color for our recon product in Google Earth.

In addition to decoding a wind barb to determine the wind speed, you can also identify the wind speed, in knots, by color. This is the legend you will see in the top left corner of Google Earth:



If you ever see a mission with only dropsondes available it is likely a NOAA Gulfstream IV-SP mission. This G-IV aircraft flies at very high altitude sampling the atmosphere around a storm, often well away from the storm, and does not take observations inside the storm like other reconnaissance missions. The plane does not report HDOB messages so the path of the aircraft is not currently shown in our system. I might change that eventually.

This is an example of what the menu in the left column will look like. One the Google Earth network link opens, "Do not display any missions" will be selected. This is because I don't want to use bandwidth loading a mission you may not want to view. When there are multiple storms, it would be a waste of bandwidth to load a mission for a storm you don't want to view mission data for. Once you select the mission you want, like "Mission 02 into Gustav" in the example at the left, that network link will open the data for that mission. The storm number will be located in parenthesis next to the storm name. Under that you will find the mission number. Next to that you will find the agency that is investigating the storm, "AF" for Air Force and "NOAA" for the National Oceanic and Atmospheric Administration. The number to the right of the agency is the tail number of the aircraft.

The other folders contain information on different observations. You can check a folder to show or hide all observations of that type. When you expand a folder you will be able to view all the observations of that type. From there you can select to show or hide specific observations. For HDOB messages, observations are noted by the message number, like "OB 01", which is the observation number for a set of observations, usually 20.

To view the latest position of the reconnaissance aircraft, look for the picture of a plane. If you click the icon, you will see the direction the plane is traveling and the distance to a predefined list of large cities.

Missions from the past three hours can be found in our Google Earth network link. Past missions can be found in our recon archive. Look for the Google Earth symbol ( ) in the archive to view mission data for an archived mission.


< Return to our main recon page.


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