BirdView

Introduction

BirdView is an interactive web-browser embedded application that allows users to look at the available data in the flysafe database in an easy and intuitive way. It is built using the Google Earth browser plugin, which enables it to make use of all the Google earth GIS functionality, and combine it with the ease of a webbrowser.

Requirements

To be able to use BirdView, you need to fulfill a couple of requirements. Most which are usually already installed, or in case of Google Earth browser plugin, easy to install.

• You need to run either Microsoft Windows or Maxc OS X 10.4+ as oprating system.
• You need to have a a compatible web browser. Internet explorer and Firefox are known to be compatible.
• You need to have the Google Earth plugin installed. This can be done very simply provided you have administrator rights.
• You need to have correct Video Drivers installed.
• You need to have sufficient memory. 1GB or more memory is advised.
• You need to have a sufficient high speed internet. BirdView gets its data from a central server, and so data must be transfered. A slow connection means slower refresh time.

Note: As of 21-04-2009 BirdView is not working in Internet Explorer 8. This issue is being looked at, but might be because Google Earth plugin itself is (temporarily) incompatible.

Design

The Design of the BirdView application can be divided into several different type of components, ie the HTML front-end, the Javascript interaction handling scripts, and the data serving CGI/Python scripts.

HTML Front end

The HTML front end can be found at http://public.flysafe.sara.nl/birdview.html. The reason that the front end is publicly accessible is because the browser plugin and

Control Panel

BirdView

In the BirdView tab you can find most of the interface controls for the data in the FlySafe database. Here you can easily select specific timesteps

Bounding Box

In the bounding box area you can fill in bounding values for the area that you are interested in. The visualization of the temperature, the percipitation, and the wind vectors will use these values to determine what area will be shown. The pressure level is used for those weather values that have values on different pressure levels

Bird Tracks

For each radar, an algorithm is used to extract the echoes that are considered birds. These birds are the

The low beam birds are shown in red, and the high beam birds are shown in green.

Bird summary Plot

The bird sumarry plot shows a bird density plot mapped on the speed and direction of the birds. This can be used to see the general direction of the bird migration on that particular moment.

The plot itself is made by a seperate R process, which can run preloaded R scripts. This means that other R scripts can be written that generate different kind of plots, which can be inserted in BirdView relative easily

MPR Images

The MPR images come in thre different levels:

- bottom is the full echo density image, and this is collored in a range from green to red, where red is the most dense echoes.
- The middle level is the Rain Mask, which is shown as a Blue layer.
- The top level is the Land Mask, which is shown as a Green layer.

Each layer can be turned on and off individually, in order to look at different deatails of the radar image.

Temperature

The temperature is shown as slightly transparent filled contourplot, in an area bounded by the bounding box. The temperature range displayed is light blue to dark blue for the -20 to 0 degrees celsius range, and light green-yellow-red-purple for the 0 to 40 degrees celsius range. The effect is that the zero degree boundary is easily visible because the shfit from dark blue to light green. Additionally, each level of the contour represents a step of 0.33 degrees celsius and is bordered by very thin line, that aim to help seeing different temperature layers.