Getting started

Welcome to the web tutorial for Bilko v.3. The tutorial forms part of the thematic module 'Observing the Ocean from Envisat', but may also used on its own. It demonstrates the main capabilities of the Bilko v.3 software, and introduces you to data from different satellite missions - in particular four Envisat sensors, the MEdium Resolution Imaging Spectrometer (MERIS), the x xx Synthetic Aperture Radar (ASAR), the Advanced Along-Track Scanning Radiometer (AATSR) and the RA-2 Radar Altimeter.

No direct instruction is given in oceanographic image interpretation. However, by the time you reach the end of the tutorial you will already have gained some experience with marine image data. If you wish you may then continue with one or more of the eight thematic lessons in the second part of the Bilko Envisat Module.

Tutorial aims and objectives

The main aim of the tutorial is to make you familiar with the Bilko software and the principles behind some basic routines for displaying, processing and analysing remotely sensed image data. By the end of the tutorial you should be able to:

• use the Bilko help system, including context sensitive help
• open and examine the different image formats supported by the Bilko software, including the Envisat N1 format.
• use histograms to aid the interpretation and display of image data
• use different stretches to optimize image contrast and reveal features of interest
• modify, create and apply colour palettes to enhance image display
• open and work with 3-dimensional image data
• create colour composite images
• select data from single points and line transects, and use the selection to create spectra, time series plots and Hovmoller diagrams
• apply different types of filters and understand how they work with the images
• use Bilko formula documents to carry out mathematical operations on linked images
• create and apply masks
• apply geographical coordinates to gridded image data
• rectify and resample geo-referenced Envisat data
• use tables of tie-point grids or ground control points (GCPs) to rectify, resample and co-register images
• create gridded composites images using data from more than one sensor or satellite overpass
• carry out principal component analysis on time series and multi-band images.

Tutorial overview

The tutorial consists of

• this section ('Getting started') which helps you set up to use Bilko, the tutorial, the images and any other files you will need, and
• 10 tutorial sections, each of which will take you through a particular feature of the Bilko software. The Tutorial Content page gives you more details, and also provides a means of finding your way around the tutorial. You can always open the Tutorial content page by selecting the TUTORIAL link on the left sidebar.

However, we recommend that you work sequentially through the tutorial, by using the 'Next' arrows ( ) at the top and bottom of the left sidebar.

Overview of 'Getting Started'

This section is intended to

• give you some background information on the Bilko v3 software
• explain how to download, install and open it,
• advise on how to use the tutorial and the 8 thematic lessons.
• introduce you to the Bilko help system,
• and give and overview of the topics covered in the tutorial.

If Bilko is already downloaded and installed on your computer, you may wish to skip the pages dealing with how to do this, and move straight to the section called ' Using the tutorial and lessons'. This gives hints on how to get the most out of the Envisat module, and spending a few moments reading it now, may save time later.