AVIRIS and Remote Sensing

by

Kevin Faurot


Table of Contents
Abstract
Introduction
About AVIRIS
AVIRIS Instrument
Conclusion
References

Abstract

Remote Sensing today utilizes numerous instruments and state of the art technology to give users the best results possible. One of the best instruments in use today is AVIRIS. This webpage is designed to give a basic overview of what AVIRIS is and how it is used in the field of Remote Sensing.

Introduction

AVIRIS is an acronym for Airborne Visible InfraRed Imaging Spectrometer. The instrument is state of the art using 224 bands of spectral radiance to deliver a well calibrated image. These bands cover a wavelength range from 400 to 2500 nanometers. AVIRIS is used to "identify, measure and monitor constituents of the Earth's surface and atmosphere based on molecular absorption and particle scattering signatures" (AVIRIS Homepage, 2005).The concentration of the AVIRIS project is to understand and observe climate change and the global environment.


Image taken from:
AVIRIS Homepage.


About AVIRIS

With AVIRIS using 224 different bands a very broad range is covered with each band covering about 10 nanometers. That is what gives this instrument a wavelength range from 400 to 2500 nanometers. With this information the bands are plotted onto a graph creating a spectrum which is then compared to known substances and this information is used to determine the surface being viewed.

The AVIRIS instrument has been used on two different aircrafts. The first of these is the NASA ER-2 which is an aircraft that flies about 20km above sea level and 730km/hr. The other aircraft is the Twin Otter that flies 4km above sea level and at a speed of 130km/hr. The area covered by AVIRIS includes the entire United States and parts of Canada and Europe.All information obtained during a flight is recorded on board the instrument. "When all of this data is processed and stored on the ground, it yields approximately 140 Megabytes (MB) for every 512 scans (or lines) of data. Each 512 line set of data is called a "scene", and corresponds to an area about 10km long on the ground" (AVIRIS Homepage, 2005).

AVIRIS Instrument


Image taken from:
Remote Sensing Tutorial Section 13.


- 17 Mbps data rate through 1994, 20.4 Mbps from 1995
- 10 bit data encoding through 1994, 12 bit from 1995
- Silicon (Si) detectors for the visible range, and indium-antimonide (InSb) detectors for the near infrared
- "Whisk broom" scanning
- 12 Hz scanning rate
- Liquid Nitrogen (LN2) cooled detectors
- 10 nm nominal channel bandwidth, calibrated to within 1 nm
- 30 degrees total field of view (full 614 samples)
- 1 milliradian Instantaneous Field Of View (IFOV, one sample), calibrated to within 0.1 mrad
- 35GB DLT tape IV recording medium

Table information obtained from:
AVIRIS Homepage.

Conclusion

The AVIRIS instrument is an amazing state of the art tool used for the continued research and observation of Earth and its systems With AVIRIS using 224 bands a large wavelength range can be covered giving some of the best coverage and images found in Remote Sensing today. The instrument covers a 400 to 2500 nanometer range in wavelength creating a spectrum that is put onto a graph and then compared to other information to determine the characteristics of the surface observed. AVIRIS is an instrument that is carried by aircraft at low altitudes where numerous scans are made by the instrument to obtain the data. Once 512 scans are made they are collaborated together to form what is known as a "scene" which covers an area approximately 10km long. This instrument is excellent for observing, identifyin, measuring and monitoring the Earth's surface and its signatures.

Refernces

AVIRIS Homepage Web Site. Updated 10/9/05
http://aviris.jpl.nasa.gov/html/aviris.overview.htmlAccessed 12/3/05

Remote Sensing Tutorial Web Site. Update unknown
http://www.fas.org/irp/imint/docs/rst/Sect13/Sect13_9.htmlAccessed 12/3/05


This site was created on December 3, 2005 by Kevin Faurot for ES 771 a Remote Sensing course at Emporia State University.
Contact me at four_oh_phi434@hotmail.com.
Copyright 2005 Kevin Faurot. All rights reserved.

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