Change search
ReferencesLink to record
Permanent link

Direct link
Spectral measurements for satellite image validation in polar and sub-polar regions
2007 (English)Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

Remote sensing has become an important tool for monitoring the Earths environment. Considerable climate changes will probably take place in the nearest future, especially around the polar areas. To be able to use satellite images of the polar regions, the atmospheres composition and the spectral properties of the ground will have to be examined. This has already been performed for large parts of the Earth, but not in the same extent in polar and sub-polar areas as in the equatorial regions. The work described in this report is a part of the Nordkalotten Satellite Evaluation co-operation Network (NorSEN). The main goal for project NorSEN is the establishing of a network for satellite data validation in the Arctic and sub-Arctic regions. For reaching this goal NorSEN includes stations for performing spectral measurements on different sites within the sub-Arctic region. One of these stations is described and evaluated here. The main purpose of this report is to process, analyse and evaluate data from ground based measurements. This, to be able to use the data in later comparison with satellite data. To perform ground based measurements a raft was placed on lake Torneträsk, which lies in the sub-Arctic region in Sweden’s northern parts, during three months in the late summer 2005. The raft was equipped with three spectrometers for measuring downwelling irradiance from the sky, downwelling radiance from a small part of the sky and upwelling radiance from a column of water in the lake. Torneträsk is a large and very clear lake with not much pollution and was therefore selected to be a possible reference surface for satellite image validation. Issues like sun glint, weather, waves, shadows and particle flows into the lake were investigated. The reflectance, i.e. the amount of incoming radiation reflected from somewhere inside the water column, was studied since it can be compared to spectral satellite data. Particle flows into the lake clearly effected the reflectance and it also differed between clear and cloudy days. The waves did not seem to effect the measurements as much as expected. But, as it was hard to determine whether the waves caused errors in the data or not, some data was excluded. To compensate for sun glint in the analysis turned out to be a complicated process, and has to be further investigated. The work in this thesis establishes a foundation for future research within satellite image validation in polar and sub-polar regions.

Place, publisher, year, edition, pages
Keyword [en]
Physics Chemistry Maths, satellite image validation, spectral measurements, polar, regions, remote sensing
Keyword [sv]
Fysik, Kemi, Matematik
URN: urn:nbn:se:ltu:diva-52575ISRN: LTU-EX--07/030--SELocal ID: 9b2457e4-324f-483a-acc8-00e2a0ea1a90OAI: diva2:1025945
Subject / course
Student thesis, at least 30 credits
Educational program
Space Engineering, master's level
Validerat; 20101217 (root)Available from: 2016-10-04 Created: 2016-10-04Bibliographically approved

Open Access in DiVA

fulltext(1906 kB)0 downloads
File information
File name FULLTEXT01.pdfFile size 1906 kBChecksum SHA-512
Type fulltextMimetype application/pdf

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

ReferencesLink to record
Permanent link

Direct link