Cutting Edge > Courses > GIS and Remote Sensing > Activities > Reflectance Spectra
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This page first made public: Aug 17, 2010

Reflectance Spectra

Katherine McCarville, Upper Iowa University


Students use the ALTA reflectance spectrometer to understand concepts in active vs. passive remote sensing, reflectance, and the creation and relevance of reflectance spectra.


Type and level of course
I have used this activity in an upper-division course that covers both GIS and remote sensing.

Geoscience background assumed in this assignment

GIS/remote sensing skills/background assumed in this assignment

Software required for this assignment/activity:
Excel, for data tabulation and plotting of reflectance spectra.

The ALTA reflectance spectrometer is needed. The device costs about $165. The instruction guide that ships with the device contains 10 exercises that can be adapted for use.

Time required for students to complete the assignment:
One two-hour lab period, plus time outside of class to write the lab report.


GIS/remote sensing techniques students learn in this assignment
Students learn the difference between active and passive remote sensing techniques. Students gain an understanding of the wavelengths of visible light, and the parts of the electromagnetic spectrum that are not visible to the human eye. Students create reflectance spectra for various objects, and in so doing, gain an understanding of the relevance of reflectance spectra.

Other content/concepts goals for this activity
Students practice using Excel in a practical activity.

Higher order thinking skills goals for this activity

Description of the activity/assignment

This activity results in students being able to quickly enrich their understanding of the electromagnetic spectrum, electromagnetic radiation, and the basics of remote sensing. The wavelengths used by the ALTA reflectance spectrometer are very close to the wavelengths used by Landsat, so their new knowledge transfers easily to analysis of Landsat images, and various indices, such as the NDVI.

Determining whether students have met the goals

Students move on easily to grasp the principles of image analysis, especially if they immediately begin to look at Landsat images.

Assessment of the lab report, especially the discussion questions, may also provide imformation on student achievement.
More information about assessment tools and techniques.

URLs and References

The ALTA spectrometer instruction booklet ships with the device, and contains simple forms for data capture and 10 exercises using the device.

Download teaching materials and tips

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