1971 AIDJEX pilot study: An emissometer was used by CRREL-USGS-AEROJET to measure microwave emissivity of sea ice (Far right W. Campbell) Image Credit:  National Snow &amp; Ice Data Center <a href="http://nsidc.org/data/aidjex/">AIDJEX Web site</a> (<a href="/cryosphere/gallery/photo/33467">View photo detail.</a>) <br>