Update for NASA IceBridge ATM L1B, ATM L2, and Narrow Swath ATM L1B Data

Single day Arctic data for March 25, 2015 for all three NASA IceBridge ATM products are now available from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC).

IceBridge ATM L1B Elevation and Return Strength
Data Set DOI: https://doi.org/10.5067/19SIM5TXKPGT

IceBridge ATM L2 Icessn Elevation, Slope, and Roughness
Data Set DOI: https://doi.org/10.5067/CPRXXK3F39RV

IceBridge Narrow Swath ATM L1B Elevation and Return Strength
Data Set DOI: https://doi.org/10.5067/A54HXUXMJ9UA