This dataset includes Level 1B (L1B) and Level 2 (L2) data products from the MODIS/ASTER Airborne Simulator (MASTER) instrument. The spectral data were collected as part of the Westcoast & Heartland Hyperspectral Microwave Sensor Intensive Experiment (WH2yMSIE) airborne campaign during 10 flights aboard a NASA ER-2 aircraft across the central US from Arkansas to California, U.S., and along the west coast and eastern Pacific Ocean. Flights occurred from 2024-10-18 to 2024-11-13. WH2yMSIE demonstrates the first-of-its-kind hyperspectral microwave airborne measurements and is complemented by other passive (infrared, visible) and active (lidar) sensors onboard the aircraft. It serves as a future NASA planetary boundary-layer (PBL) mission prototype and aims to capture a wide variety of thermodynamic, moisture, and PBL regimes across a variety of surface types. Data products include L1B georeferenced multispectral imagery of calibrated radiance in 50 bands covering wavelengths of 0.460 to 12.879 micrometers at approximately 50-meter spatial resolution. Derived L2 data products are emissivity in five bands in thermal infrared range (8.58 to 12.13 micrometers) and land surface temperature. The L1B file format is HDF-4, and L2 products are provided in HDF-5 and KMZ formats. In addition, the dataset includes the flight path, spectral band information, instrument configuration, ancillary notes, and summary information for each flight, and browse images derived from each L1B data file.