This just in from the University of Hawaii at Manoa's Department of Geography & Environment:  HawaiiView is pleased to release the 30-m spatial resolution forest height map for the island of Oahu (https://hawaiiview.org/data/l2fhm/), predicted using Landsat-8 cloud-free mosaic and calibrated using airborne lidar data. 

The forest height map is unique in that 1) it is continuous, instead of categorical (e.g., the existing USGS products), and 2) it was calibrated using massive airborne lidar data. 

Feedback on the dataset is sought, please contact Professor Qi Chen at qichen@hawaii.edu