The Japan Aerospace Exploration Agency (JAXA) releases the global digital surface model (DSM) dataset with a horizontal resolution of approx. 30-meter mesh (1 arcsec) free of charge. The dataset has been compiled with images acquired by the Advanced Land Observing Satellite "DAICHI" (ALOS). The dataset is published based on the DSM dataset (5-meter mesh version) of the "World 3D Topographic Data", which is the most precise global-scale elevation data at this time, and its elevation precision is also at a world-leading level as a 30-meter mesh version. This dataset is expected to be useful for scientific research, education, as well as the private service sector that uses geospatial information. April 2016: Version 1 covering Japan and a part of individual continent released (Total 7,278 tiles) Next release expanding area is planned around end of May 2016.

Global 25m resolutions PALSAR-2/PALSAR mosaic and forest/non-forest map are free and open dataset generated by applying JAXA's powerful processing and sophisticated analysis method/techniques to a lot of images obtained with Japanese L-band Synthetic Aperture Radars (PALSAR and PALSAR-2) on Advanced Land Observing Satellite (ALOS) and Advanced Land Observing Satellite-2 (ALOS-2). The global 25m resolutions PALSAR/PALSAR-2 mosaic is a seamless global SAR image created by mosaicking the SAR images in backscattering coefficients measured by PALSAR/PALSAR-2, where all the strip data within 10x10 degrees in latitude and longitude are path-processed and mosaicked for the sake of processing efficiency. Correction of geometric distortion specific to SAR (ortho-rectification) and topographic effects on image intensity (slope correction) are applied to make forest classification easy. The size of one pixel is approximately 25 meter by 25 meter. The temporal interval of the mosaic is generally 1 year. The global forest/non-forest map (FNF) is generated by classifying the backscattering intensity values in the global 25m resolution PALSAR-2/PALSAR mosaic so that strong and low backscatter in HV-polarization are classified "forest" (colored in green) and "non-forest" (colored in yellow), respectively. Here, "forest" is defined as the natural forest with the area larger than 0.5ha and forest cover over 90%, as same to the FAO definition. Since the radar backscatter from the forest depends on the region (climate zone), the classification of Forest/Non-forest is conducted by using the region dependent threshold of backscatter. The classification accuracy is more than 84% according to the comparison with reference data such as in-situ photos and high-resolution optical satellite images.