![JAXA/ALOS/PALSAR/YEARLY/SAR](https://developers.google.com/earth-engine/datasets/images/JAXA/JAXA_ALOS_PALSAR_YEARLY_SAR_sample.png) Dataset Availability : 2007-01-01T00:00:00Z--2020-01-01T00:00:00Z Dataset Producer : [JAXA EORC](https://www.eorc.jaxa.jp/ALOS/en/dataset/fnf_e.htm) Tags : [alos](https://developers.google.com/earth-engine/datasets/tags/alos) [alos2](https://developers.google.com/earth-engine/datasets/tags/alos2) [eroc](https://developers.google.com/earth-engine/datasets/tags/eroc) [jaxa](https://developers.google.com/earth-engine/datasets/tags/jaxa) [palsar](https://developers.google.com/earth-engine/datasets/tags/palsar) [palsar2](https://developers.google.com/earth-engine/datasets/tags/palsar2) [sar](https://developers.google.com/earth-engine/datasets/tags/sar) [satellite-imagery](https://developers.google.com/earth-engine/datasets/tags/satellite-imagery) #### Description A newer version of this dataset with data for 2015-2021 can be found in [JAXA/ALOS/PALSAR/YEARLY/SAR_EPOCH](https://developers.google.com/earth-engine/datasets/catalog/JAXA_ALOS_PALSAR_YEARLY_SAR_EPOCH) The global 25m PALSAR/PALSAR-2 mosaic is a seamless global SAR image created by mosaicking strips of SAR imagery from PALSAR/PALSAR-2. For each year and location, the strip data were selected through visual inspection of the browse mosaics available over the period, with those showing minimum response to surface moisture preferentially used. In cases where the availability was limited (e.g., because of the requirement for observations during specific emergencies), data were necessarily selected from the year before or after, including from 2006. [Shimada et al. 2014](https://doi.org/10.1016/j.rse.2014.04.014) There is no data for 2011-2014 due to the gap between ALOS and ALOS-2 temporal coverage. The SAR imagery was ortho-rectificatied and slope corrected using the 90m SRTM Digital Elevation Model. A destriping process (Shimada \& Isoguchi, 2002, 2010) was applied to equalize the intensity differences between neighboring strips, occurring largely due to seasonal and daily differences in surface moisture conditions. Polarization data are stored as 16-bit digital numbers (DN). The DN values can be converted to gamma naught values in decibel unit (dB) using the following equation: - γ₀ = 10log₁₀(DN²) - 83.0 dB Attention: - Backscatter values may vary significantly from path to path over high latitude forest areas. This is due to the change of backscattering intensity caused by freezing trees in winter. More information is available in the provider's [Dataset Description](https://www.eorc.jaxa.jp/ALOS/en/palsar_fnf/DatasetDescription_PALSAR2_Mosaic_FNF_revH.pdf). ### Bands **Bands** Pixel size: 25 meters (all bands) | Name | Units | Pixel Size | Description | |---|---|---|---| | `HH` | | 25 meters | HH polarization backscattering coefficient, 16-bit DN. | | `HV` | | 25 meters | HV polarization backscattering coefficient, 16-bit DN. | | `angle` | deg | 25 meters | Local incidence angle. | | `date` | | 25 meters | Observation date (days since Jan 1, 1970). | | `qa` | | 25 meters | Processing information. | **qa Class Table** | Value | Color | Description | |---|---|---| | 0 | #000000 | No data | | 50 | #0000ff | Ocean and water | | 100 | #aaaa00 | Radar layover | | 150 | #005555 | Radar shadowing | | 255 | #aa9988 | Land | ### Terms of Use **Terms of Use** JAXA retains ownership of the dataset and cannot guarantee any problem caused by or possibly caused by using the datasets. Anyone wishing to publish any results using the datasets should clearly acknowledge the ownership of the data in the publication. ### Citations Citations: - Masanobu Shimada, Takuya Itoh, Takeshi Motooka, Manabu Watanabe, Shiraishi Tomohiro, Rajesh Thapa, and Richard Lucas, "New Global Forest/Non-forest Maps from ALOS PALSAR Data (2007-2010)", Remote Sensing of Environment, 155, pp. 13-31, December 2014. [doi:10.1016/j.rse.2014.04.014.](https://doi.org/10.1016/j.rse.2014.04.014) ### Explore with Earth Engine > [!NOTE] > **Important:** Earth Engine is a platform for petabyte-scale scientific analysis and visualization of geospatial datasets, both for public benefit and for business and government users. Earth Engine is free to use for research, education, and nonprofit use. To get started, please [register for Earth Engine access.](https://console.cloud.google.com/earth-engine) ### Code Editor (JavaScript) ```javascript var dataset = ee.ImageCollection('JAXA/ALOS/PALSAR/YEARLY/SAR') .filter(ee.Filter.date('2017-01-01', '2018-01-01')); var sarHh = dataset.select('HH'); var sarHhVis = { min: 0.0, max: 10000.0, }; Map.setCenter(136.85, 37.37, 4); Map.addLayer(sarHh, sarHhVis, 'SAR HH'); ``` Python setup See the [Python Environment](https://developers.google.com/earth-engine/guides/python_install) page for information on the Python API and using `geemap` for interactive development. ```python import ee import geemap.core as geemap ``` ### Colab (Python) ```python dataset = ee.ImageCollection('JAXA/ALOS/PALSAR/YEARLY/SAR').filter( ee.Filter.date('2017-01-01', '2018-01-01') ) sar_hh = dataset.select('HH') sar_hh_vis = {'min': 0.0, 'max': 10000.0} m = geemap.Map() m.set_center(136.85, 37.37, 4) m.add_layer(sar_hh, sar_hh_vis, 'SAR HH') m ``` [Open in Code Editor](https://code.earthengine.google.com/?scriptPath=Examples:Datasets/JAXA/JAXA_ALOS_PALSAR_YEARLY_SAR) [Global PALSAR-2/PALSAR Yearly Mosaic, version 1](https://developers.google.com/earth-engine/datasets/catalog/JAXA_ALOS_PALSAR_YEARLY_SAR) A newer version of this dataset with data for 2015-2021 can be found in JAXA/ALOS/PALSAR/YEARLY/SAR_EPOCH The global 25m PALSAR/PALSAR-2 mosaic is a seamless global SAR image created by mosaicking strips of SAR imagery from PALSAR/PALSAR-2. For each year and location, the strip data were selected through visual inspection of the ... JAXA/ALOS/PALSAR/YEARLY/SAR, alos,alos2,eroc,jaxa,palsar,palsar2,sar,satellite-imagery 2007-01-01T00:00:00Z/2020-01-01T00:00:00Z -90 -180 90 180 Google Earth Engine https://developers.google.com/earth-engine/datasets - [](https://doi.org/https://www.eorc.jaxa.jp/ALOS/en/dataset/fnf_e.htm) - [](https://doi.org/https://developers.google.com/earth-engine/datasets/catalog/JAXA_ALOS_PALSAR_YEARLY_SAR)