We're here to help! If you have any additional questions about accessing current or upcoming data, please contact us.
From the Download screen, click "Package Download" to package files and download a single .tar file. If any LAS or Hyperspectral files were selected, you will be prompted to select specific tiles in the "Map View" tab before being able to package the download.
You can also download files individually by clicking on the URL links shown (for LAS and other grouped files, click on [...] to expand the list of urls).
Shortcut: You can download any tile's LAS file, CHM, DTM, or Hyperspectral file directly where available by right-clicking the tile outline on the map.
Many web browsers have a maximum file download size limit. Because of this, the download packaging feature is limited to 2 GBs.
The quickest way to download large amounts of data is through an ftp software program. The list of URLs provided in the download screen can be copied and pasted into most ftp programs or command lines. Our public ftp server will be phased out in 2019.
Alternatively, we recommend saving the list of files into a new-line separated text files and using one of the following commands:
Hyperspectral datasets exceed many browser download limits. The quickest way to download these is using an FTP client. Depending on your browser and its settings, you might be able to download larger files the web browser, though it is not recommended.
If you are downloading extremely large amounts of data or experiencing bandwidth issues, we can also arrange to transfer the data onto an external hard drive you provide. Please contact us to discuss this option.
High resolution aerial photos were orthorectified and stitched together with Agisoft Metashape photogrammetry programmed. On request, we are also able to provide original photos or indvidual orthorectified photos. Aerial photography is only available for G-LiHT v.2 (2017+). We are slowly adding orthomosaics to this page, but in the meantime please visit the Aerial Photography page to see other viewing options.
Type "ortho" into the search box to find all layers with available orthomosaics. The icon indicates that the Orthomosaic overlay can be viewed for this flight by checking "Orthomosaic" in the layer control on the upper-left corner of the map.
Note: Orthomosaics are automatically generated, and results may be less than ideal. We are revising the algorithm to develop these and making continuous improvements.
Merging of time-series and multi-sensor image data is a fusion process that allows scientists to study interactions between ecosystem composition, structure and function. Equipped with this knowledge, we can better predict ecosystem responses due to land-use, disturbance, and climate change.
G-LiHT enables data fusion studies by providing coincident data in time and space, and provides fine-scale (<1 m) observations over large areas that are needed for regional ecosystem studies. Coincident, multi-sensor G-LiHT data solves a longstanding problem in data fusion studies—coregistration and analysis of data acquired at different seasons and illumination conditions, and often at different spatial resolutions.
G-LiHT Lidar, passive optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. G-LiHT data is also used to initialize and validate 3D radiative transfer models, and intercalibrate Earth observing satellites.
G-LiHT was specifically designed for use with a wide range of common, general aviation aircraft in order to provide affordable, well-calibrated image data worldwide.
G-LiHT data are typically acquired with the same instrument settings and flight parameters (e.g., flying altitude and speed); however, users are strongly encouraged to refer to the metadata and ancillary data layers for specific acquisition details. G-LiHT data are acquired for specific science applications, and some differences between campaigns will partially reflect the different strategies for data acquisition to support the science efforts.
G-LiHT data is acquired below clouds at a nominal altitude of 335 m during various times of day and sky conditions. As a result, artifacts associated with cloud shadows and variable illumination conditions may appear in the passive optical data products, particularly on days with intermittent cloud cover.
A metadata file for each acquisition selected is included with the packaged downloaded. It can also be downloaded individually from the ftp site by using the following pattern:
ftp://fusionftp.gsfc.nasa.gov/G-LiHT/ACQUISITION_NAME/ACQUISITION_NAME_metadata.txt
If there is specific information you require that is not included in the image data and metadata files, please contact us.
G-LiHT data products are created in common, user-friendly file formats that can be opened with a number of GIS and image processing software packages.
Calibrated and georeferenced data products are available in LAS (lidar point clouds); floating point GeoTIFFs (gridded lidar and thermal products); and ENVI (imaging spectrometer and ancillary products) file formats.
Google Earth quicklooks (3D trajectory; lidar CHM, DTM, apparent reflectance; NIR at-sensor reflectance; and radiant temperature) are made available as Keyhole Markup Language (KML) superoverlays.
All image data are projected in Universal Transverse Mercator (UTM), using WGS-84 and EGM96 as horizontal and vertical datum, respectively.
GIS software and online calculators can be used to convert between projections and datum.
For example, these calculators can be used to compute the difference between EGM96 and Geoid09 heights for a given location:
Lidar data returns are accurate to <1 m in the horizontal and vertical domain, based on ground control points and measured building heights. Greater accuracy would require a base station and a GPS-INS with greater accuracy. Derived canopy height and ground elevation raster products are subject to additional sampling errors associated with the distribution of lidar pulses and occlusions due to vegetation canopies and view angle.
Both the imaging spectrometer and thermal data are coregistered and orthorectified through back-projection of the lidar data. Misregistration of imaging spectrometer and thermal data to lidar data is typically <3 m, based on visual inspection of image products. Errors in coregistration are attributable to GPS-INS inaccuracies; turbulence; atmospheric effects and GPS satellite geometries; lens distortions; clock synchronization; and a combination of aircraft speed, frame rate, and focal plane array size.
Oversampling of the coarse-resolution thermal image array results in a 1 m resolution radiant temperature product that approximates 2 m smoothing (see Cook et al., 2013).
Coincident lidar, imaging spectrometer and thermal data has been collected for every G-LiHT campaign; however, many acquisitions were only funded to process and analyze the lidar data. We fully intend to process all hyperspectral and thermal data from all G-LiHT campaigns as time and resources permit.
Lidar point cloud data are saved in ASPRS LAS 1.1 format, and include:
Overlapping swaths for mapped areas have been co-aligned with coincident ground returns to remove swath-to-swath elevation biases.
Many web browsers have a maximum file download size limit. Because of this, the download packaging feature is limited to 2 GBs. If you need to use the web browser to download files, you are still able to download additional files individually by clicking on the URL link shown (for LAS and other grouped files, click on [...] to expand the list of urls). Depending on your browser and its settings, you might be able to download larger files (>2GB) such as hyperspectral data through the web browser, though it is not recommended.
The quickest way to download large amounts of data is through an ftp software program. The list of URLs provided in the download screen can be copied and pasted into most ftp programs or command lines. Our public ftp server will be phased out in 2019.
Alternatively, we recommend saving the list of files into a new-line separated text files and using one of the following commands:
If you are downloading extremely large amounts of data or experiencing bandwidth issues, we can also arrange to transfer the data onto an external hard drive you prodivde. Please contact us to discuss this option, or with any other issues regarding data download.
Radiometric calibration and spectral characterization of G-LiHT's imaging spectrometer is performed at NASA Goddard Space Flight Center, using a tunable laser light source and Spectral Irradiance and Radiance Responsivity Calibrations using Uniform Sources (SIRCUS), a system that maintains NIST-traceability via transfer radiometers.
G-LiHT lidar and thermal instruments are factory calibrated.
Lidar apparent reflectance (fraction of outgoing pulse energy in a given return) is factory calibrated and corrected for ranging distance, but not scan angle or atmospheric interactions.
At-sensor reflectance is computed as the ratio between observed upwelling radiance and downwelling hemispheric irradiance. An empirically derived multiplier is used to correct for differences in cross-track illumination and BRDF.
Ancillary data accompanying the imaging spectrometer products includes the following information for each pixel: acquisition time, aircraft location, sun-sensor geometry, incoming PAR, clearness index, swath ID, and a flag indicating nearest neighbor resampling during georegistration. “Clearness index” is computed as the ratio of observed visible irradiance to modeled irradiance under a clear sky.
Absolute values may suffer from effects of the atmospheric and variable lens and focal plane temperatures, but relative differences in temperature should be within instrument specifications for sensitivity (Noise Equivalent Temperature Difference, NETD ≥ 50 mK at 30°C). When calibrated with ground observations, differences between ground and airborne observations are approximately 1 K RMSE.
Please cite the following manuscript when referencing the G-LiHT system and data products:
Cook, B. D., L. A. Corp, R. F. Nelson, E. M. Middleton, D. C. Morton, J. T. McCorkel, J. G. Masek, K. J. Ranson, V. Ly, and P. M. Montesano. 2013. NASA Goddard's Lidar, Hyperspectral and Thermal (G-LiHT) airborne imager. Remote Sensing 5:4045-4066, doi:10.3390/rs5084045.
NASA's Earth Science Program and promotes the full and open sharing of data with all users, in accordance with NASA's Data and Information Policy.
G-Liht scientists are willing collaborators who will be able to share their scientific expertise, first-hand knowledge of the acquisitions, and unique insight on the interpretation of these data. You have the option to request collaboration and co-authorship from the G-LiHT team, but this is not mandatory to use the data.
We would appreciate notification of your publications and presentations so that we can add them to the growing list of G-LiHT citations.
We rely on data users to provide us with feedback to continually improve our data processing algorithms and higher-level G-LiHT products. If users should discover mistakes or significant anomalies in the data products, the G-LiHT science team would appreciate hearing from you.
G-LiHT is a PI-lead instrument that was designed, assembled, maintained, and flown using funds from competed research grants. We are constantly proposing and acquiring new acquisitions, motivated by NASA's Earth Science mission to understand the changing climate, its interaction with life, and how human activities affect the environment.
Please contact us if you have a compelling, well-defined science question you think G-LiHT could address as part of a future science proposal.
We also welcome hearing about targets of opportunity, i.e., sites where we might collect a small amount of data if we are operating in the area.
Please contact us if you have other questions that are not addressed here.
For more information about the G-LiHT project and current or upcoming data sets, please contact the principal investigator.
Bruce Cook, PIFor assistance using this website, to report a technical issue, or to suggest improvements, please contact the developer.
Bruce CookFrom the Download screen, click "Package Download" to package files and download a single .tar file. If any LAS or Hyperspectral files were selected, you will be prompted to select specific tiles in the "Map View" tab before being able to package the download.
You can also download files individually by clicking on the URL links shown (for LAS and other grouped files, click on [...] to expand the list of urls).
Shortcut:You can download any tile's LAS file, CHM, DTM, or Hyperspectral file directly where available by right-clicking the tile outline on the map.
Many web browsers have a maximum file download size limit. Because of this, the download packaging feature is limited to 1.5 GBs.
The quickest way to download large amounts of data is through an ftp software program. The list of URLs provided in the download screen can be copied and pasted into most ftp programs or command lines. Some information on available software can be found here:
Hyperspectral datasets exceed many browser download limits. The quickest way to download these is using an FTP client. Depending on your browser and its settings, you might be able to download larger files the web browser, though it is not recommended.
If you are downloading extremely large amounts of data or experiencing bandwidth issues, we can also arrange to transfer the data onto an external hard drive you provide. Please contact us to discuss this option.
For more information about the G-LiHT project and current or upcoming data sets, please contact the principal investigator.
Bruce Cook, PIFor assistance using this website, to report a technical issue, or to suggest improvements, please contact the developer.
Bruce CookMerging of time-series and multi-sensor image data is a fusion process that allows scientists to study interactions between ecosystem composition, structure and function. Equipped with this knowledge, we can better predict ecosystem responses due to land-use, disturbance, and climate change.
G-LiHT enables data fusion studies by providing coincident data in time and space, and provides fine-scale (<1 m) observations over large areas that are needed for regional ecosystem studies. Coincident, multi-sensor G-LiHT data solves a longstanding problem in data fusion studies—coregistration and analysis of data acquired at different seasons and illumination conditions, and often at different spatial resolutions.
G-LiHT Lidar, passive optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. G-LiHT data is also used to initialize and validate 3D radiative transfer models, and intercalibrate Earth observing satellites.
G-LiHT was specifically designed for use with a wide range of common, general aviation aircraft in order to provide affordable, well-calibrated image data worldwide.
G-LiHT data are typically acquired with the same instrument settings and flight parameters (e.g., flying altitude and speed); however, users are strongly encouraged to refer to the metadata and ancillary data layers for specific acquisition details. G-LiHT data are acquired for specific science applications, and some differences between campaigns will partially reflect the different strategies for data acquisition to support the science efforts.
G-LiHT data is acquired below clouds at a nominal altitude of 335 m during various times of day and sky conditions. As a result, artifacts associated with cloud shadows and variable illumination conditions may appear in the passive optical data products, particularly on days with intermittent cloud cover.
A metadata file for each acquisition selected is included with the packaged downloaded. It can also be downloaded individually from the ftp site by using the following pattern:
ftp://fusionftp.gsfc.nasa.gov/G-LiHT/ACQUISITION_NAME/ACQUISITION_NAME_metadata.txt
If there is specific information you require that is not included in the image data and metadata files, please contact us.
G-LiHT data products are created in common, user-friendly file formats that can be opened with a number of GIS and image processing software packages.
Calibrated and georeferenced data products are available in LAS (lidar point clouds); floating point GeoTIFFs (gridded lidar and thermal products); and ENVI (imaging spectrometer and ancillary products) file formats.
Google Earth quicklooks (3D trajectory; lidar CHM, DTM, apparent reflectance; NIR at-sensor reflectance; and radiant temperature) are made available as Keyhole Markup Language (KML) superoverlays.
All image data are projected in Universal Transverse Mercator (UTM), using WGS-84 and EGM96 as horizontal and vertical datum, respectively.
GIS software and online calculators can be used to convert between projections and datum.
For example, these calculators can be used to compute the difference between EGM96 and Geoid09 heights for a given location:
Lidar data returns are accurate to <1 m in the horizontal and vertical domain, based on ground control points and measured building heights. Greater accuracy would require a base station and a GPS-INS with greater accuracy. Derived canopy height and ground elevation raster products are subject to additional sampling errors associated with the distribution of lidar pulses and occlusions due to vegetation canopies and view angle.
Both the imaging spectrometer and thermal data are coregistered and orthorectified through back-projection of the lidar data. Misregistration of imaging spectrometer and thermal data to lidar data is typically <3 m, based on visual inspection of image products. Errors in coregistration are attributable to GPS-INS inaccuracies; turbulence; atmospheric effects and GPS satellite geometries; lens distortions; clock synchronization; and a combination of aircraft speed, frame rate, and focal plane array size.
Oversampling of the coarse-resolution thermal image array results in a 1 m resolution radiant temperature product that approximates 2 m smoothing (see Cook et al., 2013).
Coincident lidar, imaging spectrometer and thermal data has been collected for every G-LiHT campaign; however, many acquisitions were only funded to process and analyze the lidar data. We fully intend to process all hyperspectral and thermal data from all G-LiHT campaigns as time and resources permit.
Lidar point cloud data are saved in ASPRS LAS 1.1 format, and include:
Overlapping swaths for mapped areas have been co-aligned with coincident ground returns to remove swath-to-swath elevation biases.
Many web browsers have a maximum file download size limit. Because of this, the download packaging feature is limited to 2 GBs. If you need to use the web browser to download files, you are still able to download additional files individually by clicking on the URL link shown (for LAS and other grouped files, click on [...] to expand the list of urls). Depending on your browser and its settings, you might be able to download larger files (>2GB) such as hyperspectral data through the web browser, though it is not recommended.
The quickest way to download large amounts of data is through an ftp software. The list of URLs provided in the download screen can be copied and pasted into most ftp programs or command lines. Some information on available software can be found here:
If you are downloading extremely large amounts of data or experiencing bandwidth issues, we can also arrange to transfer the data onto an external hard drive you prodivde. Please contact us to discuss this option, or with any other issues regarding data download.
Radiometric calibration and spectral characterization of G-LiHT's imaging spectrometer is performed at NASA Goddard Space Flight Center, using a tunable laser light source and Spectral Irradiance and Radiance Responsivity Calibrations using Uniform Sources (SIRCUS), a system that maintains NIST-traceability via transfer radiometers.
G-LiHT lidar and thermal instruments are factory calibrated.
Lidar apparent reflectance (fraction of outgoing pulse energy in a given return) is factory calibrated and corrected for ranging distance, but not scan angle or atmospheric interactions.
At-sensor reflectance is computed as the ratio between observed upwelling radiance and downwelling hemispheric irradiance. An empirically derived multiplier is used to correct for differences in cross-track illumination and BRDF.
Ancillary data accompanying the imaging spectrometer products includes the following information for each pixel: acquisition time, aircraft location, sun-sensor geometry, incoming PAR, clearness index, swath ID, and a flag indicating nearest neighbor resampling during georegistration. “Clearness index” is computed as the ratio of observed visible irradiance to modeled irradiance under a clear sky.
Absolute values may suffer from effects of the atmospheric and variable lens and focal plane temperatures, but relative differences in temperature should be within instrument specifications for sensitivity (Noise Equivalent Temperature Difference, NETD ≥ 50 mK at 30°C). When calibrated with ground observations, differences between ground and airborne observations are approximately 1 K RMSE.
Please cite the following manuscript when referencing the G-LiHT system and data products:
Cook, B. D., L. A. Corp, R. F. Nelson, E. M. Middleton, D. C. Morton, J. T. McCorkel, J. G. Masek, K. J. Ranson, V. Ly, and P. M. Montesano. 2013. NASA Goddard's Lidar, Hyperspectral and Thermal (G-LiHT) airborne imager. Remote Sensing 5:4045-4066, doi:10.3390/rs5084045.
NASA's Earth Science Program and promotes the full and open sharing of data with all users, in accordance with NASA's Data and Information Policy.
G-Liht scientists are willing collaborators who will be able to share their scientific expertise, first-hand knowledge of the acquisitions, and unique insight on the interpretation of these data. You have the option to request collaboration and co-authorship from the G-LiHT team, but this is not mandatory to use the data.
We would appreciate notification of your publications and presentations so that we can add them to the growing list of G-LiHT citations.
We rely on data users to provide us with feedback to continually improve our data processing algorithms and higher-level G-LiHT products. If users should discover mistakes or significant anomalies in the data products, the G-LiHT science team would appreciate hearing from you.
G-LiHT is a PI-lead instrument that was designed, assembled, maintained, and flown using funds from competed research grants. We are constantly proposing and acquiring new acquisitions, motivated by NASA's Earth Science mission to understand the changing climate, its interaction with life, and how human activities affect the environment.
Please contact us if you have a compelling, well-defined science question you think G-LiHT could address as part of a future science proposal.
We also welcome hearing about targets of opportunity, i.e., sites where we might collect a small amount of data if we are operating in the area.
Please contact us if you have other questions that are not addressed here.
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Public ftp will be phased out in 2019. See: Alternate Methods
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