Current Browsing: visible remote sensing


The Landsat ETM+ images of Heihe River Basin (1999-2008)

In April 1999, Landsat 7 was launched. As a supplement and enhancement to the Landsat series, the sensor it carried was ETM+. The parameters of each band were close to those of Landsat 5, but the resolution of panchromatic band with a resolution of 15m was added, and the resolution of thermal infrared band was improved to 60m. At present, there are 85 ETM + data scenes in heihe river basin.Data acquisition time is 1999-07-07, 1999-09-23 (2 scenes), 1999-10-18, 1999-11-26, 2000-01-20, 2000-04-20, 2000-05-06 (2 scenes), 2000-05-20, 2000-06-14 (2 scenes), 2000-07-07 (2 scenes), 2000-07-08, 2000-08-10, 2000-10-02, 2000-10-11,2000-10-13, 2001-05-25, 2001-07-03, 2001-08-20 (2 king), 2001-10-23, 2002-05-03, 2002-05-28, 2002-06-13, 2002-06-29, 2002-07-24, 2004-12-11, 2005-07-23, 2005-09-09, 2005-10-09, 2006-05-07,2006-05-21, 2006-06-24, 2006-07-26, 2006-08-25, 2006-12-01, 2007-08-12, 2008-01-05, 2008-02-06, 2008-03-25, 2008-05-10, 2008-05-19, 2008-05-28, 2008-06-04, 2008-07-15 (2 scenes), 2008-07-22, 2008-08-16 (4 scenes),2008-08-30, 2008-09-08, 2008-09-15, 2008-09-17, 2008-10-01, 2008-10-10 (2 scenes), 2008-10-19 (3 scenes), 2008-10-26 (3 scenes), 2008-11-02, 2008-11-04 (4 scenes), 2008-11-18, 2008-11-20 (4 scenes), 2008-11-27 (3 scenes), 2008-12-04, 2008-12-062008-12-13 (3 scenes).

2020-06-05

Landsat ETM remote sensing dataset in Western China

This dataset includes: remote sensing data _ETM around 2000 in Western China; Data attributes: Pixel Size: 15-meter panchromatic: Band 8                 30-meter: Bands 1-5 and Band 7                 60-meter: Bands 6H and 6L Resampling Method: Cubic Convolution (CC) Map Projection: UTM – WGS 84 Polar Stereographic for the continent of Antarctica. Image Orientation: Map (North Up) The data was downloaded from USGS: http://glovis.usgs.gov/ImgViewer/Java2ImgViewer.html?lat=38.3&lon=78.9&mission=LANDSAT&sensor=ETM. Part of the remote sensing images collected from various research projects. The folder contains ETM 8 band images (* .tif) and header files (* .met). The naming format of image files is row and column number _ETM image logo (7k, 7x, 7t), image acquisition time _ image 6 degree band number _ band number. The data also includes an image index map in shp format.

2020-06-04

The NPP products of MODIS in Sanjiangyuan (1985-2015)

The data set contains NPP products data produced by the maximum synthesis method of the three source regions of the Yellow River, the Yangtze River and the Lancang River. The data of remote sensing products MOD13Q1, MOD17A2, and MOD17A2H are available on the NASA website (http://modis.gsfc.nasa.gov/). The MOD13Q1 product is a 16-d synthetic product with a resolution of 250 m. The MOD17A2 and MOD17A2H product data are 8-d synthetic products, the resolution of MOD17A2 is 1 000 m, and the resolution of MOD17A2H is 500 m. The final synthetic NPP product of MODIS has a resolution of 1 km. The downloaded MOD13Q1, MOD17A2, and MOD17A2H remote sensing data products are in HDF format. The data have been processed by atmospheric correction, radiation correction, geometric correction, and cloud removal. 1) MRT projection conversion. Convert the format and projection of the downloaded data product, convert the HDF format to TIFF format, convert the projection to the UTM projection, and output NDVI with a resolution of 250 m, EVI with a resolution 250 m, and PSNnet with resolutions of 1 000 m and 500 m. 2) MVC maximum synthesis. Synthesize NDVI, EVI, and PSNnet synchronized with the ground measured data by the maximum value to obtain values corresponding to the measured data. The maximum synthesis method can effectively reduce the effects of clouds, the atmosphere, and solar elevation angles. 3) NPP annual value generated from the NASA-CASA model.

2020-06-03

MODIS vegetation index dataset in Sanjiangyuan (2000-2018)

The data set is MODIS vegetation index data (MOD13Q1). The source areas of the three rivers are extracted to carry out the research and analysis of the source areas of the three rivers separately. MOD13Q1 is a 16-day composite vegetation index, including normalized vegetation index (NDVI) and enhanced vegetation index (EVI). The spatial scope of Sanjiang Source covers two MODIS files (h25v05 and h26v05). Data storage format is hdf. Each file contains 12 bands: Normalized Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Data Quality (VI Quality), Red Reflectance, Near Infrared Reflectance (NIR Reflectance), Blue Reflectance, Mid Infrared Reflectance, Observation. Viewzenith angle, sun zenith angle, relative azimuth angle, composite day of the year and pixel reliability. The data format of this data set is hdf, spatial resolution is 250m, temporal resolution is 16 days, time range: February 2000 to October 2018.

2020-06-03

Spot vegetation NDVI dataset for Sanjiangyuan (1998-2013)

The data set is extracted from the NDVI data of long time series acquired by VEGETATION sensor on SPOT satellite. The time range of the data set is from May 1998 to 2013. In order to remove the noise in NDVI data, the maximum synthesis is carried out. A NDVI image is synthesized every 10 days. The data set is cut out from the global data set, so as to carry out the research and analysis of the source areas of the three rivers separately. The data format of this data set is geotiff, spatial resolution is 1 km, temporal resolution is 10 days, time range: May 1998 to December 2013.

2020-06-03

SeaWiFS NDVI dataset for Sanjiangyuan (1997-2007)

The data set is NDVI data of long time series acquired by SeaWiFS. The time range of the data set is from September 1997 to 2007. In order to remove the noise in NDVI data, the maximum synthesis is carried out. A NDVI image is synthesized every 15 days. The data set is cut out from the global data set, so as to carry out the research and analysis of the source areas of the three rivers separately. The data format of this data set is geotiff, spatial resolution is 4 km, temporal resolution is 15 days, time range: 256 days in 1997 to 365 days in 2007.

2020-06-02

HiWATER:Landsat ETM+ dataset (2012)

This dataset includes five scenes, covering the artificial oasis eco-hydrology experimental area of the Heihe River Basin, which were acquired on (yy-mm-dd) 2012-04-05, 2012-04-21, 2012-05-07, 2012-06-24, 2012-07-10. The data were all acquired around 11:50 (BJT) with data product of Level 2. Landsat ETM+ dataset was downloaded from http://glovis.usgs.gov/.

2020-05-28

Tibetan Plateau glacier data - TPG2017 (v1.0)

Based on the multispectral remote sensing data of 210 Landsat 8 oli satellites, corrected and inlaid as false color composite image (RGB: 654), the method of artificial visual interpretation is adopted, and the result of band ratio method is referred, combined with SRTM DEM v4.1 data and Google data The images of earth and hj1a / 1b satellites in different seasons of the same year, excluding the influence of mountain shadow and seasonal snow, referring to the first and second glacial cataloguing data in China, excluding the steep cliffs and exposed bedrock in non glacial areas, comprehensively extracting the thematic vector data of net glaciers, excluding the surface moraine coverage area with unclear glacier end position, and the accuracy of glacial boundary digitization is half Pixel (15m). Through comparative analysis, it can be seen that the mountain glacier data extracted based on multi data sources, reference to multi method results and integration of expert experience and knowledge is more accurate.

2020-05-12

Glacier velocity of the Central Karakoram (Version 1.0) (1999-2003)

Under the background of global warming, mountain glaciers worldwide are facing strong ablation and retreat, but from existing field observations, it is found that most of the glaciers in the Karakorum region remain stable or are advancing, which is called the "Karakorum anomaly". Glacier surface velocity is an important parameter for studying glacier dynamics and mass balance. Studying the temporal and spatial variation characteristics of glacier velocity in central Karakorum is significant for understanding the dynamic characteristics of the glacier in this region and its response to climate change. Four pairs of Landsat 7 ETM+ images acquired in 1999 to 2003 (images acquired on 1999.7.16, 2000.6.16, 2001.7.21, 2002.8.9, 2002.4.19, 2003.3.21) were selected; using the panchromatic band with a resolution of 15 m, each pair of images was accurately registered, and then cross-correlation calculations were then performed on each image pair after registration to obtain the surface velocity of the glacier in the central Karakorum region from 1999 to 2003. Due to the lack of velocity observation data in the study area, the accuracy of the ice flow results is estimated using the offset value of the stable region, and the surface velocity error of the glacier is approximately ±7 m/year. The glacier velocity data dates are from 1999 to 2003, with a temporal resolution of one year. They cover the central Karakorum region, with a spatial resolution of 30 m. The data are stored as a GeoTIFF file every year. For details regarding the data, please refer to the data description.

2020-04-29

Global GIMMS NDVI3g v1 dataset (1981-2015)

The NDVI data set is the latest release of the long sequence (1981-2015) normalized difference vegetation index product of NOAA Global Inventory Monitoring and Modeling System (GIMMS), version number 3g.v1. The temporal resolution of the product is twice a month, while the spatial resolution is 1/12 of a degree. The temporal coverage is from July 1981 to December 2015. This product is a shared data product and can be downloaded directly from ecocast.arc.nasa.gov. For details, please refer to https://nex.nasa.gov/nex/projects/1349/.

2020-04-29