rabarth Posted November 21, 2014 Report Share Posted November 21, 2014 HI guys. I am new to the forum, and also a bit to the world of remote sensing. I am looking at the moment for NDVI data, I need it for a porject about desertification. I found the MODIS NDVI data, but just since the year 2000. There is data available from before (since around 1982) from the NOAA AVHRR, but I cannot find it. Somebody knows about it, where I can get it from? and is this data also already processed (like the MODIS data), so that I just have to download the NDVI values? or can I just obtain the pictures with the different bands? Thanks for an answer! Raphael 1 Quote Link to comment Share on other sites More sharing options...
anaximander Posted November 23, 2014 Report Share Posted November 23, 2014 Hi Raphael, You can find the 'GIMMS AVHRR Global NDVI 1/12-degree' data at the link below http://ecocast.arc.nasa.gov/data/pub/gimms/3g/ The data range is from 1982 to 2012 I believe. The data is in binary format but I have found a way to read it using R. However, I think you can read it pretty easily with ENVI as well once you get the header figured out. Let me know if you need some help with this as I've looked into this data a little bit a while back All the best! Regards, Jason Quote Link to comment Share on other sites More sharing options...
rabarth Posted November 24, 2014 Author Report Share Posted November 24, 2014 Thanks a lot first! Tell me, the data in the files, are these monthly average values? And the pixels are around 8km x 8km big? I haven't worked with ENVI before. I can also load it in ArcGIS and then just read out the values I need for my specific place? Or do I need to pre-process the data? Raphael Quote Link to comment Share on other sites More sharing options...
anaximander Posted November 25, 2014 Report Share Posted November 25, 2014 Thanks a lot first! Tell me, the data in the files, are these monthly average values? And the pixels are around 8km x 8km big? I haven't worked with ENVI before. I can also load it in ArcGIS and then just read out the values I need for my specific place? Or do I need to pre-process the data? Raphael Hi Raphael, The data is has a spatial resolution of 9 km and are 15 days maximum composites. I haven't used ArcGIS to work with this data so I can't quite comment much about it but the link below should give you a good start - http://gis.stackexchange.com/questions/104500/how-to-create-several-header-files-to-open-avhrr-ndvi3g-gimms-files There's also a much more detailed explanation about the dataset in the pdf that can be found at the following link http://www.mdpi.com/2072-4292/6/8/6929 I hope this helps! Jason Quote Link to comment Share on other sites More sharing options...
rabarth Posted December 3, 2014 Author Report Share Posted December 3, 2014 (edited) okay. I'm gonna read it But probably the Data won't be good enough for my project, cause my project location is about 0.4km^2 big... Thanks a lot Jason!! Edited December 3, 2014 by rabarth Quote Link to comment Share on other sites More sharing options...
maggis Posted March 11, 2019 Report Share Posted March 11, 2019 You may find NDVI data that predates year 2000 via satellite imagery service called LandViewer. This tool has a vast database of satellite imagery that is publicly available and is updated on a regular basis. You may set any Index you need to analyze the area of your needs or create any Index of your own. Besides that there are already ready-made tools for obtaining multispectral indices, flexible processing of data on AOI, elementary clustering, using a raster calculator, visualization of scenes in 3D using digital elevation models, changes in territories based on multi-temporal multispectral analysis, as well as creating ready-made animations of changes in terrain and so much more. Here’s a brief guide to free satellite data that can be found on : Landsat 4 - archive 1982-1993 Landsat 5 - archive 1984-2013 Landsat 7 - archive since 1999 MODIS - archive since 2012 Landsat 8 - archive since 2013 Sentinel-1 - archive since 2014 Sentinel-2 - archive since 2015 An example of such imagery with an applied NDVI index can be seen below. https://eos.com/landviewer/?lat=33.04234&lng=-96.62132&z=11&id=LV-TFQw-NV9M-MVRQ-XzAy-NzAz-N18x-OTk5-MTIz-MV8y-MDE2-MDkx-OV8w-MV9U-MQ%3D%3D&b=NIR,Red&expression=(B4-B3)%2F(B4%2BB3)&anti Quote Link to comment Share on other sites More sharing options...
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