Is There Any Way to Get NIR Spectral Data from Before Sentinel Satellite Imagery?

Question

I'm trying to create a raster layer of annual average MSAVI2 values (https://pro.arcgis.com/en/pro-app/latest/arcpy/spatial-analyst/msavi.htm, a modified form of NDVI) for each year from 2000 to 2021. To do this, I need both the Near InfraRed (NIR) and red bands found in the Sentinel-2 MSI: MultiSpectral Instrument, Level-1C image collection in order to calculate MSAVI2. The issue is that the sentinel 2 data only goes back to 2015, so I am unable to calculate MSAVI2 for any years prior.

Here's my current setup for calculating a MSAVI2 raster layer for a given year (2018 in this case)

```
var s2 = ee.ImageCollection("COPERNICUS/S2");

//compute composite for all images for a given year
var composite = s2
  .filterDate('2018-01-01','2018-12-31')
  .mosaic()
  .divide(10000)

Map.addLayer(composite, {bands: ['B8', 'B8', 'B4'], min: 0, max: 0.4}, 'composite')

// compute MSAVI2 using expression
var msavi2 = composite.expression(
  '(2 * NIR + 1 - sqrt(pow((2 * NIR + 1), 2) - 8 * (NIR - RED)) ) / 2', 
  {
    'NIR': composite.select('B8'), 
    'RED': composite.select('B4')
  }
);
//add the MSAVI2 layer
Map.addLayer(msavi2, {min: -0.1, max: 0.5}, 'msavi2')
```

Is anyone aware of any raster layers in GEE that would have the necessary bands and go back to 2000?

Is There Any Way to Get NIR Spectral Data from Before Sentinel Satellite Imagery?

0 Answers0