Tool for a moving average over a time series

Question

Dear all,

I am looking for a tool to create a pixel-based moving average from a range of MODIS EVI tiles (from 2001 to 2013).

Is there a tool in ArcGIS to create the respective raster data sets by aggregating for example 3 time steps?

Thanks for your help,

Stefanie

DanPatterson_Retired · Answer

No...It is important to learn as many languages as possible...there isn't a code Bablefish however.

StefanieSteinbach · Answer

Thanks for the code, I'll try it on my data and will give you feedback!

I guess there's no way around Python when seriously working with ArcGIS..

DanPatterson_Retired · Answer

What you want is to do is code the local statistics in a moving loop... sorry to stick to code but ultimately you want something like this

>>> import numpy as np
>>>
>>> rasters = np.array([1,2,3,4,5,6,7,8,9])
>>> moving_mean = [np.mean(rasters[i-3:i]) for i in range(3,len(rasters)+1)]
>>> moving_mean
[2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0]
>>>

but using something like this totally unchecked code (money refunded if it doesn't work)

arcpy.CheckOutExtension("Spatial")
env.workspace = "C:/somepath/to_your/data"
rasters = arcpy.ListRasters("*", "GRID")
ras_name = "amazing"
for i in range(3,len(rasters)+1):
    outras = CellStatistics([rasters[i-3],rasters[i-2],rasters[i-1]], "Mean", "NODATA")
    ras_name = env.workspace + "/" +ras_name + str(I)
    ras_name.save(ras_name)

Now maybe someone with some data, or is so inclined could check this out.

Other info http://desktop.arcgis.com/en/desktop/latest/analyze/arcpy-functions/listrasters.htm