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Help a newbie get some digital numbers!

Question asked by T.HoseasonUEA on Nov 16, 2017

Hello, I was hoping that someone could help guide a poor newbie trying to navigate the big bad world of ArcGIS Pro. I am currently working on an undergrad project looking at turbidity in rivers using satellite imagery (provided by Planet Labs RapidEye systems) but I seem to have reached a stumbling point. So far, I have managed to import the images into Pro and have created mosaics using the ‘Mosaic to New Raster’ function, which has allowed for the relevant bands (I am mainly interested in the red and near-infrared bands in this instance) to be readily accessible.


However, I am now trying to figure out where to go from here. Essentially, I need to produce radiance values from digital numbers (as set out in the Planet Labs Imagery Product Specification), but how this is achieved is still a bit of a mystery. Initially, I thought the best first step would be to crop out a small section of the river around one of the USGS turbidity stations, which I will be using to compare the satellite data against, and simply do some small-scale testing. Presumably, this would require some new polygon shapefiles to be produced, but even this has proved trickier than it should.


So essentially, I need some suggestions of possible methods of obtaining these DN values so that I can produce my radiance values. I am almost entirely self-taught, so many of the finer details of how to use the program are still a little hazy. Taking my first tentative steps into this new world seems extremely daunting at this point, so any help you can provide would be greatly appreciated! Please let me know if you require any further information or if anything needs clarifying or expanding upon. I can provide some sample images if that helps.


Thanks in advance!