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Catherine Nakalembe

👤 Person
334 total appearances

Appearances Over Time

Podcast Appearances

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

So I could try to map it really well.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

I could get all the information directly on the ground.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

But I'd still do a pretty bad job because the model has learned about other things that have nothing to do with our reality.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

So there's one side of it.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

One side of it is in order to get useful information from satellite data, we build models.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

You have to train the model using some existing example.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

And then the model goes through all the satellite data and tries to find that thing that you were looking for.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

And that's how we would create like a crop type map.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

Today, most models do very well for farmland in the United States.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

The fields are really big.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

They're homogeneous, so there's like one crop over a really large area.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

There's been a lot of investment in collecting data to have those examples.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

So when I build a model and train to predict what is growing in Kansas, it's easy.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

But for me to produce a map of where maize is in Kenya, a whole different story, because I don't have those examples yet.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

It's much harder to collect the data because there's no default data collection for this purpose.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

The other side of it is that the satellites that we have access to, where we have open data that allows you to scale for all of Kenya, the resolution doesn't fit the small Kenyan fields.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

And so if I use the same amount of labels but trained on the same data set for Kenya and the U.S.,

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

It wouldn't work because these fields are so much smaller and much more complex.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

So the products we have are usually not relevant at the farmer's scale.

TED Talks Daily
How satellites are supporting farmers across Africa | Catherine Nakalembe

They're relevant at a larger scale.