[m2fkxy]

A little nitpick about:

  The number of looks correlates with a higher resolution.

Yes and no. When you task an image, you usually (as is the case with Umbra) specify your desired ground resolution, eg. 25, 50, 100 cm, etc. There are two dimensions in a SAR image: range and azimuth. Range resolution is determined by the SAR system bandwidth. Azimuth resolution is determined by the integration angle (the angle formed between your target and your satellite from start to end of the collection).

Let's assume you want a 50 cm image. Your range resolution will be equal to that and, in a 1-look image, your native azimuth resolution will also be 50 cm. What happens when you request a multi-looked image, is that the satellite will collect data over your target for a longer amount of time (and thus over a greater angle diversity). Range resolution will not change; however, in the natural ("native") image, you get asymmetrical pixels: taking the same target resolution of 50 cm, a 2-looks image will have a 25 cm azimuth resolution. For 3-looks, ~16 cm. And so on.

What then happens during the processing of derived products (eg. GEC) is that the pixels are squared: to do that, you have to average out the pixels in the azimuth dimension. This greatly improves what is called the radiometric resolution (ie. how much information a pixel contains), by cancelling out the speckle and averaging the noise. But for all intents and purposes, on a multi-looked image (which is what the GEC products that you use are), spatial resolution remains the same, square pixel.

[SAR nerds here: I am not mentioning the slant-range-to-ground-range process, and I am also ignoring the resolution vs. sampling distinction for simplicity]

[OJFord]

I know nothing about any of this, but:

> Azimuth resolution is determined by the integration angle (the angle formed between your target and your satellite from start to end of the collection).

For any non-zero value (geostationary), wouldn't it be a quadrilateral rather than an (single) angle? Or is it, measured from Earth, the change in angle from 'straight up' to satellite? But then how would the satellite calculate/observe that?

Or is that what you're saying the resolution derived from that is, the ground distance that that same angle moves over in the time taken?