[Aust-NZ] How Does Satellite Imagery Compare with Aerial Photography? [SEC=UNCLASSIFIED]

[Bruce Bannerman]

Hi John,

> 
> On 6 April 2010 21:13, Bruce Bannerman <B.Bannerman at bom.gov.au> wrote:
> > Resolution is only part of the story.
> 
> Sure, depends on your use of the imagery.
> 
> > A major advantage that you have with typical remotely 
> sensed imagery such as satellite imagery is that the sensor 
> used often captures many spectral bands of data.
> 
> This can be a disadvantage when you are only interested in the visible
> (non-IR/non-UV) spectrum, I find Google's current sat imagery 
> gets the colours very wrong, where as aerial imagery doesn't 
> suffer this because they only deal with visible light spectrum.

There is nothing to stop you just using the bands in the visible part of the spectrum (assuming that your sensor supports this) i.e. map:

Sensor:	Display:

Red		Red
Green		Green
Blue		Blue

This will give an image approximating what people are used to with an aerial photo.

Image enhancement techniques (as are applied to aerial photography) will improve the representation.


> 
> > With aerial photography, you are typically restricted to 
> just three spectral bands (red, green and blue), though near 
> infra red is sometimes used to check vegetation health.
> 
> You are restricted to whatever sensors are flown, satellites 
> are restricted to what ever they're launched with, at least 
> with aerial imagery you can change between flights.
> 

Bruce