Sydney Storm Fly Over, page-44

Satellite versus aerial images


Pro satellite images:

The satellite platform is operational 365 days of the year
Frequent re-visit times (e.g. every 4 days or even more)
The satellite can easily access remote or restricted areas
There are no Air Traffic Control restrictions
Large area footprints decrease the need for block adjustment and creation of image mosaics
No aircraft, cameras or otherwise expensive equipments are required (by the end user)

Contra satellite images:

The image acquisition geometry is not very flexible
The imaging time is fixed. It cannot be optimized with respect to weather conditions and cloud coverage
The image resolution is fixed for a particular sensor and low compared to most aerial imagery. Aerial images can be collected with the same resolution (in high altitude mode), if necessary
The radiometric resolution is often too low (problems in shadows and saturation areas)
The image quality is often impaired by different factors and artifacts
The typical off-nadir viewing angle of up to 25° is problematic in image matching
The reliability of capture and delivery of imagery can be poor at times
Strong possibilities of cloud cover and thus occlusions
The cost of the imagery may be too high (when compared to aerials). Especially multi-image (>2 images covering the objects) concepts are financially hard to realize.


http://www.geoinformatics.com/blog/...s-aerial-images-not-always-a-matter-of-choice