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Processing High-Resolution Optical Imagery

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11-30-2014 11:21 PM
larryzhang
Frequent Contributor
0 2 998

In operation, people very commonly think that today powerful computers would help imagery specialists effectively to perform automation of color-balancing and spatial rectification for imagery processing (i.e., without intensively human involvements).

Obviously, it is wrong impression,  Including the use of GPUs-based supercomputing workstation, or multi-core /processor CPU-based server machines (over load-balancing cluster or Cloud infrastructure)...

In fact, imagery specialists are still facing challenges ‘effectively and accurately’ to process high-resolution (0.31-2.5 m) optical imagery for larger coverage (from hundreds of thousands to millions KM2), which is critical to support operations and many applications (# 1 below).

From frontline experiences, in addition to technical challenges, there is major barrier to tell people the limitations of current computer solutions with any latest imagery-processing-related algorithms, no matter how powerful those solution packagess are…


Certainly, massively 'manual' adjustment in color and spatial accuracy are highly required, to meet high-standard operation requirements like features' enhancement in mosaic, in addition to color-balanced requirement (#2 & 3 below).

Due to spectral variations, there are still some issues like seamlines in some areas (# 4 below).

mosaic.png

1. High resolution (0.5-m) satellite imagery mosaic covering the area of over-2-million KM2,  which is well-balanced in color and spatially rectified

well-color-balanced.png
2. Overall, visible and near-infra remote sensing technology can be perfectly applied to the areas with limited variations to the landscape, which allows for nice color balancing in the entire region
high-level and clear features in color-balanced mosaic.PNG
3. High-level and clear features for feature extraction, mapping, and cartography in well-balanced color mosaic
some-seamlines.png
4. However, some seamlines are still visible among scenes in some areas (around 3-5% of scenes) , due to 'huge' spectral differences, including atmospheric conditions
2 Comments
by Anonymous User
Not applicable

Great overview, Larry.  Can you share more information about the dataset you are leveraging in your iillstrations above?  Thanks for the info if you can share.

larryzhang
Frequent Contributor

Pierre,

Raster datasets in the final mosaic come from multiple sensors (which are acquired within one single year), predominantly (around 85%) from (0.5-m-resolution) GeoEye, Pleiades, and WorldView, in combination with 1.5-m-resolution SPOT and 0.3-m airphotos mainly filling the gaps among above raster datasets.

As I know, raster datasets covering this region by another service provider uses only WorldView-2/3, but acquired over many years...

About the Author
A veteran GEO engineer in petroleum and mining industries, specialized on digital twin & mapping (business and urban assets by drone mapping and mobile mapping), geomatics (geospatial intelligence, GIS), and geology (geological mapping, quantitative exploration). Vigorously devoted to GEO analytics and GEO Intelligence, especially data integration and integrity for data center over HPC and cloud infrastructures....