Data Fusion

Data fusion techniques combine data from multiple sensors, and related information from associated databases, to achieve improved ac-curacies and more specific inferences than could be achieved by using a single sensor alone.

Single sensor – spatial (QuickbirdMultispectral + Pan)
Multi sensor – spatial (Landsat 30m + SPOT 10m)

Most of these sensors operate in two modes: multispectral mode and the panchromatic             mode.
Usually the multispectral mode has a better spectral resolution than the panchromatic                   mode.
Most of the satellite sensors are such that the panchromatic mode has a better spatial                 resolution than the multispectral mode.
To combine the advantages of spatial and spectral resolutions of two different sensors,                image fusion techniques are applied  


This improves the interpretability of the data by having high resolution information which is also in color. Resolution Merge offers three techniques: Multiplicative, Principal Components, Brovey Transform and IHS under sensor merge. 

• Multiplicative is based on simple arithmetic integration of the two raster sets. 
• The Principal Components merge operates on PC-1 rather than the input raster image. 
• In the BroveyTransform option, all bands are used according to the following formula: 
• [DNB1 / DNB1 + DNB2 + DNBn] x [DNhigh res. image] = DNB1_new
• [DNB2 / DNB1 + DNB2 + DNBn] x [DNhigh res. image] = DNB2_new
• etc. 
• whereB = band 


Step 1,

Open ERDAS Imagine --- Raster --- Pan Sharpen --- Resolution Merge

Step 2,

For the High Resolution Input file select Panchromatic image.

Step 3,

For the Multispectural Input file select Multispectural image.

Step 4,

You can give output file name and in "Method" select 1st option "Principal Components".

Step 5,

Then press ok, progress window will be appear, wait few seconds to complete the process.

Step 5,

Add your image to the ERDAS

Step 6,

Then select another 2D view for next image,

Step 7,

to get Multiplicative image fallow the same steps and select "Multiplicative" option.

Step 8,

Wait for process to be complete...

Step 9,

Then add your image, the to get a Brovey Transform image followe the same steps and select "Brovey Transform"

Step 10,

Add your image,

Step 11,

Then go to Raster -- Utilities -- Sensor Merge -- 

Step 12,

Follow the same steps and select "IHS"

Step 13,

Add IHS image also to the ERDAS