For a pushbroom scanner like Worldview 1 calculate the data

For a pushbroom scanner like Worldview 1, calculate the data rate implicit in the panchromatic sensor system with a 35,000-pixel linear array, assuming 11 bits/pixel. Assume a square image. Data compression by a factor of 4 reduces the required number of bits to 3 bits/channel. Onboard storage is 2.2 Tbits. Calculate the number of bits in one image (compressed). How many such images can be stored? How long will it take to transmit one such image to the ground? (800 Mbit/s X-band).

Solution

As there are 35.000 pixels and each pixel has 11 bits, an image not compressed will have 385,000 bits.

Using the data compression of 4, one image compress has 96,250 bits.

As the storage is 2.2 Tbits, it is possible to store 22.857 millons of images.

For transmiting an image of 96,250 bits, as there are 3 bits/channel and the transmission , for each second (considering 1 channel) , 2400 Mbits will be transmited. For transmitting 96,250 bits, it will take 40.1 microseconds to transmit one image.