On-Orbit Processing involves the compression of captured images and preparing them for transmission to Earth.

How did we get here?

We can enter Processing Mode from either Imaging Mode or Idle Mode. Processing requires a massive amount of power so battery level is the main SSV that needs to be satisfied.

What do we do here?

4.1 Image Storage and Compression

FMEA Considerations

• Not enough storage in PAY_MEM
• Compression Algorithm fails to be reconstructed
• Image is/gets corrupted
• Data path breaks:
  • Between camera and frame buffer
  • Frame buffer and PAY_MEM
  • PAY_MEM to PAY_MCU
• PAY_MCU draws too much power/heats up

4.1.1 Image Data to Pay_MEM

Uncompressed image data is continuously streamed to the an external frame buffer. Once the entire image is taken, the image data is then transferred from the frame buffer to the on-board SD card; this on-board SD card is what we call Pay_MEM. This all happens in Imaging Mode and the uncompressed data sits here until we enter processing mode. once we enter processing, the data is sent to the PAY_MCU for compression.

Does Image data get streamed directly to pay MCU after imaging? If not, where is it kept until then? Can we hold more than 1 image in the memory/frame buffer at a time (if so, how many)? What protocol is used for streaming data to PAY_MEM and to send data between PAY_MEM and PAY_MCU?

4.1.1 Image Data to PAY_MCU for Compression

Once the data is moved to PAY_MCU, it is compressed using our compression algorithm.

Compression Algorithm

This algorithm is based on the CCSSDS123 standard. Key features of the algorithm include:

• Input of a 3D array of integer values (i.e. the captured image)