This dissertation describes the design, implementation and testing of the Radar Digital Unit (RDU), a subsystem for the South African Synthetic Aperture Radar II (SASARII).
The SASARII is an airborne demonstrator SAR system for a spaceborne SAR and Unmanned Aerial Vehicle (UAV) imaging radar. The demonstrator system parameters, such as bandwidth, reflect the desired spaceborne SAR parameters.
The Radar Digital Unit contains the following three modules:
- Digital Pulse Generator (DPG) that outputs a chirp every Pulse Repetition Interval (PRI) for transmission
- Sampling Unit (SU), which samples the received IF signal every PRI, forms a packet of samples and flight information and sends the packet for storage
- Timing Unit (TU), which distributes triggers to the SASARII system every PRI.
Based upon the user requirements, Parsec, a company in Pretoria, South Africa, supplied generic hardware for the RDU. SASARII firmware was developed for each module at Parsec under their guidance and support. The testing of the three modules was conducted at Parsec and at the Radar Remote Sensing Group.
Each module was tested individually. The following was concluded from the test results:
- The DPG firmware and hardware operate to specification
- The SU firmware functions correctly
- The TU firmware simulates correctly. During testing a possible hardware bug was found. Parsec, the supplier of the module, was informed about the hardware bug.
At time of writing this dissertation the problem had not been solved.