Braden’s Status Report for 4/18

Accomplished

This week, I focused on verifying our project is capable of functioning with raw, field-collected inputs instead of the sanitized test vectors used to individually verify each module. I also helped implement the data communication between the FPGA and Raspberry Pi by writing a SPI protocol handler in SystemVerilog.

Progress/Schedule

Our project is currently on schedule, but the punctuality of our completion depends on the number of errors that arise during debugging.

Deliverables/Next Steps

• Collecting new test data.
• Verify all other RTL modules

New Tools/New Knowledge

Through this project, I learned a lot more about RF and analog systems. In particular, qualitative measures of success like Signal-to-Noise Ratio and methods of converting and processing analog signals in the digital realm. Understanding how this is accomplished in both hardware and software realms has opened new avenues.

Braden’s Status Report for 4/4

Accomplished

This week, I focused on correcting various errors with our Reed-Solomon error correction module. This involved stripping it down to a “dummy” module that simply passed forward uncorrected data and comparing the attempted corrections against this dummy.

Progress/Schedule

I believe that we are reasonably on schedule, as all the individual components of our project have been completed, but require testing and assembly to form a cohesive workflow.

Deliverables/Next Steps

• Fix FEC to a functional state.
• Verify all other RTL modules.

Braden’s Status Report for 3/28

Accomplished

This week, I primarily focused on developing a software solution to our demodulation problem. I worked with GNU Radio to implement a Costas Loop, Gardner Symbol Synchronizer, Root Raised Cosine Filter, Linearizer, etc. This processes our signal and reduces it to the bare binary data necessary for our protocol handler. I also worked on cleaning up the forward error correction to better interface with the other components.

Progress/Schedule

We are slightly behind schedule due to complications with FPGA modulation; however, we have a plan such that we can still decrypt satellite communications. We are focusing on validating our protocol handler such that the received signal is convertible into an image file.

Deliverables/Next Steps

• Determining feasibility/methodology to demodulate GOES signal within FPGA
• Connecting protocol handler to display module
• System-wide testing and verification

Braden’s Status Report for 3/21

Accomplished

This week, I focused on implementing BPSK modulation. I identified two modules necessary for demodulating the signal: a Costas loop and the Gardner algorithm. The Costas loop is necessary for recovering the baseband waveform; it accomplishes this by locking on to the phase and removing the carrier wave from the modulated signal. The Gardner algorithm performs symbol synchronization by detecting and adjusting for symbol timing errors.

Progress/Schedule

Based on the rapidly approaching interim demo, our team has elected to temporarily render the demodulation via Radio GNU in a Raspberry Pi. This will allow us to showcase more of our design pipeline, as the signal must be processed into a binary stream for the protocol handler we designed.

Deliverables/Next Steps

For the purpose of a more complete interim demo, we plan to work with GNU Radio to handle software demodulation of the BPSK signal. Then, we just need to properly connect the different modules of our processing pipeline.

Braden’s Status Report for 3/14

Accomplished

This week, I made progress on the forward error correction component of processing the GOES binary protocol. The packets are loaded with Reed-Solomon error correction codes, which when properly handled, enable a degree of calculated signal recovery.

Progress/Schedule

Our team is reasonably on track, with us winding down work on the protocol handler. Once the protocol handler is complete, work only remains on signal demodulation and image display.

Deliverables/Next Steps

Next week, our team hopes to focus on demodulating the BPSK signal, such that it is converted into a binary stream fed into the protocol handler.

Braden’s Status Report for 3/07

Accomplished

This week, I primarily worked on developing a RadioGNU workflow for capturing and visualizing data from the GOES system. Now that our parts have arrived, we can attempt to interface with the weather satellites. I also made progress on the SystemVerilog for the Reed-Solomon forward error correction technique.

Progress/Schedule

We are behind schedule due to unexpected part malfunctions while field testing. Our SDR was unable to power on; we plan to swap it with a prepared replacement for future excursions. If our equipment functions as intended next week, we should properly receive data.

Deliverables/Next Steps

Looking into next week, I expect to capture field testing data from our antenna. This will allow us to test our RTL with the actual protocol. I will also continue working on the forward error correction algorithm.

Additional Questions

With consideration of environmental factors, our project proposes a low-infrastructure, low-power, reusable, and portable method for receiving weather data. Since our device only receives RF broadcasts (no transmission is necessary), any electromagnetic interference irradiated is kept to a bare minimum. It also provides advance notice to users of any adverse environmental factors, while keeping its own effect on the environment to a minimum.

Braden’s Status Report for 2/21

Accomplished

This week, I contributed to the design presentation by adding quantitative benchmarks for our project goals. We also received our parts near the end of the week, so I met with the group to assemble our antenna and test it in the field. I was able to receive a signal on the antenna and view it via a simple RadioGNU program.

Progress/Schedule

I am generally on schedule now that the parts have arrived. The main focus is ascertaining a satellite signal and collecting data for demodulation.

Deliverables/Next Steps

Next week, I will:

• Complete the RadioGNU workflow for receiving antenna data
• Capturing real world data to use as test inputs.

Braden’s Status Report for 2/14

Accomplished

This week, I investigated the layered protocols necessary to interpret the GOES signal. The signal arrives as a binary protocol modulated with BPSK for analog transmission. Deciphering the binary protocol reveals the image data our device wants to display. Hence, I worked on calculating the forward error correction code.

Progress/Schedule

I am mostly consigned to researching methods for accomplishing our project goals until our parts arrive. They are expected to arrive next week.

Deliverables/Next Steps

Next week, I will:

• Receive the parts for our project.
• Capture a GOES signal in the field.

Additional Question(s)

In regards to the social impacts of our project, we envision our device as useful to isolated or disconnected communities which cannot rely on traditional broadband resources. Hence, being able to access timely, detailed weather reports provides useful information to potentially disadvantaged communities. Notably, our device provides both benign and crucial weather updates, meaning that while it provides warning for inclement conditions, it also provides practical notifications like incoming rain or temperature fluctuations for users to plan their lives around.

Braden’s Status Report for 2/07

Accomplished

This week I researched the GOES satellite protocols. The primary transmission methods of interest to us were the GOES rebroadcast (GRB) and High Rate Information Transmission (HRIT), where GRB is modulated with QPSK and HRIT is modulated with BPSK. Ultimately, it was decided to focus on receiving HRIT/LRIT signals, since the GRB signal requires a significantly larger antenna dish, which would affect the usability and portability of our device. Following these developments, I looked into specific equipment that would enable our device to receive and demodulate these protocols. Specifically, I found a 1.7GHz GOES antenna and a low-noise amplifier to act as our RF front end.

Progress/Schedule

I am currently on track. The primary accomplishment slated for this week was determining and obtaining the necessary parts for our project. It was of particular importance to secure an SDR and antenna so we could begin capturing satellite data.

Deliverables/Next Steps

Next week, I plan to interface with the SDR to identify how RF IQ data is delivered. This should provide insight into how our demodulation program can be structured. Furthermore, when our antenna is delivered, I plan to capture data from the GOES satellite for testing.