Ultrasonic Transducer AFE / Pulser-Receiver Electronics Development -- 2

Objective: The goal is to design and develop functional prototype AFE(Analog Front End)/pulser-receiver system that can directly interface with any raw underwater transducer (200KHz to 1MHz) and deliver full echo-profile data to a Raspberry Pi.

Description: I am looking for an experienced analog electronics / ultrasonic / sonar engineer to design and develop (physical device) a custom electronics board (AFE) to interface with a raw underwater ultrasonic transducer.
The board will interface directly with a raw piezoelectric ultrasonic transducer and provide the complete transmit and receive signal chain. The transducer we are using is:
https://ultrans.en.made-in-china.com/product/yxYUzZhJhOpW/China-500kHz-Ultrasonic-Underwater-Acoustic-Transducer-Ranging-Transducer-Fishfinder-Transducers-Chirp-Transducers-Transducers-FYW-500-20B-for-Positioning.html

The basic architecture is:
Piezoelectric Ultrasonic Transducer ↔ TX/RX Front End ↔ ADC ↔ Raspberry Pi / Processor
Required Electronics

The AFE should include:

1. Transducer interface
2. Transmit / Pulser
3. Transmit/Receive switching
4. Receive Analog Front End
5. ADC / Data Acquisition
6. Digital interface
7. Trigger / timing

Desired Output: For each transmitted ping, I want to obtain data similar to:
Amplitude / signal strength vs. time or range (Full Echo Profile output).

I need the complete Altium source files in addition to the Gerber files. Please provide the schematic source, PCB source/layout, Gerbers, BOM, pick-and-place files if applicable, and all design documentation. The PCB should be designed specifically for a ~500 kHz underwater piezoelectric transducer and must include the TX pulser, T/R protection/switching, low-noise receive AFE, filtering, ADC, timing/triggering, and interface to a Raspberry Pi for full echo-profile acquisition. I also need an assembled and tested prototype, not just manufacturing files.

The freelancer will provide the following items:

Gerber ZIP
NC drill files
Final BOM with manufacturer part numbers
Pick-and-place/centroid file
Assembly drawing
Schematic PDF
PCB layout PDF
PCB source files (KiCad/Altium/etc.)
3D STEP model
Fabrication/assembly notes
DFM/DRC/ERC reports
Firmware/programming requirements