How to drive a 1MHz Ultrasound-TD1000KA
To drive it as the datasheet specifies you need a precise 1MHZ 100 to 200 volt pulse generator with a 2% duty cycle, or a pulse width of 20ns. Too wide a pulse or too high a voltage may damage the sensor.

Reflected return time = distance to sediment density. Reflected signal strength indicates sediment density. If the sensor is in a controlled xy motion then both time and strength values will change, so you can form a map-if that is your long-term goal.

To process this data you would need LabVIEW and a fast digitizer board (10msps)to extract and display the results (you or a third party writes the code) so the final image and stats have useful meaning.