operational amplifier - What is the use of an op-amp whose output and inverting input are connected to ground?

I am in first year of Engineering school and I was given an assignment containing this circuit, which drives pressure sensors in a pitot tube :

I am struggling to understand the whole circuit, and more precisely the first op-amp, which output (pin 1) and e- (inverting) input (pin 2) are connected to ground.

What is its use? How can such an op-amp have an influence on the overall circuit, if its output is not used?

Answer

The first OP-amp is actually creating the circuit ground. The 7810 creates a stable 10 volt, which is then divided by the voltage divider R2 and R3, filtered by C3 to make a stable 5 volt level relative to the most negative level.

The OP-amp then buffers this, and the rest of the circuit uses its output as the reference ground. Remember that ground in a circuit like this is just a convenience, a node that is used when referring to other voltages.