What is the HOB correction when two airbursts and two graze bursts are observed during precision registration?

In the context of precision registration, the observed impact of airbursts and graze bursts provides critical information for adjusting artillery fire. When two airbursts and two graze bursts occur, it indicates that the rounds are impacting higher than intended.

In such a scenario, it is necessary to make a correction to bring the effects of fire closer to the target. Given the nature of the bursts observed, a correction is typically determined based on the patterns and types of impacts. The correction of "Up 10" signifies an adjustment of 10 mils in elevation to counteract the higher-than-expected impacts.

This adjustment ensures that subsequent rounds will land closer to the desired point of impact, which is crucial for achieving effective fire support during operations. The other corrections do not align with the observed impacts and would not adequately adjust for the airburst and graze burst phenomenon identified during the registration process.