Wow, that's a lot more math than I was doing.

Help me translate that to English for a guy who 20 years ago failed linear algebra on the first attempt, and barely scraped by on the second...

Roughly speaking, it sounds like coordinates are weighted by HRMS and VRMS with a couple coordinate transformations/re-projections in the process.

Here are some more particulars on the shots.

Name 8104 8104A

Horiz. Residual 0.034ft 0.018ft

Time 10:39:40 10:43:17

Epochs 592 594

GPS 6 6

GLONASS 7 7

HRMS 0.008ft 0.007ft

VRMS 0.014ft 0.015ft

HDOP 0.760 0.758

VDOP 1.404 1.351

TDOP 0.943 0.907

Confidence 14.00 13.00

Consistency 874.50 880.00

Duration 121.8s 121.8s

It looks to me like the cluster average has weighted one shot approximately twice as much as the other, but I don't see much difference between shots. The spread between shots is small, so maybe it's just from accumulated rounding errors?