What This Series Already Taught Us
Two earlier companions in this series already touched antenna setup directly. This chapter states plainly what they covered, so the rest of this companion can build on that foundation instead of repeating it.
Rod height, measurement method settings, and pole tilt were all covered in earlier companions as practical field habits. This companion goes underneath those habits, to the actual physical and electrical reasons they matter.
What Was Already Said About Height and Method
An earlier companion in this series established that a rod's printed graduation is not automatically the true antenna height, and that the complete physical assembly, pole, adapter, mount, and any spacer, has to be measured directly rather than assumed. A different companion established that the measurement method setting in field software, vertical, slant to a notch, or true vertical, applies its own internal conversion, and that a mismatch between the actual measurement technique and the selected setting silently mismeasures the antenna even when the entered number is accurate.
Both of those earlier lessons were about getting a number into the software correctly. Neither one explained what that number is actually being converted toward, which is exactly where this companion begins.
What Was Already Said About Tilt
A separate chapter in this series covered pole tilt directly: a rover pole leaning even slightly displaces the antenna horizontally, by an amount that grows with both pole length and tilt angle, and tilt-compensated poles manage that problem within a calibrated range rather than eliminating the need to care about it. That explanation stopped at the geometry of the pole itself. It did not explain what tilt compensation hardware is actually doing internally, which this companion returns to directly in a later chapter.
This companion is not a second, deeper explanation of rod height, measurement method, or pole tilt from scratch. It assumes those field habits are already understood, and focuses entirely on the antenna itself, the part of the setup none of that earlier material actually opened up.
What Neither Companion Explained
Nothing covered so far in this series has explained what a manufacturer's antenna reference point actually is, why the electrical center of an antenna sits somewhere else entirely, or how field software and post-processing software each actually use that relationship, which turns out to differ more than it might seem. That is the entire subject of this companion, starting from the one physical point a crew can actually touch.
A crew has always been careful about rod height, measurement method, and pole tilt, exactly as earlier companions in this series describe. Does that guarantee the antenna itself is being handled correctly? Not entirely. Those habits address getting a height measurement into the software correctly. They say nothing about the antenna's own reference point and offset, which is a separate, additional source of error this companion covers directly.
Rod height, measurement method, and pole tilt were all covered earlier in this series as practical field habits, and this companion assumes that foundation rather than rebuilding it. What follows is the material none of those chapters opened: the antenna's own reference point and electrical center, and how RTK field software and post-processing software each actually make use of that relationship.
Start with the one point on an antenna a crew can actually touch and measure to, and the specific, defined meaning behind it.