When using the Torch and enabling “Report Tip Altitude,” does this mean the output position already includes the antenna height plus the phase center offset? I noticed that in SW Maps, it’s common to set the antenna height to 0 to avoid double-counting it.
We’re planning to measure a point located 5 meters underwater using the Torch mounted on a pole. From what I understand, we need to input the pole length (approximately 6 meters) plus the 116 mm offset from the antenna phase center, for a total height of 6.116 meters. Is this the correct value to set internally when “Report Tip Altitude” is enabled?
I remember the first time we used the Torch with a 3-meter pole, we never saw it enter tilt-compensation mode. I’m now assuming this might have been due to “Report Altitude” being disabled by default from the factory, or possibly because we didn’t configure the antenna height correctly.
This topic has been surprisingly informative—I realized I barely understood how this works. I’d appreciate any clarification or guidance you can provide.
@Avantasian, In General - it would be more common to not use the “Report Tip Altitude” in the Torch, instead enter the specific Rod Height in SW Maps for the shot(s).
If you need to change the Rod Height in the field, it’s easier to adjust the value in the Data Collector APP, verses reconfiguring the Torch’s Firmware, IMHO.
Keeping the 6m Rod plumb will be a bit of a challenge, so use a Rod bubble if you can.
Also, calm water will reflect the GNSS signals (multipath) much more than land will, so a ground plane under the torch would be beneficial to you if that’s not too much trouble.
Side Note: The ability to go ahead and account for the APC in the Torch FW is nice…that way we can enter the actual Rod Height in SW Maps. IE: It’s rare for a survey rod to be actually 2.000 meters when accounting for the spike/tip and how the Receiver indexes on the threads. Once you physically measure a specific rod, that difference can be included in your APC value to “calibrate” the rod. Then the pre-defined registration marks on an adjustable rod are accurate.
But we (most of the people I know) just use a fixed 2meter GNSS rod and use the actual Instrument Height + APC after careful measurement… and that doesn’t change until you wear down the replaceable spike/tip. I write that value (and receiver model) on the ROD with a Sharpie.