My First OPUS Submission

26o

are you using TBC?

Posted by: @rankin_file

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are you using TBC?

No. I have another question. I'm trying to figure out the antennae type. I used a Carlson BRx7, which is using a Hemisphere S631 antennae.

Submission successful. What is the NONE after HEMS631? Please see the attached file. The email address field was erased on purpose.

Yet, another question.

<Row>
<Name>AntDeltaHeight</Name>
<Value>1.4520</Value>
</Row>

My measure up from the ground to the mark on the antennae was 4.95'. The difference between that height and the antennae delta height is significantly larger that the anticipated phase center offset.

NONE indicates that there no weather dome added to the antenna, i.e. it's the antenna as it came from the factory.

Not sure what's going on with the heights, but if you entered the measurement from the ground point to the ARP (bottom of the antenna mount, judging from the diagram), you should be okay.

Posted by: @field-dog

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What is the NONE after HEMS631?

I dont really know the significance of the [NONE], but that is simply the name the NGS has given to that model antenna.

Please clarify your measure up. Was it to the bottom of ant mount, or to some other index point on the receiver?

@rankin_file 

I think I submitted an incorrect measurement. Jim Frame did mention the ARP, but I guess I didn't fully comprehend it. I actually thought about it when I was eating lunch thinking I messed up, then you posted the question. My answer is I measured to an index point on the receiver as shown in the attached picture. Where is the bottom of the antennae mount? Is it where the pole threads into the receiver? The word mount is confusing me.

That is correct- it is where a regular 5/8x11 would screw into it. It appears you measured to the slant height index mark. 
So draw yourself a picture of a right triangle - short side is 78.5mm/2 and the hypotenuse is the metric equivalent of 4.95’- solve for the long side using Pythagorean - subtract 54.7 mm. That’s your measure up to the ARP. 

 I keep an excel spreadsheet sheet to do just this- enter the slant height in feet and it does the rest.  I have a formula for  R8’s, R10’s and for the 5700 back when they were operational. Email me if you want a copy

This picture, which references the position of the ARP for that antenna, come from the NGS Antenna Calibrations page.  

Thanks @norman-oklahoma for posting the actual NGS calibration diagram. I  was mistaken thinking the image that had been posted was the calibration diagram. It looks like you’ll need to roll your own comps to figure out how to salvage your measure up- not insurmountable. Then figure out a way measure to the ARP in future setups. That’s why some people gravitate to fixed height tripods. I’ve used them but not really a fan. The can help for error trapping, though.

Posted by: @rankin_file

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Thanks @norman-oklahoma for posting the actual NGS calibration diagram.

Unfortunately, the diagram I posted is for the HEMA631, not the OP's HEMS631. The NGS antenna calibration page does not include a diagram of the HEMS631.  Nevertheless, the user manual for the BRx7 contains the diagram posted by the OP, and that diagram does note, somewhat cryptically, the ARP/BAM (Antenna Reference Point / Bottom of Antenna Mount) as being the reference point for vertical offset measurements. 

@rankin_file 

In the NGS calibration diagram, what is the piece protruding from the bottom of the S631? We have a 44 mm female quick connect that threads into the bottom of the S631. It connects quickly to a rover pole male connector or a tribrach male connector. It's similar to the one in the attached picture but it's not made by Trimble.

Posted by: @norman-oklahoma

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Nevertheless, the user manual for the BRx7 contains the diagram posted by the OP, and that diagram does note, somewhat cryptically, the ARP/BAM (Antenna Reference Point / Bottom of Antenna Mount) as being the reference point for vertical offset measurements. 

You mean ARP=BAM?

It looks like the RINEX converter successfully calculated the BAM using my 4.95' slant height.

According to rankin_file:

hypotenuse = 4.95'
opposite side = 78.5 mm (0.26')
adjacent side = 4.94'
subtract 54.7 mm (0.18')
4.94' - 0.18' = 4.76' (1.4520 m) as shown below

Thanks to rankin_file and Norman_Oklahoma. Have a great 4th of July.

Posted by: @field-dog

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It looks like the RINEX converter successfully calculated the BAM using my 4.95' slant height.

It knows what to offset is - from the antenna calibration.  OPUS still expects you to enter the measure up to the ARP. 

@field-dog Submit to OPUS once with 4.95 and once with 1.4520 and I think you'll find you get different answers for your point's elevation. I believe you must submit bottom of antenna mount instrument height in order to get the correct point elevation.

Posted by: @lurker

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I believe you must submit bottom of antenna mount instrument height in order to get the correct point elevation.

I'm sure I submitted the slant height, not the BAM, to OPUS. Will resubmit. Thanks.

There are times when I feel blissfully ignorant (by choice) on some of the discussions here.  I have reached the same stage in life as some of my old professors back in the day,  It was the introduction of computers in their case.  They were experts with slide rules and data tables found in various reference books.  Secretaries were the only ones operating keyboards (sans boards) in their day.

I challenge all readers of this comment to try to go eight hours while awake not using any form of computer, including Apple Watches and any kind of phone that is not hardwired and setting on a desk.