HI：height-of-instrument天线高信息

Notch：槽口

DH：direct height直高

SL：slant height斜高

ARP：the antenna reference point天线参考点

BPA：bottom of preamplifier 前置放大器底部 (与ARP、PAB等价）

BCR：bottom of choke ring阻流圈的底部

TCR：top of  choke ring阻流圈的顶部

L1/L2：L1/L2 phase centre L1/L2相位中心

BDN：black dots in notch槽口处黑点

HHK： height hook

BGP/MGP/TGP：bottom/middle/top of ground-plane casing 天线罩外边沿下部/中部/上部

BCB： bottom of center belt 不理解啊

TGN/BGN：top /bottom of ground-plane cover in notch 天线罩槽口顶部/底部

HGP： top outside of holes in ground plane

（ correct SLAGP to SLHGP ）

ARP abbreviations
=================
BAM: bottom of antenna mount
BCR: bottom of chokering
BDG: bottom of dome ground plane
BGP: bottom of ground plane
BPA: bottom of preamplifier
TCR: top of chokering
TDG: top of dome ground plane
TGP: top of ground plane
TOP: top of pole
TPA: top of preamplifier

大多数接收机天线中：ARP=BAM

组合实例：

（1）DHARP：直量至相位中心参考点，即前置放大器底部。
（2）DHBGP：直量至天线盘底部。
（3）SLBGP：斜量至天线罩外边沿底部。
（4）SLMGP：斜量至天线罩外边沿中部。

（5）SLTGP：斜量至天线罩外边沿上部。
（6）SLTGN：斜量至天线罩槽口顶部。

（7）SLBGN：斜量至天线罩槽口底部。

个人理解：分体机对应槽口GN，一体机对应天线罩外边沿GP

更多细节参考：

http://epncb.oma.be/ftp/station/general/antenna.gra

The file antenna.gra provides important physical features of receiving

antennas:

- the position of the antenna reference point (ARP) to which the phase center
 correction values in the corresponding IGS antenna phase center model
 (currently igs08.atx available at ftp://igs.org/pub/station/general/) refer.
 The ARP is preferably an easily accessible point on the lowest non-removable
 horizontal surface of the antenna. Typically, the ARP coincides with the
 axis of attachment of the antenna to a monument or surveying instrument.

- the definition of the north reference point (NRP), i.e. the element of the
 antenna that has to be oriented toward the true north direction.

- antenna dimensions (in meters) or other measurable features.

At the end of the file, a machine-readable quick reference section is given
for convenience. Antenna names are defined in the file rcvr_ant.tab (also
available at ftp://igs.org/pub/station/general/). The IGS Central Bureau, with
support from the IGS Antenna Working Group, maintains this list and should be
contacted at support @ igs.org with any comments.