GPS 功能 31 CHAPTER Using the GPS Function
本章要点：FTX-1 加装选购件 FGPS-5 GPS 天线单元后即可使用 GPS 功能，开机自动搜星、自动校时并获取本机位置。本章说明 定位过程、影响定位精度的环境因素，以及与 GPS 相关的菜单项和定位信息显示单位的设置。
31-1 Enabling the GPS Function · 启用 GPS 功能
使用 GPS 功能需要选购件 "FGPS-5" GPS 天线单元。 Requires the optional "FGPS-5" GPS antenna unit to use GPS 信息可用于以下用途： the GPS function. 为经常联络的电台设定位置，之后在屏幕上显示各成 The GPS information can be used as described in the following examples: 员呼号对应的位置、距离等信息（详见另行提供的 《Operating Manual GM Edition》）。 The location can be set to frequently contacted 通过数据通信与其他电台交换位置信息和消息（详见 stations. Then display the position, distance, and other information for each member's call sign on the screen. 另行提供的《Operating Manual APRS (Refer to the separate "Operating Manual GM Edition".) Edition》）。
Exchange position information and messages through data communications with other stations. (Refer to the separate "Operating Manual APRS Edition".)
注意 / NOTE
FGPS-5 为选购件，随机不附带；未安装该天线单元时 GPS 相关功能无法工作。FGPS-5 接在 FTX-1 机身的 GPS 端子上。 The FGPS-5 is an optional accessory and is not supplied with the transceiver. GPS functions do not work without it. The FGPS-5 connects to the GPS terminal on the FTX-1.
31-2 Positioning Using GPS · 用 GPS 定位
FTX-1 开机时（需安装选购件 FGPS-5）GPS 接收功能即 The GPS receiver function is enabled (requires optional 被启用，随即开始搜索卫星，屏幕顶部显示 GPS 图标。 "FGPS-5") when the power of the FTX-1 is turned ON. The FTX-1 会根据 GPS 数据自动完成内部时钟设置和位置信息 satellite search will begin and the GPS icon will be shown 设置。 at the top of the display. The FTX-1 automatically obtains the internal clock setting, and the location information 捕获 GPS 卫星可能需要数分钟。 setting, from the GPS data. 当无法捕获 3 颗及以上卫星时，GPS 图标会消失；此
It may take several minutes to acquire the GPS 时无法定位，位置信息也不可用。 satellites. When three or more satellites cannot be acquired, the GPS icon will disappear. In this case, positioning is not possible, and the position information cannot be used.
关于"定位" About Positioning by GPS
所谓"定位"，是指根据卫星轨道信息和电波传播时间计算 "Positioning" refers to calculation of the current position 出当前位置。要成功定位，至少需捕获 3 颗卫星。 from the satellite orbit information and radio propagation 如果定位失败，应尽量远离建筑物，把 GPS 接收天线置于 time. At least 3 satellites must be acquired for successful positioning. 天空开阔的位置。
If positioning fails, move away from buildings as far as possible and position the GPS receiver in an area with open sky.
31-3 Positioning Errors and Long Idle Periods · 定位误差与长时间未使用
测量环境可能导致数百米的定位误差。在条件良好时，仅 The measurement environment may result in positioning 用 3 颗卫星也能成功定位。但在下列恶劣条件下，定位精 errors of several hundred meters. Under favorable 度会下降，甚至无法定位： conditions, positioning can be performed successfully using only three satellites. However, under the following poor conditions, the positioning accuracy can decrease, or positioning can fail:
表 31-1 会导致定位精度下降或定位失败的环境 Table 31-1 Environments that degrade or prevent positioning
环境 影响 Environment Effect
Between tall buildings 精度下降 / 定位失败
Narrow paths between buildings 精度下降 / 定位失败
Indoors or near large buildings 精度下降 / 定位失败
Between trees, such as in forests or woods 精度下降 / 定位失败
Under elevated roads or high voltage power lines 精度下降 / 定位失败
Inside a tunnel or underground 无法定位
Through heat reflective glass 精度下降 / 定位失败
Areas with strong magnetic fields 精度下降 / 定位失败
购机后首次使用 GPS 功能，或长时间未使用后再启用时， When using the GPS functions for the first time after 可能需要几分钟才能捕获卫星。此外，若 GPS 功能已关闭 purchase, or when it has been unused for a while, a few 数小时，重新搜索卫星也可能需要几分钟。 minutes may be required to acquire the satellites. Also, if the GPS function has been turned OFF for several hours, a few minutes may be required to search for satellites.
31-4 GPS-related Menu Items · GPS 相关菜单项
表 31-2 GPS 相关菜单项 Table 31-2 GPS-related menu items
菜单项 可选值 默认值 说明 Menu item Available values Default Description
GPS OFF / ON OFF GPS 功能的开启 / 关闭
GPS PINNING OFF / ON ON ON：本机移动速度为 0 时锁定经纬度数据； OFF：速度为 0 时仍持续计算经纬度
GPS BAUDRATE 4800 / 9600 / 19200 / 38400 / 9600 bps GPS 通信波特率 115200 bps
GPS TIME SET AUTO / MANUAL AUTO AUTO：内部时钟的时间数据自动取自 GPS； MANUAL：不使用 GPS 时间，以手动设置的 内部时钟优先
MY POSITION GPS / MANUAL GPS 选择本机位置由 GPS 自动获取，还是手动输入
MY POSITION LATITUDE N 00° 00.00' (00") — 手动设置本机纬度
MY POSITION LONGTUDE E 000° 00.00' (00") — 手动设置本机经度
[OPERATION SETTING] → [OPTION] 组中包含 GPS、GPS PINNING、GPS BAUDRATE；[EXTENSION SETTING] 组中 包含 GPS TIME SET 与 [MY POSITION] 下的 MY POSITION、MY POSITION LATITUDE、MY POSITION LONGTUDE。
31-5 Units Used for Position Information · 定位信息的显示单位
表 31-3 [DISPLAY SETTING] → [UNIT] 单位设置 Table 31-3 Unit settings under [DISPLAY SETTING] → [UNIT]
菜单项 可选值 默认值 说明 Menu item Available values Default Description
POSITION UNIT MM.MM / MM.ss MM.MM 经纬度"分 / 秒"的显示单位；MM.MM 以 1/100 分显示，MM.ss 以秒显示
DISTANCE UNIT km / mile mile 距离单位
SPEED UNIT km/h / knot / mph mph 速度单位
ALTITUDE UNIT m / ft ft 海拔高度单位
HAM 实战 · 让 GPS 尽快锁定 FIELD NOTE
野外设台时，把 FGPS-5 放在头顶无遮挡的位置（车顶、帐篷外、三脚架顶端），而不是压在电台机身旁边或金属桌面上—— 金属平面和机身自身的射频场都会明显拖慢首次定位（冷启动）。抵达现场后先开机再架设天线，让 GPS 在架天线的几分钟里 完成搜星，等 GPS 图标稳定后再开始 APRS/GM 业务。若 [MY POSITION] 设为 MANUAL，即使 GPS 已定位也不会自动更 新本机位置，固定台与移动台切换时要记得改回来。另外 [GPS PINNING] 默认 ON，车辆停在原地时经纬度被锁定，不容易 出现坐标"漂移"，这个默认值一般不需要改。 In the field, place the FGPS-5 where it has an unobstructed view of the sky (roof of the car, outside the tent, top of a tripod) rather than next to the radio body or on a metal table — metal surfaces and the radio's own RF field noticeably slow down a cold first fix. Power the radio on first and then put up the antenna, so GPS finishes acquiring satellites while you are still setting up; start APRS/GM operation only after the GPS icon is stable. If [MY POSITION] is set to MANUAL, your own position is not updated automatically even when GPS has a fix — remember to switch it back when moving between fixed and mobile operation. [GPS PINNING] defaults to ON, which holds latitude/longitude when your speed is zero and prevents coordinate "drift" while parked; there is normally no need to change it. （社区 经验）