The GPS locks quickly and there are options to view how many satellites are in range, store location, send your location and receive location.
GPS menus are in the APRS and DISPLAY sections of the [SET] menu as well as being accessed with the [DISP] key. [SET] <APRS> <DATUM> defaults to WGS-84, <POWER> is On or OFF. With a 20% power increase with the GPS on, turn it off to save battery. <GPS TIME SET> pulls the accurate time from the satellites. <GPS UNIT> Sets the lat and long units (.MMM is the APRS standard - meaning degrees and minutes plus decimal minutes).
[SET] <DISPLAY> <GPS INFO> shows you your location coordinates, altitude, speed and an accurate time (scroll using the tuning knob). The GPS doesn't hold lock as well as those in mobile phones (although they cheat using the internet often) but it does find lock quickly when it can see enough sky. [ENT] shows a bar graph of what satellites are visible (and how strong).
As mentioned the GPS once locked will show your location, speed, direction, altitude and the time.
If you are travelling you can store waypoints to the SD card [SET] <CONFIG> <GPS LOG>. Turning the log on starts a new log file. The GPS will store waypoints at intervals you chose, to the SD card so at the end of the journey you have a log that can be overlayed on a map. (Move the SD to a PC using a suitable card reader, data is stored in the GPSLOG folder.)
Before setting out store where you are -you can store three locations called *, L1 and L2 (the manual refers to *, L1 and L1). The Backtrack screen appears on pressing [DISP]. Select <MY> with the knob and [ENT]. Chose *, L1 or L2 with the knob and [ENT] again to copy 'mylocation' there.
To find the old location again, [DISP] and turn knob to *,. L1 or L2 - the arrow points to the direction of the waypoint. [DISP] will now toggle between waypoint direction and frequency display.
When in digital QSO the digital voice signal will also be encoded with GPS data so long as the far station has their GPS on. Press [DISP] and select [YR] with the knob ('your' rather than 'my' location). [DISP] turns it back to frequency display.
You can save a YR location into *, L1 or L2 just as you can a MY - giving you a semi permanent pin in the distant location to navigate to.
The GPS positioning data is also encoded and received when using FCS reflectors via the DV4mini dongle.
The GPS will feed NMEA strings out of the data port, letting the radio feed location information into PC and other mapping systems in real time.
APRS is copyright Bob Bruninga. APRS activity in the UK has fallen off into a series of small groups of stations but locally there can be lots of traffic.
The Yaesu has an APRS software function that will beacon on RF location packets, receive other RF packets and send and receive messages over APRS. The Yaesu APRS is more applicable to open air, SOTA or walking radio in a local area although the Yaesu GM function duplicates some of this functionality in a Yaesu specific way.
APRS on a tiny screen and keyboard is a challenge - it's really a mapping system after all - the radio stores and will show you a list of stations' details received, when and if you 'open' the entry in the list you get more information like speed. altitude and direction as well as the type of item is in the list (a mobile, a fixed station or an object for example).
Press  to toggle between stations and messages. From the message list use [GM] to open the message editor, and use [ENT] -for 1 second - to send. It works and it fits in your pocket. I have already found several stations on APRS around me that I had missed before. Kudos Yaesu!
Using APRS - press [SET] then [APRS]. From there [MODEM] turns APRS on at 1200 or 9k6baud -typically 1200 on 2m. [APRS MUTE] stops you hearing the packets. There are 4 [BEACON] variables, [CALLSIGN(APRS)] to set (use -7 for handheld suggested) and the defaults otherwise are ok to start with. [APRSringer] will select which beeps you want.
I would recommend the Android application APRSDROID for licensed amateurs as the mapping function works really well.
When using APRS typically one band of the dual band radio is on APRS (it has to be VFO B on the FT1XD) and the other on an FM channel. Some folk put the FM channel into their beacon so observers on APRS can give a local a voice call.
Voice-Alert is an advance on this. By setting your PL tone on transmit on your APRS vfo to 136.5Hz and setting 136.5Hz receive CTCSS tone you can have the volume up and not hear APRS packets (as all digipeated or node origin packets will not have a PL tone) unless the packet is being heard direct from the origin transmitter. If you hear such a packet, you can call on the APRS frequency and ask the station to QSY to an FM channel for a local QSO. So even if they are scanning on their FM vfo, they will hear your request for a contact.
Other tones are used outside of Europe. More details are here.
HOWEVER on the FT1XD radio, you cannot enable the APRS modem and have a CTCSS/PL tone set on the same (B) VFO. So that's that then, no voice alert.
The Yaesu APRS system does not permit access to the TNC part and so 'command mode' operation for ISS DIGIPEATING is not available, and you cannot use the radio like an external TNC as per Kenwood.
The beacon mode will permit you to have location packets digipeated by ISS without acknowledgement (it's connected packet that slows ISS communications right down). Set the DIGI PATH to ARISS, WIDE1-1 (that goes in as WIDE1 with a -1 ssid) and beacon manually if the channel is quiet, no more often then once per minute (remember you may hear no activity locally but if your packet arrives with another at the ISS neither will be decoded hence the need not to flood the channel).
I plan to use the FT1XDE in monitor mode during some passes to start with and see if it coincides with packet activity. [F][S.LIST] - don't use messaging vis ISS (they have three Kenwood APRS radios on the ISS but the messaging mode is just too inefficient with bandwidth).
Below is an animated GIF showing the station list screen with the first three station entries opened with [ENT] and scrolled with the tuning knob.
ISS APRS was received on 145.825Mhz. Beacon set to MANUAL (so it doesn't beacon). I didn't transmit on this pass.
The station list shows
1:IS0EBO-4 located 1012miles distant and using a TM-D700. The Lat Long is included and then 73 FROM SPACE. Nice touch.
2:F4ECA 618.6 miles, Fixed station.
3:G7HCE-7 using a TH-D72 at 170.2 miles away. '5watts into a whip antenna'.
*NOTE* The Ericsson VHF radio failed in the ISS and a replacement was launched to it in February 2017. Temporary Digipeating was is on 437.550 on their UHF equivalent details here , however this returned to 145.825 in August 2017
Having displayed a station listing, highlight a station likely to be able to receive messages (such as using a Kenwood or Yaesu APRS tranceiver) and press [ENT] to bring the station details on screen.
Send a message to this station by pressing [GM] -this shows the message EDIT screen with the destination callsign filled in (but editable).
Type the message using the keypad (eg press  twice to get a b) - use  to enter a space, [F] to delete left and pressing [A/B] repeatedly cycles the [V/M] button function through CLEAR, CLEARALL, and back to EDIT.
Send by long pressing [ENT] - the message is added to the message list and is sent 4 times unless acknowledged. Find the message list from the station list, press  to toggle station list/message list.
It's easier to send messages from a phone app like APRSDROID mind you, and the Yaesu system is harder to use than the old Kenwood TH-D7 one was.
Intended for simplex channel operation, the GM function allows you to create lists of amateurs and be alerted when they are in range. There is also a text message function. I haven't yet used GM - maybe at a radio rally? It lets you group people you know. More here when I get there...