GPS usage in Hang Gliding and Paragliding

http://stpxml.sourceforge.net/skygod/Navigation/gpsinfo.html

By Ulf , last updated November 2009

"I am here - where the hell are you ? "

Ever tried to describe to your recovery mate where you ended up? Can become quite confusing. And , if you are married, can get you divorced. Describing to your recovery where you landed, can be made easier if you can pass on to them your GPS landing coordinates. Provided your recovery crew got a map that has a coordinate grid and knows how to apply coordinates. Or also provide them with a GPS and hope your recovery knows how to use it.

When flying, I recommend you set your GPS pointing to GOTO takeoff. And report approximately every 10 km , that you are now x kms from takeoff on a BEARING of whatever.
This enables other pilots who fly on the same setting to get a quick idea where you are in relation to them. And helps the recovery to get a rough idea of your position. Reporting your coordinates while you are flying is a waste. No one can write them down fast enough or figure out quick enough where you are.

Once landed, don't phone your mates and tell them that you are 52 km from takeoff at whatever coordinates. As a pro you send an SMS. Less chance for your recovery to write it down wrong. And send the coords in a fromat of degree , minutes, decimal minutes. SMS Example

Ulf down and safe, S 30 29.455 E 028 22.345 19 km.

Pilot name - in case the recovery has to recover multiple pilots

down and safe - if that is not mentioned we assume an emergency and you had no time to waste because you are bleeding to death

An emergency SMS of me would look like this Ulf , S 30 29.455 E 028 22.345 in case I only got a few seconds before I fade out

The coords in degree and decimal minutes - because maps cater for degrees and minutes. Before driving off, a recovery driver first checks

on a map the rough location where to go to. Or in an emergency we have to pin point the crash location first to get an idea how to best get there.

Decimal minutes, no seconds. Minutes only gives you about 1.8 km or less on accuracy. Not good enough.

If you give your coords with 1/10 of a decimal minute you are providing an accuracy of 30m.

And Laura insists I also have to provide the distance from launch. To get an idea how long the trip will take to get me back.

If you can afford it, get a Kenwood Radio (for around lots of Rand ... ), that interfaces with your GPS in flight. And provide for the recovery crew a base station. The Kenwood will transmit in regular intervals your position , speed and heading to the base station. Up to 15 pilots can be monitored by the base station. Or get a Garmin Rino.

Tip for the stressed recovery driver who is driving, listening to the 2m radio, answering the cellphone, hunting for pen and paper while receiving coordinates from a landed pilot ....: If you have to enter a new waypoint in a hurry .... MARK ENTER your current location, then EDIT the current location with the provided coordinates. And then GOTO to it.
Unfortunately we do not fly very far. You current location coordinates are close to the pilot landing coordinates. You only will have to modify a few last digits of your current location coordinates to change them to the pilots coordinates. Much faster using your current location and changing it. Compared to punching in a new waypoint from scratch.

More tips for recovery driver

You receive an SMS with the landing coordinates of a pilot.

Wrong approach: Punch in the coords on your GPS , hop in the car, and drive in the direction that the arrow points to.

Correct approach:

Phone or SMS back to the pilot and confirm if he still requires recovery. Or if someone else is already fetching him. Or if he got a lift.
Confirm that he is still at the same position
Ask him for any advice, directions, recommendations... how to get to him.
Ask him for any obvious landmarks close to him, like triple power lines running parallel to the road. Or a farm name.
Confirm if he got a radio and on what frequency he is listening
Locate the coords on a map and then make a plan what roads to take
Take along a GPS, cell phone and a radio
Check how full the tank is

Bad example of a recovery gone wrong

How to use a GPS to improve your casual cross country flying

Do not rock up on a super XC day on takeoff with your brand new GPS and expect any of the other pilots to set it up for you.
Make yourself familiar with the goodie before you want to fly.
Or have someone explain it to you once you sit in turkey waiting for recovery, or over a beer after a days flying.
You need to understand the following functionalities

How to Enter your takeoff as a waypoint
Set your GPS to use GOTO to your takeoff
Modify the Display Options, on newer GPS, to show Ground Speed, Bearing, Distance
Figure out how to switch around between the different pages
Define your track sample rate
Know how to Zoom in to see your track in a 400 meter resolution
Set your GPS for WGS84, at least for South Africa.
And set your GPS , in South Africa, to the Deg mm.mmm format to be used as a common coordinate format.

Maps in South Africa got on the side degrees and minutes. Using the Deg mm.mmm format makes it easy to locate a position on the map.

And make sure you fly in km/h , km, meters. Using Nautical miles or statue miles will take you much longer to see that 100 from takeoff...

What to do before taking off

Mark your takeoff position as a waypoint. Accept the system assigned identifier. Like 001. Or if you got the time, give it a name. For example THEDAM or RSTNBG. And set your GOTO to your current takeoff site.

Make sure your track memory is cleared.

When I arrive at a site and kit up I clean out all my waypoints and only Mark Enter today's takeoff position. Which is 001 in a GARMIN. And then GOTO 001. And clean out the Track log .

Check if you are in WRAP or FILL or OFF Mode.
OFF mode is a big NO-NO. OFF means no track are collected at all.
FILL means your track gets collected until the memory is full and then stops.

For casual cross country you should be in WRAP mode. In case you forget to clear the memory you still record the flight.

Now you got 2 choices,

either you want to keep a full track log of your flight and you fly on a 15 seconds sample rate
or you are keen to use the GPS for backtracking to a lost thermal and use a 1 second sample rate

And avoid using Battery Save mode, unless you fly with a cheap eTrex or old eMap.

Option 1 - Collect a full track log for a XC flight

Got one of those old GPS12? Then switch off your GPS while on the ground.

Newer GPS makes, with 10000 points, as long as you are in WRAP mode and 10 seconds sample rate, keep it switched on.

You can takeoff without having your GPS switched on. To save memory and battery usage.

Want to fly distance? Then better make sure you got the wind from the back.

Once airborne , and in case you manage to be up at cloudbase/inversion or ceiling, and decide it is time to go cross country, then make a decision which direction to go, based on the drift of the thermal. Reaching the top of the thermal switch on your GPS. A GPS 12 remembers that you had set the GOTO to 001 ( for example) and all you have to do, is press ENTER to activate 001 again. If you did not do this before launch you will battle with gloves on to scroll through the list and choose the correct waypoint. Assuming you selected the correct waypoint the GPS will now give you your distance from takeoff. As you are heading off to start your cross country flight and make sure the arrow points straight back, indicating that you fly away from your start point and your distance increases.

The GPS will give you an idea on your ground speed. Zig zag a bit when leaving cloud base, deviating plus / minus 30 degree from what you think the drift is, to figure out the best ground speed. Flying trim speed ( let's say 38 km/h) I expect a reading of around 50 km/h or more for an average cross country day. If I see less, I have to decide to go some other direction to see if I get more ground speed. Or opt for a triangle or out and return flight.

Once switched on, the GPS is collecting in the track memory your position in regular intervals. The track log can after the flight be downloaded with a data cable to a PC and then be used as proof to verify your distance claim.

Got a recovery following you? You are probably already 10 to 15 km away by the time he or she starts driving. Sharing with them how far away from takeoff you are, will give them an idea from where on they should slow down and start looking for you in the sky. And of course it feels great to let the rest of your buddies, who happen to turkey, know, how many kms you have managed while they pack their kit back in the bag.

Now we have to understand what bearing BRG and track TRK means. Track is the direction that you are heading at the moment. If you are heading straight North, then the track will be around 360. East is around 90, South around 180, West 270.
Bearing BRG is the direction from where you are at the moment towards the waypoint that you activated with GOTO.
Example, you marked your takeoff as 001 and set the GOTO to 001. Flying away to the east, your TRK will display 90, while your BRG pointing back will be 270. When you thermal your TRK value will change all the time, going around in circles, while your BRG value should stay the same.

In case your recovery got a GPS, they should also MARK the Takeoff and then set their GPS to GOTO takeoff.
I do not give GPS coordinates in flight. They are cumbersome, block the channel too long, easy to be jumbled up, have to be repeated, and require the recovery crew to hunt for pen and paper while busy driving and finding their way around in unknown places. I recommend to use Distance and Bearing.
As the pilot, I just tell them that I am now 25 km from takeoff on Bearing 245. "ULF 25 km Bearing 245" instead of " RECOVERY ULF I am now at S 25 45 Minutes East 21 36 Minutes" and you get as a response " Sorry, missed that, repeat "
Using Bearing BRG your recovery just has to make sure their GPS shows the same bearing and distance values and you should be somewhere up there.
In case your recovery is really jacked up, he/she will add or subtracts 180 degree from your bearing and thus gets the direction they have to drive from takeoff. Or they use a map and plot from takeoff a radial with your bearing-180 and then get the apply on it the distance and they got you position pinpointed on the map. Next step would then be to make a plan which roads to take and how to get to you.
And when I am low and it looks like I will land soon, I give out a short call, like " Ulf going down 9km from takeoff on Bearing 72.” I honestly do not have the time to switch the display to the coordinate window, try to read those figures, while I rather focus on finding some lift or a decent landing spot.

Option 2 - high sample rate to find lost thermals

If you are not keen to collect a full track log of your flight and finding a lost core of a thermal is more important to you, then set your GPS to a 1 second sample rate. And have your GPS switched on while taking off.
And a ZOOM of around 500 meters. Then you can use the GPS track plot to help core a lost thermal. This works when you have a high sample rate , let's say every 1 or 2 seconds, but you gobble up memory this way. And ( not confirmed) you use more battery power. If you fall out of a thermal, head back to your last turns as shown on the display. In most cases the thermal is still there.
But do not focus solely on your GPS. Rather look around, feel the wing, and relate your position and drift to the ground... Not a nice idea if every pilot from now on stares only on his GPS and listens to his vario and does not look around. Scary ...

If you got a GPS with a limited memory and want a high sample rate, consider adding a datalogger to your gadget collection. to collect the full track. Or invest into one of those new fancy Vario/GPS combinations.

Determine your trim speed and wind speed with a GPS

If you want to find out what your trim speed of your glide is, simply fly into wind, until the GPS is showing the slowest ground speed, hands up, no toggles, no speedbar. Let's say the GPs shows you 15 km/h.
Then turn around, fly downwind, again hands up, no speedbar and find the top ground speed. what might be 60km/h.
Your trim speed is then ( 60+15 ) / 2 = 75 / 2 = 37.5 km/h
And the wind speed is (60-15) / 2 = 45 / 2 = 22.5 km/h
For the maths behind this see Equations.

Cross-country Flight Verification

After your cross country flight, once landed, mark your landing position and memorize your GOTO distance from takeoff.
By the way, this distance tends to increase, as time goes by. Similar phenomena can be found in the size of a fish caught by a fisherman....

Get out your cellphone, and SMS your landing coordinates that you can read from your GPS.
My SMS looks like this .... Ulf S 26 45.123 E 028 36.123. And I have prepared a template now that says Ulf down and safe S . E .
I tend to send it off to a multitude of potential recovery drivers. Since I never know who got away and who is looking forward to drive the famous Ulf Mobile.

If you are keen to preserve your track after landing, switch off your GPS . Or switch the track recording to OFF. Or put your GPS into simulator mode.
Otherwise the GPS keeps on recording and filling up your track memory. And if you have set your GPS to wrap mode it will overwrite your first 100km flight data.

If you had your GPS set to a 1-2 second recording, then most of your flight track log is anyways lost on a low end GPS.
If you fly with a 15 second track log on a GPS 12 and use WRAP mode, then your complete should be in the track memory.

For a GPS 72 use 10 seconds and WRAP mode, 4000 points, 6 a minute, 360 an hour, 11 hours.

Do not TRACK/SAVE your flight in a GARMIN. You loose a lot of trackpoints this way and render the flight unusable for flight verification.

What PC software can I use to see my flight?

You can use a PC and software like Fugawi, GPSVAR http://www.brauniger.de, OziExplorer, SeeYou www.seeyou.ws, Strepla, CompE http://www.compe-gps.org/ , Soar www.aeroclub.student.kuleuven.ac.be/lvzc/soar , MaxPunkte www.flugplatz-beilrode.de/dm/home.html,Gartrip http://www.gartrip.de/ , to download your flight from the GPS track memory and display it on the PC monitor. If you only want to download your track data with no visual display of your track, , use the Gardown program http://www.anali.demon.co.uk/gardown.htm or or www.poly-electronic.ch/gps-tools.htm

And if none of those work, try http://www.gpsbabel.org/ to convert whatever you got to whatever you need to get in or out of your GPS.

To make your own data cable , see http://www.garmin.com/support/faqs/39.html or http://pfranc.com/projects/g45contr/assemb.htm

If you got a GPS with 3D tracklogs and you want to analyze your flight, and you are familiar with JAVA, you might enjoy the T3D2 code from http://sourceforge.net/projects/t3d2

If you want a logbook functionality, and you know JAVA, have a look at JFlight. http://jflight.sourceforge.net/index.html

For a casual beginner XC pilot a 2D track log GPS, like the GPS 12, Gartrip might be good enough.
With Gartrip one can download and plot flights. Gartrip gives distance from takeoff and speeds.
And store the track data in gardown .gd format. Most software packages to analyze GPS data can read it.
But newer GPS also have altitude data. While gardown format does not store altitude data. In that case try to save it as IGC.

As a serious XC or competition pilot you will have to get a GPS device that can do 3D Track logs.

If MaxPunkte http://www.flugplatz-beilrode.de/maxpunkte/download.html or SeeYou http://www.seeyou.ws/

can be used for the OLC http://www3.onlinecontest.org/olc-2.0/para/index.html . OLC is the Online Contest. Pilots world wide can send their track logs to this website and get a score for it.

OLC submitted flights can be used for FAI Badge claims.

GPS in Competition

GPS have replaced the traditional photo verification during the dawn of the new millennium. Competition organizers now provide you with GPS coordinates for turnpoints and goal. And flying a task has become , um, well,... easier, more complex, more confusing, simpler, ... ???

Remember the old days where you had to find a house with a red roof, or a radio mast ?
Now we got virtual turnpoints. Or, even better, invisible turnpoints. Virtual means one can see it, but is not there.
Now we are dealing with turnpoints that are there but one can not see them. Only your GPS might tell you that you are getting there.
And no more starttarp that gets changed on the ground. Start lines can now be 20 km away from some point and you have to be on one side of it in a certain time period. Idea is to be close to that invisible start line , just before it opens, and very high. Minor problem.. you can not see it, unless you keep an eye on your GPS, which happens to be tucked away in one of your side pockets,.. bummer.

Position and velcro attach your GPS so that you can see it in flight. When you plan to fly in a competition be familiar with the following GPS capabilities:

How to define a route and activate it
How to add a Waypoint by hand
How to clear a track log and change the settings for a track log
How to change the track sample rate
How to change the interface mode to GARMIN/GARMIN (for example)
How to change the batteries
How to manipulate the track display area
How to mark a waypoint
How to switch off and on the track recording
How to modify the contrast of your display
How to set the coordinate system, WGS84, UTM, deg/min/sec,..

RTFM , read the !@#$% manual

And when you fly a GARMIN, make sure you get into the 400m radius! Simply because the arrow points to the next turnpoint does not mean you got into the cylinder.

In case you keep important waypoints in your GPS download and save them at home before the competition.
Especially if you have a lot collected. The GPS scoring code has to read all your waypoints to find the one which determines your pilot number.
The more waypoints you got collected the longer it takes to score you.
And you run the risk of having one of your waypoints overwritten by one from the competition.
Plus you disadvantage yourself at briefing, while defining the task of the day in your GPS. While everyone else got maybe 20 waypoints to work with, you have to scroll through your big collection. And might define the wrong route. Everyone else flies to goal, while you fly towards your favourite dive spot.
Or you got a T01045 from Barberton, a T01079 from Dasklip and a T01094 from Bulwer in your GPS. While every one just defines the route with one T01, you have to remember which T01 is the correct one for this competition. Might explain why you got a 462 km task and everyone else got a 44 km task as the route of the day....

Clear all waypoints before a competition.

When you arrive at the competition, at registration, make sure you get GPS loaded with the official turnpoints and your pilot number.
Do not expect that this facility is at hand on take off. If you are a late comer and missed the upload, then you will have to punch in the days waypoints by hand.

Make sure the official waypoints are in your GPS

The task of the day will be given to you as a route. Which you will have to enter by hand on take-off after the task briefing.
Sometimes the window will be opened immediately after the briefing. He who got in the route the quickest might be the first to launch and first in goal....
By defining a route in the GPS, the GPS will point out to you how far and where the next turnpoint is.
Confirm the total distance of the route with the one on the task board. If it matches then you should be more or less ok to fly in the right direction.

In the old days before GPS, as a pilot in a competition one had to make sure that you were in a certain position and distance from the turnpoint.
By taking a picture with a camera from within the FAI sector of a turnpoint.
Cameras and FAI sector now got replaced by GPS and circle / beer can turnpoints.

Now only the distance from the turnpoint is important. But one has to get closer to it. Instead of 1 km radius it tends to be now 400 meters.
All your track log, that gets collected inside of your GPS, has to show, is one track point closer than 400 meters from the turnpoint.
The 400 meter comes from a GPS 12 setting, which only got a limited options of screen displays.
One is a 400 meter circle. In a competition, set your screen to the 400 meter display.
When you see your track crossing over the 400 meter radius then you know you are close enough to get the turnpoint accepted.
But wait! With an ordinary GPS 12 , set to a 15 second sample rate, one has to spend 15 seconds inside that circle to make sure you got a trackpoint collected in your memory. Newer GPS or the use of Dataloggers, like the Log_It , will give you an advantage to those who have to spend their 15 second in the circle. If you got a Garmin 72, 10 seconds are ok. What happens if you set it to 2 seconds, … see http://flygirl.co.za/content/view/113/55/
But if you fly with a eMap, or some other automatic sample rate device? Ask the organizers if you are allowed to switch it off in between turnpoints .

Define your GPS Settings to be setup optimal for the day's task

Goal can either be a goal line or also a circle. Goal lines make it easier for the public and organizers to see who was first.
Using a goal line , one has to make sure that the goal marshals put the line exactly on the correct GPS coordinates.
In case you get to goal, fly straight over the goal line to have a clear track sequence that shows when you crossed the line.
If you can , switch off your GPS 15 seconds after crossing the line. To avoid any memory wrap and clog up the goal crossing track display..
Loose height away from the goal line. In case your track log is still on and you keep crossing the goal line multiple times it becomes a messy picture to analyze in case there is any queries afterwards of who came first.
If the goal is somewhere out in the sticks, and the goal marshall crew is either not at hand or is not fast enough to get there, one can still try a "virtual goal line".
Which makes it difficult for the pilot to determine where the goal is. One can follow the arrow on the GPS until it swings around pointing back.

The other goal option is to use a goal cylinder. Which makes it visually difficult to see who came first.
Not very spectator and media friendly. As a pilot , in final glide to goal, take into account the extra 400m that you do not need to glide.
And if necessary run the last few meters if you are not sure if you crossed the line.

Once you got to goal or landed switch off your GPS. To save your track from overwriting. With GARMIN do not use the Track/Save option to save your tracklogs.

By using the TRACK/SAVE option one reduces the number of tracklog points. And afterwards the tracklog might be missing the turnpoint crossings.

I repeat ... Do not use TRACK/SAVE.

In case there is a need to switch on your GPS after your flight, better deactivate the track recording.
Like when there is a need to get direction to recover another pilot after down and safe time.
Switching on your GPS then and collecting track logs after feet on the ground time can be interpreted afterwards by the code that you are still flying.
And get you no score. Repeat, to be really safe and protect your track log, switch off the track collection mode.
But remember to switch it on the next day again from OFF to WRAP or FILL.

Recommend WRAP

Using FILL mode, your GPS will switch to OFF mode once full. And stay in OFF, even when you clear your track log. You have to switch it back to FILL or WRAP.

Protect your track log

When you hand in your GPS for scoring, keep it off until the GPS gets connected to the PC and you get told to switch on.
No good to collect track points of your progress in the queue in the meet center while overwriting the beginning of your track.

Give your GPS some individual look

Have some sticker or label with your pilot number on your GPS. Some scoring code can process multiple GPS at the same time.
The poor operator can be quite stressed and in the chaos your fancy GPS 12 MAP , which looks very similar to an old GPS 38, can get mixed up.
Or there is some computer hiccup and you have to leave your GPS overnight with the scoring staff.
More likely, the pool and the pub is calling and you add your precious flight instrument to a stack of piled up similar looking instruments to get processed .
Why wait in the queue when you can enjoy a swim and a beer and collect your processed GPS later.

PID error when downloading a track

When you have a GPS with a high sample rate, like an eMap or GPS 3 Plus on a 1 second rate, then you can confuse the scoring code.
The GPS dialog tells the computer that right now it got x track points. Computer says ok, give them to me.
For each trackpoint sent there is an acknowledge and a sequence counter incremented. The download takes around 30 seconds. And at the end, the GPS is sending more than the initial reported track points. Resulting in some communication confusion between PC and GPS. Switch the track sampling to OFF to avoid this.

Why rely on the track ? Why not allow the pilots to hit MARK Enter as proof that they have flown the task of the day?
Marked waypoints can be edited, created afterwards by hand or PC programs. And are in general not accepted as proof for flight verification.

No battery lives forever

So, now you have handed in your GPS and you got your score. Time to take out those batteries and get them recharged or put in new batteries.
Assume your batteries will only last for one flight. Keep your track log in case there is any problems with the scoring people. Only clear your track log the next day on take-off at briefing after you have seen the results and you are happy with your score. The newer GPS range with only 2 batteries die faster when having a high sample rate. In 2004 I recommend rechargeable NiMH with 2300mA capacity.

Write the day's task onto your GPS

If you purchased a protective cover, you can use an erasable koki pen to write the days task and times onto your GPS or Vario cover.
If you write it on the top side you run the risk of wiping,erasing,clearing your info by accident.
If you can write in mirror mode, take the cover off and write it in the inside of your cover. This way you can not clear it easily.
Another approach is to ave some yellow post-it stickers. Use the post-it yellow sticky paper and stick it into the GPS or Vario cover.

Using GPS for flight verification in competitions has improved competition scoring. For an 80 to 100 entrants competition now one needs 2 hours to process all pilots and have the results. Before it took at least 12 hours of volunteer work to get out results. Which enables the competition organizers to keep down costs and stress levels. Sounds great? Yeah, you just listened to the sales pitch. What was not mentioned is that those who run the computer show are in for some fun and games and long nights. One requires know how, PC literate staff and a good preparation of the systems to have a smooth run competition.

In South Africa we use a GPS Turnpoint Verification program called TP.
The code is for free and can be downloaded from http://sourceforge.net/projects/gpstp .

Other programs available on the web for competition scoring can be found at http://www.cquest.org/cq/gps/gps.html , http://www.compe-gps.org/ or from http://www.ozemail.com.au/~zupy/gps/ .

Before a competition that uses GPS verification takes place the following information has to be given to the pilots.

Recommended GPS-12 settings:

Same time zone settings for all pilots, otherwise your takeoff time, start tarp time or goal time is out in the waypoint fields can be out.

For South Africa that is +2.

For South African competition set the Track sample rate for a GPS 12 with 1024 memory track points, to every 15 seconds, 240 per hour. With 1024 track memory this should last for a 4 hour flight .
In Europe use a 20 second sample rate, there you fly longer tasks.
Decide if you use WRAP or FILL mode. Make sure you are not on OFF.

I suggest WRAP mode. In case one does not clear the track log before takeoff.

But if your GPS is not switched off after landing WRAP mode can wipe out your flight
When you are sure you clear your track log each day, then you can use FILL mode.

Fill will have the advantage that it shows that you took off and had all the turnpoints, when your memory runs full before you get to goal.

Actions before launch:

Erase/Clear track when you rig your kit or before each launch, otherwise old data gets mixed with new one.
Switch on your GPS shortly before launch.
Some scoring code considers a change of movement as your take-off time. So, if you move to another launch site while your GPS is switched on, the program will see this as a take-off. In case there is a major change in take-off area, clear your track log again.
Once landed , MARK your landing and switch off your GPS.
Have your GPS internal software up to date. You can download it from the suppliers web site.

For the GPS 12 download from the Garmin website http://www.garmin.com the latest GPS code which makes your batteries last longer. With the latest code, ordinary Alkaline batteries tend to last 12 hours in a GPS 12. Good enough for 3 days of flying?

One can use rechargeable NiMH or Alkaline batteries, which last in my GPS-12 for maximum 8 hours or 2 flights. But only with the latest GPS12 code. With the old code, the GPS 12 lasted only 4 hours or 1 flight on rechargeable batteries.
My experience on the newer GPS range with only 2 AA 1.5V batteries. Using 1.5 V rechargeable Alkaline batteries. And they seem to last not very long. Depends on the track sample rate. On a 1 second track log you get a battery warning after 1-2 hours. On a 7 second track log sample rate it goes flat after 4 hours. Buy batteries which got a 2000mAh capacity or more for those 2 AA GPS , like eMap, 72, 76,...

What Competition Organizers have to take care of

Start Tarps, Turnpoints and Goals have to be GPS coordinates assigned before a comp. Use averaging facility of the GPS to get an accurate value with an error of around 3 to 4 meters.
Organizers have to announce beforehand which cables and GPS devices are supported
Task can only be set with accurate GPS coordinates. No more measuring of coordinates out out of a map.
Organizers have to provide an upload facility for turnpoints into GPS waypoints at registration
Organizers to cater for enough COM Ports and cables in the evenings to process the pilots fast
If there are Goal marshals, have them take along a GPS to make sure goal line is at the exact position. And use GPS for goal time keeping.
If you still use Starttarp marshals, they also need a GPS to place the tarp at the correct position and sector and open or close it using GPS time
The meet director requires a GPS to open and close the window accurate

More info on how to improve or mess up your score , goto

What pilots need to know located at http://gpstp.sourceforge.net/htmldocs/4pilots.htm

Vario combined with GPS

The top of the range of Varios offers the possibility to link up with a GPS. This gives you the possibility to determine the wind strength and direction. The combination of the 2 instruments, along with a speed probe , will help you fly best glide. And if you can guess the average thermal strength of your next thermal most accurate you will outfly everyone else in a competition or get the furthest in a cross country flight. Top of the range combined GPS/Vario units can also give you an idea of the center of the thermal, the drift of the thermal, which way to change to core the thermal better.

What is the best GPS to get?

This section gets outdated very quickly.

Garmin range

Connected to a Vario or Logger

Make sure your Garmin is set to NMEA 4800 for the Interface.
On the GARMIN, locate the SETUP/Interface Option and switch it into NMEA 183.2 4800 baud rate.

GPS72, 76,...

Do not operate a 72,76,.. in battery save mode. You will loose satellite connections and miss out on track points.

In the newer GARMIN range one can also define the type of NMEA record that gets send.
Use the Menu button, Setup , Interface.
Change the Interface from Garmin or whatever to NMEA and below it states 4800.
Highlight the NMEA and then use the Menu button and you get a choice of the output format.
Higlight the Set NMEA Output.
Choose the XX.XXX' (3 digits) accuracy, and do not tick any boxes.
No need for any enabled sentences. (If you tick them you slow down the sample rate)

For your GPS use high capacity batteries. Like NiMH 2000mAh or better to last for for the total time of your flight.
Ordinary Alkaline rechargeables will last for maybe 3 hours.

One can assume that from 2004 onwards only GPS devices which can log at least 4000 track points with height data will be accepted in Category 1 events.
SAHPA competitions are Category 2 or 3, the existing GPS range will still be accepted in those events for many years.

Older GPS Model, GPS38, 40,... seem to loose satellites easy and create intermittent and interrupted tracks.

Prices (June 2002) start from approximately R2000 for basic eTrex , GPS 12 for R2200, .. and the top of the range Galileo goes two thirds of the price for a new Paraglider..

What I reckon an ideal GPS should provide for Hang Gliding and Paragliding. My personal impression and some feedback from other pilots:

Big track memory. But beware of total memory capability and how much memory of this can be used for a current track log.

Also check if saved tracks get compressed and loose track points.

Some GPS track memory sizes

GPS 38 below 1000 track points
eTrex around 1000
GPS12 1024, means 4 hours on a 15 second setting
GPS12 CX 2048
GPS 3 10 x 1900
eMap 10 x 2000

With eMap and eTrex when you save a current track to a saved track , track info gets lost. Download a current track to a PC to keep the full flight.

Possibility to change sample rate, to any second or distance value

the basic eTrex and eMap, only 1 per second , or every 5 seconds in battery save mode, means memory used up after 1.5 hours
GPS12 + CX , flexible sample rate
new eTrex range, like the Vista offers the possibility to influence sample rate by time or distance

Battery life, at least for 8 hours

GPS 38, not very long from what I hear
eMap around 14 hours
GPS 12 around 12 hours, with new code 16 hours?
eTrex up to 22 hours in battery save mode
GPS 12 CX up to 35 hours
GPS 3 got 36 hours

Readability of display and show the important info , like speed and distance

basic eTrex , I battle to find the right info for me on one screen
GPS 12 , could be better, especially with cover over it
GPS 12 CX , color display , claim to be better compared to GPS 12
eMap or GPS 3 seem to be good
eTrex Vista claim one can setup the display to show what you want

Ease of use while wearing gloves

eTrex , side mounted buttons, I find it difficult to manipulate them while flying
GPS 12 , front mounted buttons, still too small to press them while wearing gloves
eMap , difficult to use in flight, but Laura somehow manages
GPS 3 seems to be ok

If you are serious competition pilot who also attends overseas comps, get a plain GPS 12, the common standard.
Combined with a Log_It datalogger to give you a big track memory.
If you intend to fly long xcountries, get any GPS . If you want to break a world record, add a Log_It to increase your memory.

If you fly for fun in a competition the GPS 12 will do. Using any older models, like GPS 38 or 40 can frustrate your competition experience, with interrupted track logs and small memory.

Entering a competition with a low end eTrex or the eMap you are taking chances of loosing a lot of your track.

Check with manufacturers web site ( www.garmin.com) on latest specs and capabilities of their GPS.

The eTrex Vista is a good mix from a memory and sample rate point of view. A Vista pilot is creating long queues at scoring with their massive track logs.

The GPS 12 is at the moment still the international standard supported by all competitions.

GPS with Map displays is preferred by pilots who attempt to break world records in unfamiliar territory. It allows them to get an idea where they are.

But the eTrex range with Map displays I would rate as too small and clumsy to be used with gloves in the air

eMAP BRG and Distance

To get the BRG and Distance from a pilot or for recovery , one has to move the pointer arrow to the waypoint takeoff that you see as GOTO.
Then a tiny little line gets displayed, far too small for anyone who needs to see that info.

MLR - not sold anymore

Puts a track log the moment you enter the cylinder.
Switches to the next waypoint once you get into cylinder.
Got a 4000-8000 track point memory

Has problems somehow every time around bumpy peak where MLR pilots become time travellers.

Since it is outdated, and not supported anymore, unless you get it cheap, 2^nd hand, rather invest in some newer technology

LOG_It , MaxLogger, RobLog or other data loggers

Allows you to run in a 1 or 2 second track mode and store altitude info . If the interface is NMA based then with a GARMIN one gets every 2 seconds a trackpoint. Witha Magellan one can get a 1 second trackog. With a GARMIN using TEXT interface one can get a 1 second tracklog.

Top Navigator , Galileo, Flytec 5030,6030,Compeo,Compeo+

1 second track log, speed to fly, vario, points to strongest recent lift, recore, find lost thermal, makes a sound when you get into cylinder .

When you are very serious about XC and comp flying.

Competino, XC-Trainer, Flytec 5030,6030,Competino+

Scaled down units from the Galileo/Compeo and Top Navigator . Aimed for PG pilots. For those who are serious about PG XC or comp flying.

Trends

The DHV in Germany have started a country wide XC league Online Contest based on GPS generated IGC data. I use the Maxpunkte code to download my track, and optimize it. Then hand edit the OLC file country code from US to ZA before I submit my flight to the OLC. The next MaxPunkte release in 2005 should cater for ZA.

There is also a worldwide XC free flightinternational flight log web server where everyone can download their tracks at
http://www.kkpg.no/ which can be used by South Africa.
Maybe here in South Africa we also have one day a country wide XC league instead of a club based one?

Or use any of the other XC links, like

http://www.xcontest.org/world/en/

http://www.xccomp.org

http://wxc.fai.org/

http://www.paraglidingforum.com/modules.php?name=leonardo&op=list_flights

In 2007 the current GPS technology is in its early stage. And the methods and processes are in an experimental phase for Hang Gliding and Paragliding.
A plain GPS chipset costs around R800. We will see GPS combined into Cell phones over the next years. With an option to send an SMS of your current position. No more need to radio your position and clog up the airwaves. Assume in some years you can SMS off your current position in regular intervals while you fly.
And the moment you landed your track log can be SMS / emailed off straight out of your Cell Phone to the xc league database or competition scoring computer.

The rest of the flying world, like Sailplanes, Soaring Society, uses data loggers.
And one can buy dataloggers , like the Log_It, which connect to a GPS and act as a sort of big track memory.
Top of the range varios are now out which combine a GPS / VARIO / Datalogger device in one unit. Not cheap.

Over time there will be some common standard, probably based on the sailplane IGC format, in our flying world to store your track logs.

GPS Tips

Display faded away on GPS12 or eMap? Contrast Setting got pushed. Re-adjust the contrast. Left-Right arrows in Satellite Page

Buy yourself a protective cover. A cracked display is a finished GPS. There is no way of fixing a cracked GPS display.

If your GARMIN GPS 12 is screwed up ... try
> Press and hold the PAGE key;
> Switch the unit ON;
> Release the PAGE key (accept the 'search the sky' message given);
> Leave the unit to re-acquire the satellite data - for about 20 minutes.

> This forces the GPS to reload the satellite data, it does not effect any of your user data.

DO NOT LEAVE YOUR GARMIN GPS WITHOUT BATTERIES!

Keep your batteries in the GPS to keep the memory and Lithium battery alive.

The lithium battery draws a small charge from the alkalines to recharge.
When you leave the GPS without alkalines, the lithium can go flat (after a
few months). This means losing the data stored.

The lithium cannot be replaced in any GPS's except a GPS II Plus, III Plus
and Street pilot (or presumably any GPS looking like those). It is therefore
not possible to replace it in 12's and the other types.

If you have a new 12 (still under warranty), they will replace the unit. If it is no longer under warranty, then you might get about R400 off your next
purchase.

However, if your internal lithium battery has gone flat, then all may not be lost. Replace your alkalines and leave them for about 5 - 7 days. If it is not damaged or the unit is not damaged, then your lithium may get recharged, and your unit will function normally again.

Make sure that the alkalines that you leave in are not leaking, or cannot leak.

Batteries

Use high capacity batteries. Rechargeable alkalines used with a high track sample rate seem not to have the umph to last long enough.
Opt for NiMH with 2000 mAh or more for some hours of flying.

In 2009 use hybrid NiMH batteries for Competino, Flytech , if you want to go for rechargeable batteries. Do not use the plain NiMH, they discharge too fast.

But,.... the recharge times for a hybrid are looooong. If you managed to run it flat, no chance to have it recharged over night.

If you go hybrid, have mulitple battery sets, which you can rotate on a daily basis, when flying in a comp.

Time Difference between GPS , snippets off EuroPG

(Nearly) All about the time inside your GPS

The time that comes out of the NMEA port when the unit is locked on is
always UTC (even Garmin got this right otherwise they would have had
problems interfacing with other navigation equipment).

The time displayed on the screen is UTC (with the user set time zone
correction in whole hours) when the unit is locked on (otherwise it drifts
off slowly). However this may not be the time recorded on the track log. The
time recorded on the track log may be GPS time (currently 13 seconds later).

The time recorded in the track log should be UTC. However Garmin screwed up
and on some of their units the track log time stamps are in GPS time. It
could be only the Garmin units that have this error. GPS time has no
business escaping from inside the GPS onto the track log and it should never
have been there.

GPS time is for spacemen, Satellites, and the inside of GPSs. UTC is for us
earthlings (no matter how high the thermal goes). Because the earth doesn't
take exactly 24 hrs to rotate us earthlings agreed to average our clocks so
everywhere we go on earth we can use UTC and have it exactly the same.
However orbiting objects need to make precise calculations affected by the
earths rotation and therefore use GPS time.

Big Brains based in the USA keep the time used in orbit a whole number of
seconds offset from ground based UTC and decide only a month or so in
advance when they will take a second out or add a second on to the
difference between UTC and GPS time. The messages from the Satellite to the
GPS contain this offset data so all the GPSs on the ground can correct their
internal GPS time to UTC.

Now the offset between GPS time and UTC is quite a lot in terms of the
separation of gliders crossing a goal line in a hang gliding competition.
Currently 13 seconds.

You can see an illustration of the difference at:

http://www.leapsecond.com/java/gpsclock.htm

Note this displays the relative differences based on your PC clock and not
the true reference times.

Nobody realised that some GPS units have the wrong time on the track log
when they are flying at the start of the course even though they are
carefully timing their exit to the start circle or sector. This is because
their track log is correct or 13 seconds (at the moment) later. So when they
are timing their start to the 15 minute intervals they have to leave 13
seconds too early before they get clocked by 15 minutes. Setting off a few
seconds early doesn't help much so nobody realised this.

At the finish the checking programs do some maths to try an pin point when
the pilot crossed the line by using an average speed between track log
points, or projecting the average speed toward the line (or goal circle).
Finishing times didn't seem to be accurate but this was put down to the
unpredictable glide path beyond the line and the complicated sums in the
checking program. Recently though we realised something was wrong with the
track logs.

Christian Quest reports that Garmin are reluctant to come up with a list of
which units are affected.

The only mention of the leap second correction on Garmin's update page for
the common units (12, 12XL, 12Map) is this:

"GPS12MAP

Changes made from version 2.02 to 2.03:

Adjusted times recorded in track points by applying leap seconds."
Latest version is 2.05

I know that one day in Australia (at Denilequin using GPS goal circles) I
found I could get a score about 13 seconds better on my MLR GPS than with my
GPS12XL running version 3.53. (this is an early unit and this is the latest
software it can handle).

I suspect that all the "12" series have this problem except for the 12MAP
which definitely doesn't if running 2.03 or later and all these 12MAP units
can run 2.05.

One day at Denilequin I entered the goal circle simultaneously with two
pilots, at least one of whom was French and probably using an MLR. I was
recorded as arriving later than these two guys. This could have been the 13
seconds.

Maybe Christian Quest or Ivan Twose can come up with a way of reading the
track log times when we load the units with waypoints at the beginning of
the comp. At the moment the only way I can think of is by simulating a start
or finish by running the comp checking program on a number of GPSs that have
been driven round a course.

Maybe I'll do that if the weather stays like it is now! I could cover 12XL
2.53, 4.57 and another version on a 12 and compare that with the 12MAP on
2.05.

We could build up a database pretty quickly probably!

Conclusion
In regional competitions the results are seldom close enough to worry about
the effects of these 13 seconds. In the UK we used to use databack cameras
and round to the minute. GPS is a lot better than that!
In CAT2 and CAT1 internationals there is often a sprint finish and there are
a lot of points separating pilots who are less than 13 seconds apart. Until
we have a way of correcting for the leap minutes we must use a goal marshal
to correct the finishing order. We can use the GPS times as a guide and at
least we know that we should be able to get to the right times by adding or
subtracting 13 seconds!

If you have a GPS 12MAP make sure you are running software 2.05 and you know
you have the right time, (and make sure you don't cut the start too fine)
(same for MLR users). You might like to be sporting and ask for a correction
if you see pilots who were ahead of you scored as slower.

>>> from FAI IGC web site

GPS system time - is the continuous and highly accurate time kept by the GPS satellites. It began as UTC
for 6 Jan 1980 when the system first became operational, and maintains that time frame. It does not change
with the 'leap seconds' additions that are made to UTC to allow for the slowing down of the Earth's rotation
(see under UTC). In year 2000, UTC was 13 seconds later than GPS System Time. However, the GPS
system keeps track of leap seconds corrections, and these are sent as part of the satellite's message to users.
Most receivers use the GPS satellite message automatically to compensate and output UTC rather than GPS
time. In some GPS receivers, stored track records do not take leap seconds into account and output in GPS
system time, whereas NMEA data outputs generally include leap seconds and times are corrected to UTC.

MLR cable

This information copied from the manual page 10, Version 2.0
Looking at the connector you will find 3 plastic location notches.
Using the same numbering scheme as the manual, pin 3 is directly
between the 2 small notches. The other 4 pins are numbered clockwise.
Alternatively, if the GPS is held upright with the connector at the
top, Pin 1 is at 6 o'clock, 2 at 8, 3 at 10, 4 at 1 and 5 at 4.

Pin 1 is external antenna power supply output @ 2.7V. I wouldn't take
more than 50-100mA from here.

Pin 2 is DC input 10-20V

Pin 3 is NMEA / MLR data output

Pin 4 is NMEA / MLR data input

Pin 5 is Gnd (0V)

To wire your MLR to a PC DB9 serial port connect
MLR pin 3 to PC pin 2
MLR pin 4 to PC pin 3
MLR pin 5 to PC pin 5

Another good link is http://www.pdhcenter.com/courses/l116/l116.htm

GPS 13 seconds time difference http://www.flyaboveall.com/gps/

Where you can post your GPS tracks.

http://www.pgforum.com/modules.php?name=leonardo

with Landsat background picture

http://www.flightlog.org

old link
http://www.kkpg.no/index.php3?id=93&l=1

with a map background

http://www.kkpg.no/index.php3?id=93&l=1&a=21&country_id=193

lists the SA flying sites

http://www2.onlinecontest.org/holc/
popular with German pilots. With a DEM ( Digital elevation Model) based color background. 6 Euro entry fee to claim some of the prize money.

Got replace with http://xc.dhv.de/xc/modules/leonardo/index.php?name=leonardo&op=list_flights&season=2009

Other options

http://www.xcontest.org/world/en/

http://www.xccomp.org/module.php?id=1&date=20090816

http://wxc.fai.org/module.php?id=1&date=20090604

Tracking Options http://stpxml.sourceforge.net/skygod/Navigation/TrackCompare/

Fly, Crash, Survive http://stpxml.sourceforge.net/skygod/Navigation/fcs.html

The TP code http://gpstp.sourceforge.net/ and http://sourceforge.net/projects/gpstp/ for scoring tracks in a task

The T3D2 code http://t3d2.sourceforge.net at http://sourceforge.net/projects/gpstp/ for analyzing flights

This document is located at http://stpxml.sourceforge.net/skygod/Navigation/gpsinfo.html