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Help with distance detection question — Parallax Forums

Help with distance detection question

oliveralanoliveralan Posts: 1
edited 2013-11-21 07:19 in General Discussion
Apologies for my ignorance regarding this question. I was hoping an expert might be able to assist.

I'm working on a project in Stockholm to develop an alternative solution to GPS on a golf course. We're currently trying to find a suitable technology but at present we don't have one that ticks all the boxes.


Ultimately, we're looking for a product that can inform a player how far away he or she is (exactly) from the hole. Is it possible to have a transmitter located in the hole (or in the flag stick) which communicates a signal to a hand held receiver stating the distance between the devices?



I would be forever grateful if anyone could suggested a technology that might be able to support this solution. Thank you for your time.

Comments

  • vanmunchvanmunch Posts: 568
    edited 2013-11-19 10:19
    Just out of curiosity, why not GPS? Is it not accurate enough?
  • Hal AlbachHal Albach Posts: 747
    edited 2013-11-19 13:03
    This is just one person's opinion...
    I'm not all that sure that knowing the exact distance from any random location to the hole is all that beneficial. I don't know of any golfer that can place his/her single shot that precisely. Given enough mulligans he/she can get close, but a single attempt is just as much luck as skill. (Is the grass wet or dry, how hard is the wind blowing, is the ball sitting high in the grass or barely visible? These factors and many others, along with distance, will determine how well the shot is made.) Like many other golfers, I play so that my fairway shot towards the green leaves me about one hundred yards, where my pitching wedge will put me on the green (sometimes). There are enough markings along the way to give me a good idea about how far I am away, such as a red stake which tells me 100 yards to the green center or a white pole in the center of the fairway (150 yards), and many sprinkler heads are engraved with yards to center.
    On the green itself a whole new set of factors come into play, flat or hilly, which way is the grass growing, how long ago was it cut, wind (again), and how much money is riding on the putt. :innocent:
    Now, I do have an optical range finder that I look through where I place a line at the bottom of the reticle at the base of the flag and the top of the flag gives me the distance from a scale on the side of the reticle. I have not used it in years. I also have a SkyCaddie which I do use but the information it gives me is far more accurate than my ability to place any single shot that precisely.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2013-11-19 17:44
    Going with GPS (most everything else will be very expensive), you don't need transmitters in each hole. The holes don't move, and you can pre-map them using a good handheld GPS unit.

    You could use differential GPS for improved accuracy. These involve additional GPS transceivers mounted on the ground, at strategic locations around your course. You need compatible receivers carried by the golfers.

    Other methods of rangefinding require line-of-sight, which ignore the possibility that any particular shot may not be practical in one stroke. You want distances to more than just the hole, but arbitrary points where you need the ball to land. Hal makes the point well.

    Basically, this is a SkyCaddie. I have no idea what patents cover it, but if you're developing something for a commercial course, you'd want to investigate that.
  • max72max72 Posts: 1,155
    edited 2013-11-19 21:47
    Gordon, holes move around the green, for what I know.
    So a gps mapping would require recording the hole position every time the holes is repositioned.
    Nothing unsolvable. It looks like skycaddie has the option to update the pin position, probably from a preset list.
    It is not a dgps, so you have a couple of meters of error with waas or egnos enabled.
    Dgps would require more expensive receivers. Some handeld allow for differential correction using internet connection and a server.
    Don't think there are other sensors offering the same performance with the same range.
    I'm not a golf player but I did some dgps surveys on golf courses (cm accuracy), so I'm wondering if combinjng such a survey with mark positioning along the course would work. Let's say you place marks (from beginning of the green or anything else) on the edge of the fairway every 10 or 25 meters. Then you combine it with a green map. Would it work?
  • jmgjmg Posts: 15,173
    edited 2013-11-19 22:25
    oliveralan wrote: »
    Ultimately, we're looking for a product that can inform a player how far away he or she is (exactly) from the hole. Is it possible to have a transmitter located in the hole (or in the flag stick) which communicates a signal to a hand held receiver stating the distance between the devices?

    Candidates like laser-rangers or radar, will likely fail because a flag is not always line of sight, and can also be removed some of the time.
    Fixed reflectors at the sides, can solve some issues, but still leave damage / removal, or deliberate shifting.

    You could manage your own differential GPS, with a GPS unit at the cup, and a local RF transmitter (solar powered?)
    (Waterproofing and antenna angles aside)

    The golfer carries a RF receiver + GPS and compares their XYZ with the cup XYZ of the same time stamp.

    It needs 18 transmitters, at a minimum. Advantage is you gain precision and auto-sense day to day pin movements.

    I guess you could add transceivers to all Golfer-groups, if you wanted to know exactly where every group was.
  • prof_brainoprof_braino Posts: 4,313
    edited 2013-11-20 05:19
    If line of sight is available, there is a new high quality laser range finder unit for a relatively low price. The SR02 is going to be about $320 in US, you can order it directly from South Africa for $250 but the shipping is extra.

    http://www.lightware.co.za/index.php/lib-docs

    Stock, it measure 40 meters +/- 2cm in full sunlight. Range can be increased with optics and software settings.
    This is pro surveyor quality system, versus the equally expensive cheap golf range finders, which claim 40 meters +/- 1 meter
  • Mark_TMark_T Posts: 1,981
    edited 2013-11-20 05:36
    Differential GPS just needs one reference base station I thought - just to correct for atmospheric variation in that general area.

    But to get the maximum accuracy diffGPS can give requires special antennas at both stations which may not be practical.
  • max72max72 Posts: 1,155
    edited 2013-11-20 07:44
    A fixed base is enough for DGPS. Special antennas are required for cm precision. But from the base the receiver must send correction data to the rovers, and the rovers must be able to check correction data and compare them with raw satellite data.
    The GPS receivers are the special parts.
    Massimo
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2013-11-20 08:04
    prof_braino wrote: »
    If line of sight is available, there is a new high quality laser range finder unit for a relatively low price. The SR02 is going to be about $320 in US, you can order it directly from South Africa for $250 but the shipping is extra.

    http://www.lightware.co.za/index.php/lib-docs

    Stock, it measure 40 meters +/- 2cm in full sunlight. Range can be increased with optics and software settings.
    This is pro surveyor quality system, versus the equally expensive cheap golf range finders, which claim 40 meters +/- 1 meter

    Dog-legged holes would not really work with a line of sight concept, but you really don't always want distance to pin... you might want distance to points along the fairway where you can get a straight shot to the pin.

    It seems that a laser range finder or a GPS scheme are really the only to alternatives... unless you can get Tiger Woods to caddy for you. (Actually, a pro-caddy seems to know all this stuff, so may TIger Wood's caddy would be even better.)
  • Heater.Heater. Posts: 21,230
    edited 2013-11-20 08:19
    I love this idea. Get the distance measurements sorted. Then the angles, winds, and other variables. Then build a machine to play the game for you.

    This might actually make golf bearable:)
  • vanmunchvanmunch Posts: 568
    edited 2013-11-20 16:46
    You could do a smart phone app
  • Hal AlbachHal Albach Posts: 747
    edited 2013-11-20 17:42
    RA & USGA have jointly released a regulations update regarding Distance Measuring Devices. In summary, a DMD (or DME) can be used during play provided that a Local Rule is in effect allowing such devices, and providing that the device is only capable of measuring distance. If the device also has the ability to measure wind, slope, or humidity, even if those functions are turned off, the device is not permitted. A smartphone that has a built-in compass is also not allowed. Also, RA & USGA rules override Local Rules during an event such as the US Open, where players are not allowed to use any measuring device.
  • prof_brainoprof_braino Posts: 4,313
    edited 2013-11-21 07:19
    Smart phone app seems like a great idea. The phone itself can already do most of the parts, including the user interface and google maps satelite photo integration. The only remaining steps would be identify which sensors are lacking (E.G. laser range finder) and write the app that integrates all the parts.

    I imagine only pro golfers would be limited from using the tool, and even them only during tournements. Anybody can use anything during practice, no? And such a device would be useful in other application besides golfing. For example surveying a meadow for frisbee golf, etc.
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