1. Field of Invention
This invention relates to golf and more specifically, to three-dimensional (3-D) mapping, photogrammetry, and light detection and ranging (LIDAR) techniques used to produce the software and data required for implementation into a series of golf course navigation software and physical hardware devices that use satellite navigation and geospatial database systems for assisting golf players, fans, and viewers in course navigation, visualization, management, and administration.
2. Description of Related Art
Golf is a game of accuracy, precision and distance. Without an expert caddie along, there's a lot of analysis and sometimes guesswork involved in determining shot distance to the hole, and various course targets such as greens or landing areas with water hazards in play. A golfer's club selection directly depends on the perceived distance of the desired shot.
Global Navigation Satellite Systems (GNSS) is a standard generic term for satellite navigation systems that provide autonomous geo-spatial positioning with global coverage. GNSS allows small electronic receivers to determine their location (longitude, latitude, and altitude) to within several meters using time signals transmitted along a line-of-sight by radio from satellites. Receivers calculate the precise time as well as position, which can be used as a reference for distance measurements. Within the United States, the NAVSTAR global positioning system (GPS) is the only fully operational GNSS. GPS is currently the world's most utilized satellite navigation system. GPS technology has made its way into devices designed to be used as a navigation aid by a player on a golf course. The primary goal of a golf course navigation system is to provide players with distances to all kind of features on the course and especially to the green they are targeting. Beyond basic distance-to-the-hole data, many standard, golf GPS devices tell you the length of your last shot; distance to, and location of targets and hazards; and distance to the front, middle, and back of the green.
Conventional golf GPS devices suffer from a number of drawbacks. First, the geospatial data used (satellite imagery and differential GPS collection systems) in the production in commercially available golf GPS devices, such as those produced by GPS Industries, Sky Golf's Sky Caddie, and Callaway's uPro is very low resolution and is no better than five (5) to thirty (30) yards or meters. This degree of error is critical as a player's full shot distance typically varies by 10 yards or more for each golf club. For example, a player may hit an 8-iron 150 yards and a 7-iron 160 yards. If the golf GPS device indicates that the remaining distance to a pin is 150 yards when it is really 160 yards, then a player hitting an 8-iron instead of a 7-iron will come up well short—an unnecessary error that may result in the player's ball coming to rest in a hazard rather than on the green. This type of inherent error is not well suited for a game considered by many to be a game of inches.
The accuracy of conventional GPS devices is further complicated as some courses are better fit to use the capabilities of GPS than others. For example, in order to obtain a location reading, the GPS receiver must have a non-obstructed view of the sky. Accordingly, courses with lots of trees and other types of natural obstructions are less suitable for golf GPS devices. Objects such a mountains or buildings between the satellite and the receiver can produce significant error, sometimes up to 30 meters.
The graphics displayed on conventional GPS devices are rudimentary at best. Some devices are very basic as they merely display distance data without illustrating respective hole layout, e.g., a superimposed graphic displaying the overall geometry of the fairway, green, and related hazards. Other devices may show a hole's layout, but only through an artist's rendering in two-dimensions using computer generated imagery (CGI). These CGI renderings are then referenced geospatially with latitude and longitude values. For example, the artist will attribute the CGI created bunker with a lat/long value. When this data is loaded to a device with a GPS receiver, the GPS receiver will try to record a true location relating it to the pre-rendered imagery. Recently, airborne imagery of an “oblique” hole layout has been implemented in a golf GPS device provided by Callaway. However, this oblique imagery and perspective view was acquired by Pictometry's Oblique camera system and is not considered a mapping or calibrated camera system usable for mapping or civil engineering. Moreover, all of the images used in these systems are acquired using non-stereo specifications and are considered only two-dimensional in nature, i.e., the hole layout is only displayed as a flat two-dimensional image. No stereo compiled topographic or 3-D terrain data (x,y,z) are provided with respect to changes in topographic elevation, height, and related information such as slope. For a game that depends on where and the way a golf ball lands and bounces, conventional golf GPS systems are woefully inadequate. For example, any device that does not calculate the change in hypotenuse or change in elevation (topography) between point A and point B, is programmatically assuming that a golf course is flat and that a constant horizontal grid of X and Y values are sufficient. In fact, this is not the case as golf courses are not flat and a “true” golf course navigation device must calculate for the change in hypotenuse or change in elevation, topography or slope with respect to a calculated distance between point A and point B.