1 00:00:00,000 --> 00:00:01,000 Hey, Shelly. 2 00:00:01,000 --> 00:00:02,000 Oh, hey, Van. 3 00:00:02,000 --> 00:00:03,000 Finally, I found you. 4 00:00:03,000 --> 00:00:04,000 What's going on? 5 00:00:04,000 --> 00:00:05,000 Oh, this is so neat. 6 00:00:05,000 --> 00:00:07,000 We're going to be in a road rally. 7 00:00:07,000 --> 00:00:08,000 A road race? 8 00:00:08,000 --> 00:00:09,000 That's awesome. 9 00:00:09,000 --> 00:00:10,000 No, no, no, no. 10 00:00:10,000 --> 00:00:12,000 This is not a race against time or speed. 11 00:00:12,000 --> 00:00:17,000 This is a race that's involved with how well we can navigate accurately. 12 00:00:17,000 --> 00:00:20,000 Something you probably could stand some help on, Van. 13 00:00:20,000 --> 00:00:22,000 Oh, hey, and this is Brad Ball. 14 00:00:22,000 --> 00:00:26,000 He's from the Geographic Information Team, and he's in charge of the road rally. 15 00:00:26,000 --> 00:00:27,000 Hey, guys. 16 00:00:27,000 --> 00:00:29,000 Shelly, Van, this is a special road rally. 17 00:00:29,000 --> 00:00:30,000 No maps allowed. 18 00:00:30,000 --> 00:00:31,000 We're only going to use GPS receivers. 19 00:00:31,000 --> 00:00:33,000 What's a GPS receiver? 20 00:00:33,000 --> 00:00:35,000 GPS stands for Global Positioning System. 21 00:00:35,000 --> 00:00:38,000 This little device, a GPS receiver, is the future of navigation. 22 00:00:38,000 --> 00:00:44,000 So just how does this GPS receiver work, and how are we supposed to use it in this road rally? 23 00:00:44,000 --> 00:00:48,000 The Global Positioning System is a constellation of 24 satellites that orbit the Earth. 24 00:00:48,000 --> 00:00:53,000 GPS makes it possible for people using ground receivers to determine their geographic location. 25 00:00:53,000 --> 00:00:57,000 By measuring the travel time of a signal transmitted from each satellite, 26 00:00:57,000 --> 00:01:00,000 a receiver can calculate its distance from the satellite. 27 00:01:00,000 --> 00:01:02,000 When receiving a signal from at least four satellites, 28 00:01:02,000 --> 00:01:07,000 a receiver can determine the latitude, longitude, altitude, and time. 29 00:01:07,000 --> 00:01:12,000 If the receiver is equipped with a computer that has a map, the position is shown on the map. 30 00:01:12,000 --> 00:01:17,000 If you are moving, a receiver may also tell you your speed, direction of travel, 31 00:01:17,000 --> 00:01:20,000 and estimated time of arrival at the destination. 32 00:01:20,000 --> 00:01:21,000 Oh, okay. 33 00:01:21,000 --> 00:01:24,000 I think I understand now how we're supposed to use this receiver in this rally. 34 00:01:24,000 --> 00:01:28,000 This receiver will help us navigate to each of our destination points, 35 00:01:28,000 --> 00:01:30,000 but we only have a certain amount of time to get there. 36 00:01:30,000 --> 00:01:32,000 Which means speed is important. 37 00:01:32,000 --> 00:01:34,000 So, I'm driving. 38 00:01:34,000 --> 00:01:36,000 Wrong, Van, on both points. 39 00:01:36,000 --> 00:01:38,000 In a rally, you maintain the posted speed limit. 40 00:01:38,000 --> 00:01:42,000 Using the posted speed limit, plus the distance to each checkpoint, 41 00:01:42,000 --> 00:01:44,000 we have calculated the time it should take you. 42 00:01:44,000 --> 00:01:47,000 Ah, time equals distance divided by speed. 43 00:01:47,000 --> 00:01:51,000 Right. Now program this receiver with your checkpoint coordinates. 44 00:01:51,000 --> 00:01:53,000 Your challenge is to find each point. 45 00:01:53,000 --> 00:01:57,000 The time and accuracy of finding each point contributes to your score. 46 00:01:57,000 --> 00:02:00,000 Shelly, you're the driver. Van, you're the navigator. 47 00:02:00,000 --> 00:02:01,000 Okay. 48 00:02:01,000 --> 00:02:03,000 One final rule. Here's your logbook. 49 00:02:03,000 --> 00:02:06,000 This must be signed and timestamped at each checkpoint. 50 00:02:06,000 --> 00:02:10,000 Also, at each checkpoint, you're to collect information on the navigation 51 00:02:10,000 --> 00:02:16,000 and how GPS applies to the featured site and get a clue to the next leg of your trip. 52 00:02:16,000 --> 00:02:19,000 Wait for the green light. I'll send each crew one minute apart. 53 00:02:19,000 --> 00:02:21,000 All right, Brad. I think we're ready. Okay. 54 00:02:22,000 --> 00:02:24,000 All right, all of us. How about hopping in? 55 00:02:24,000 --> 00:02:26,000 We've got room in the back. 56 00:02:26,000 --> 00:02:28,000 You can come along, help us collect the information, 57 00:02:28,000 --> 00:02:32,000 and maybe look over Van's shoulder. He'll probably need the help. 58 00:02:32,000 --> 00:02:33,000 Let's go. 59 00:02:42,000 --> 00:02:44,000 I still think you should let me drive. 60 00:02:44,000 --> 00:02:47,000 Hey, hey, hey. Navigate. You navigate. I drive.