The Orchid Grower
A Juvenile Science Adventure Novel
The Orchid Grower
A Juvenile Science Adventure Novel about Orchids and Genetic Engineering
How GPS Works*
... “We can follow him around today and see what he does,” Dina suggested.
“Good idea,” Joab agreed, “but we have a little problem.”
“What kind of problem, Joby?”
“It’s almost eight o’clock and if the burglary takes place around midnight and we have to follow him to his hiding place, it’ll be very, very late before we get home, and…Mom and Dad, you know.”
“Then what are we going to do?” Dina asked.
“Nowadays, detective work is not like it used to be,” Joab stated. “We can follow suspects with the help of the computer and other electronic devices, what we in the police game call electronic surveillance.”
“I don’t understand a word you’re saying.”
“We can stay at home and still tail somebody.”
“How on earth do you do that?”
“Well, if you’re at the police station, for instance, in order to know exactly where somebody is in town all you need to know are two things—his direction in relation to the police station and his distance from the police station.”
“The computer screen at the police station can show the suspect’s direction in relation to the police station in degrees and his distance in meters. If you have a ruler, a protractor and a map of the town your job is done. You can follow his movements minute by minute.”
“And that’s not all,” Joab went on, pleased with himself, “you may not even need a map, a ruler, or a protractor at all, because the computer can do the work for you.”
“I don’t get it.”
“You see,” Joab went on, full of his own importance, “if the map of Dimona, with all its streets and addresses, is stored in a computer program, the screen shows the suspect’s exact location all the time. In short, the computer does the calculations.”
“And without leaving home,” Dina said, understanding.
“There’s more!” Joab went on, “We can have lots of other details about the criminal’s movements on the screen, too, like his speed and so on.”
“Like they locate stolen cars, Joby?”
“Then why don’t we start following Mr. Jacob right away?”
Joab glanced at his watch. “We have a lot of problems to solve before we begin.”
“Like…like …look, in order to do it we first have to plant a little radio transmitter-receiver—the tracking device—on Mr Jacob.”
“What’s a radio trans…trans…what are you talking about?”
“A radio transmitter-receiver—a TR—sends out radio waves—the transmitter—and can also receive them—the receiver, see?”
“But why do we have to plant it on him, Joby?”
“So the computer can calculate his direction and distance in relation to the police station.”
“I still don’t understand.”
“Look, the TR sends out radio waves. At the police station there’s a rotating antenna that keeps turning till it finds the direction the radio waves are coming from. Then we have the direction, okay?”
“Okay, now after the antenna has identified the location of the TR, it sends out radio waves to the TR. The TR receives them and without delay sends a signal back. Because we know the exact speed of radio waves and we can also measure the time it takes for them to travel from the police station to the TR and back, then it’s easy to calculate the distance?”
“Of course, it works like radar or like the way bats find their way in a dark cave.”
“You’ve got it.”
“But we still have to attach the TR to Mr. Jacob’s clothes,” Dina heaved a sigh.
“Any ideas how to do that, Din?”
“Maybe to his car?”
“A good idea,” Joab agreed, “but what if he parks far away from the crime scene? And he has also a bicycle—I’ve seen him riding it. He could even go on foot. Dimona is a little town, you know.”
“So, what are we going to do. Joby?”
Joab patted Blacky’s back.
“I don’t understand.”
Joab patted Blacky’s back harder, raising clouds of dust. Blacky moved away, annoyed, and lay down by Dina’s left leg.
“Don’t tell me,” Dina exclaimed hesitantly, “that you want to send Blacky to tail Mr. Jacob.”
“Give me one good reason why not,” Joab said decisively.
“As a matter of fact, I can’t.” Dina caressed Blacky’s nose, and he licked her fingers with pleasure. “I’m sure he’ll do a good job. So, we attach the TR to Blacky’s collar and send him after Mr. Jacob, right?”
“Yes, but…but we still have a problem.”
“What’s that, Joby?”
“We don’t have a TR,” Joab confessed.
“So how do we get one?” ...
* Interestingly, the author introduced independently the concept of the GPS, alongside a simplified technical explanation, since at the time the book was published (2003) he was not aware of the invention. In the book "GPS" is not mentioned and it is described as an electronic surveillance system using a dog collar tracking monitor and it is also suggested as a possible method for recovering stolen cars. (see Chapters 18, 19).
* This is an excerpt from The Orchid Grower - A juvenile science adventure novel about orchids and genetic engineering.