Duringthe PersianGulfWaragroupofAmericansoldiersscoopedup anew recruitatRijaid Airport, thendrovehim, withblackenedheadlights, directly across miles oftractless desertsand.Squintingtoward the horizon, hecould see almost nothing when suddenly the driver mashed on the brakes, gave him a quick salute, and instructed him to step out into the darkness. As his bootssankintothesand, hewasstunned torealizethathewasonlyafew feet away from the flap of his tent. Before setting out, the driver had keyed the tent'scoordinates into a Navstar receiver, so itcould guide him back again. No one knows exactly how many Navstar receivers ended up serving coalition forces along the Persian Gulf because mothers and fathers-and sweethearts, too-located a few stray units on the shelves of marinesupply houses/plunked down their money, and express mailed them to their loved ones in the Persian Gulf. A few resourceful soldiers called stateside suppliers long distance, then used their credit cards to order receivers, many of which arrived in Saudi Arabiaa dayortwolateraboardcommercialjetliners. Bythe timetheground war finally started, 4,000 to 7,000 Navstar receivers were clutched in the hands of grateful American soldiers. They were used to guide fuel-starved airplanes for linkups with aerial tankers, to pull in air strikes against enemy emplacements, to guide mess trucks toward hungry troops, and to vector Special Forcesunits intheir muffled dune buggies deep behindenemylines. Afew enterprising military engineers learned how to follow meandering goat trails so they could locate underground springs where the goats wa tered themselves. They then used their hand-held Navstar receivers to record the precise coordinates of each spring, thus insuring fresh water supplies for onrushing troops."

Two complete new chapters have been introduced. The first one, Chapter 16, amplifies the many rich interactions between Geographie Information Systems (GIS) and the Navstar CPS. The words and pietures in this new chapter foeus on the powerful eleetronie mapmaking techniques that rely on Navstar navigation together with the many benefits stemming from the full-eolored "layered" maps now being produeed. Chapter 17, which is also new, deals with Intelligent Vehicle Highway Systems (lVHS). Navstar navigation techniques form the hidden backbone of most of the new electronic teehnologies that are helping to make America's traffic f10w more smoothly. Chapter 17 c10ses with narrative descriptions of three interesting IVHS projects: emergency tow-truck dispatching, optimum ambulance-routing, and the in-car traffie reports now being beamed into family cars cruising along Ameriea's major traffic arteries. Many helpful individuals contributed toward the successful completion of Under- standing the Navstar. My lovely wife, Cyndy, was unquestionably the most beneficial contributor. Her affectionate comments and her broad-ranging support were greatly appreciated. So was her diligent and uncomplaining work in word-process- ing the many drafts of the final manuseript. The artists, Lloyd and lInka Wing and Anthony and Dianne Vega, were also enormously helpful in providing quality figures and tables on schedule. They have become true masters of the Macintosh computer with its many beils and whistles. Preparing a book for publication is a time-consuming, invigorating task. I hope you enjoy reading it as much as I enjoyed putting it together for your use.

Two complete new chapters have been introduced. The first one, Chapter 16, amplifies the many rich interactions between Geographie Information Systems (GIS) and the Navstar CPS. The words and pietures in this new chapter foeus on the powerful eleetronie mapmaking techniques that rely on Navstar navigation together with the many benefits stemming from the full-eolored "layered" maps now being produeed. Chapter 17, which is also new, deals with Intelligent Vehicle Highway Systems (lVHS). Navstar navigation techniques form the hidden backbone of most of the new electronic teehnologies that are helping to make America's traffic f10w more smoothly. Chapter 17 c10ses with narrative descriptions of three interesting IVHS projects: emergency tow-truck dispatching, optimum ambulance-routing, and the in-car traffie reports now being beamed into family cars cruising along Ameriea's major traffic arteries. Many helpful individuals contributed toward the successful completion of Under- standing the Navstar. My lovely wife, Cyndy, was unquestionably the most beneficial contributor. Her affectionate comments and her broad-ranging support were greatly appreciated. So was her diligent and uncomplaining work in word-process- ing the many drafts of the final manuseript. The artists, Lloyd and lInka Wing and Anthony and Dianne Vega, were also enormously helpful in providing quality figures and tables on schedule. They have become true masters of the Macintosh computer with its many beils and whistles. Preparing a book for publication is a time-consuming, invigorating task. I hope you enjoy reading it as much as I enjoyed putting it together for your use.

Duringthe PersianGulfWaragroupofAmericansoldiersscoopedup anew recruitatRijaid Airport, thendrovehim, withblackenedheadlights, directly across miles oftractless desertsand.Squintingtoward the horizon, hecould see almost nothing when suddenly the driver mashed on the brakes, gave him a quick salute, and instructed him to step out into the darkness. As his bootssankintothesand, hewasstunned torealizethathewasonlyafew feet away from the flap of his tent. Before setting out, the driver had keyed the tent'scoordinates into a Navstar receiver, so itcould guide him back again. No one knows exactly how many Navstar receivers ended up serving coalition forces along the Persian Gulf because mothers and fathers-and sweethearts, too-located a few stray units on the shelves of marinesupply houses/plunked down their money, and express mailed them to their loved ones in the Persian Gulf. A few resourceful soldiers called stateside suppliers long distance, then used their credit cards to order receivers, many of which arrived in Saudi Arabiaa dayortwolateraboardcommercialjetliners. Bythe timetheground war finally started, 4,000 to 7,000 Navstar receivers were clutched in the hands of grateful American soldiers. They were used to guide fuel-starved airplanes for linkups with aerial tankers, to pull in air strikes against enemy emplacements, to guide mess trucks toward hungry troops, and to vector Special Forcesunits intheir muffled dune buggies deep behindenemylines. Afew enterprising military engineers learned how to follow meandering goat trails so they could locate underground springs where the goats wa tered themselves. They then used their hand-held Navstar receivers to record the precise coordinates of each spring, thus insuring fresh water supplies for onrushing troops."