I came across this article today. It is an industry article about the next generation GPS receiver for the military. I’ll be honest here. I only used GPS a handful of times in the service and it wasn’t really much help to me. Like the article states, one of the critical things to know in a battle is “where am I?” I’m old school. I learned land navigation back in the days when land nav consisted of a map and a compass. I also had a solid grounding in the principals of navigation from my days in Sea Scouts, where I learned to use nautical charts, compasses and dead reckoning to determine my position.
During my time in basic training, I had classes in land navigation. I had to show I was able to identify on a map the five basic terrain features (hill, valley, ridge, saddle, deppression) and my understanding of contour lines and the marginal information on a map. I had to show my understanding of the military grid reference system (instead of using latitude and longitude, the Army overlays a grid over each map, much like the lines of city blocks). I had to show my mastery of such things as orienting the map and how to use a compass to determine an azimuth (that is, use the compass to determine the direction to or from a distant point). But the fact of the matter is, I rarely did any land navigation at all in my first assignment. I didn’t have to. I just had to maintain my position in my fire team. Even when I was the RTO for the platoon leader, he was the one with the map. I had my hands full just running the radio and maintaining the net. I’d be hard pressed to tell you where I was at any time during my first enlistment.
But when I became the track commander for an M-113 in Germany, I had to learn fast to keep track of where I was. My first couple of trips to the woods were somewhat frustrating. I never got lost, really, since the other vehicles of the platoon were usually nearby, but I just couldn’t break the code. I didn’t know where I was.
But my platoon sergeant hadn’t given up hope on me. He normally rode in my track. He gently coached me. One day, during an excercise, he reached forward to deliver a little more coaching. I said, “I got it” and I really did. The topographical map came alive in my hands. I could suddenly see how the lines that showed hills and ridges and valleys depicted the scene before me. I knew exactly where I was. And now I could not only see the terrain before my eyes, I could see the terrain beyond the next hill.
Once you can use a map to tell where you are, you can answer other questions as well, such as “they told me to go to point ‘X’, where the heck is that?” and “I just spotted some bad guys, how do I tell everyone else where they are?” Well, once you know where you are, you can use simple methods like terrain association to answer the questions: “I know the bad guys I spotted are on a hill to my west, and the map only shows one hill to my west” or “I know my destination is 5000 meters north of here and the map shows a saddle between two hills there. I’ll walk for about two hours until I reach a saddle between two hills.”
I reached a point where I was not only good at land navigation, I was VERY good. I served on the land navigation committee for the Expert Infantryman Badge Committee for two years at Ft. Carson. That wasn’t because I was good, it was because I was available. But we did have to lay out the waypoints for the land nav course. My boss, SSG James and I took the CO’s Humvee and some fence stakes and laid out the course. We had already plotted the points on the map. The issue was getting the stakes within 10 meters of where we had said they would be. I did it by eyeball. Just me and a map. I didn’t even take a compass. But we didn’t just trust my eyeballs. Once we had laid out the course, we went back and surveyed all the points with a GPS receiver. They were all in place. But that wasn’t good enough. We asked the kind folks in our supporting Field Artillery unit to survey the points with their high tech precision survey equipment. I had to move one point. I ended up moving it about 5 feet. Not bad for eyeballs and a map for 75 survey points. But time marches on. The GPS system was already in use and it would be a game changer. No longer would being good with a map be enough.
The GPS system is actually very simple. There are about 24 satellites in orbit around the earth. All they do is broadcast the time. But they broadcast the time very, very precisely. The GPS reciever carried by a soldier recieves these time hacks from several different satellites and compares them. Since it takes a finite amount of time for the radio signal to travel form the satellite to the reciever, the GPS will compare the difference between the time hacks of several satellites and determine how far away it is from them. A little trigonometry and geometery and poof, the reciever knows where it is. The cool thing is, the reciever doesn’t even need to know what time it is. Just the difference in time stamps from the satellites will tell it where it is. It is a totally passive system that can’t be detected. It is also very difficult to jam. And it is very accurate. It can tell you within 3 meters where you are just about any place on earth. Three meters may not seem pinpoint, but given that a Bradley is about 8 meters long, it’s close enough.
This instant ability to determine ones own location has thinned a fair amount of the fog of war. The Army’s current high tech battle management system is based on GPS technology. It is a simple matter for Bradley or Abrams to send a radio message telling headquarters where it is. And since it is tied into a computer, the graphics will show where all friendly vehicles are. A laser rangefinder now not only tells us how far away a target is, it tells us exactly where that target is. And transmits that message directly to the artillery or close air support that will attack it, often with GPS guided munitions.
GPS doesn’t solve all of a commander’s problems. But it does make much of the map reading tasks easier and less time consuming. That frees him up to concentrate on important things, like how to lead his team to victory.