GARETH MITCHELL: Well I think GPS is in the Wickipedia. In fact definitely is, 9 of us were having a rather unintentional experiment to put it to the test over the weekend. That’s GPS not the Wickipedia. Because there are group of LADS split into two cars driving into the middle of nowhere for some boyish fun with some hovercrafts. In my car we just had a map. The others had Sat-Nav. But close to the destination, the GPS just got completely confused and the Sat-Nav boys ended up following us a lot with a good old-fashioned map. So I couldn’t help wondering GPS can be improved. Well “Yes”, say the people behind EGNOS, which stands for European Geostationary Navigation Overlay Service. EGNOS is just on trial at the moment but ultimately it’s going to be a network of ground stations and geostationary satellites to augment the existing global positioning system boosting its navigational accuracy from around 15 meters to within 2 meters or possibly even better. Well the project aims to do the same for the GPS European counterpart — Galileo when it comes online. One of the people at the European Space Agency who have been involved with the trails of EGNOS is Dominick Ditan. He says it should be a big improvement on GPS.
加雷思•米切尔：我认为要找全球定位系统，可以去找维基百科全书。实际上，确切说，我们有9个人在周末随意对这个玩意进行了一项测试。当然测试是全球定位系统，而不是维基百科。因为我们这群人分成两组，分坐两辆车，目标却是男孩子们玩的气垫船。我开的车里，只有一张地图。其他人开的那辆车，却有卫星导航仪。但是在接近目标的地方，全球定位系统却完全迷路了，操作卫星导航仪的那群家伙，只好跟在拿着老式地图的我们后面，结束了这次征程。因此我有止不住的念头认为全球定位系统还很需要改进。“是的。”EGNOS（欧洲地球静止轨道卫星导航重叠服务）的推进者们给了肯定的回答。EGNOS目前还在测试阶段，但最终，它会成为由地面卫星接收站和同步卫星构成的网络系统，对现行的全球定位系统进行辅助，将使导航精确度从15米左右提升到2米以内，甚至更小范围。这项工程的目标是，一旦联网，EGNOS也能够支持欧洲全球定位系统副本——伽利略系统。欧洲航天局的多米尼克•迪坦已参与EGNOS工程。他说，这将是对GPS的巨大改进。

DOMINICK DITAN: The problem with the GPS is that this is a system that today you can not trust. Not because it is wrong or they want to fool you, but it’s because the best quality is for the military service which is only restricted to the military.
多米尼克•迪坦：全球定位系统问题是，当前它仍是一个不可信任的系统。这不是指它无法正确定位，或者随便糊弄你，而是因为最准确的全球定位系统只是为军事服务的，而且是仅限于军事服务。

GARETH MITCHELL: And you want to say basically augment the existing GPS service then. You’re saying it’s not trustworthy but you’re trying to make GPS for the time being anyway, make GPS more robust, is it?
加雷思•米切尔：您的意思是，主要是提高现有的全球定位系统的精确度。您先是说全球定位系统是不可信任的，但是您现在做的却又是改造全球定位系统，使其更可靠，是这样吗？

DOMINICK DITAN: We make it so as if you take an airplane the pilot let’s say is at an altitude of 100 meters going to Tula that he can be sure that he is at the altitude of 100 meters above the earth. And this is very important. You would…uhh…understand if you want to land the plane. Today when you use GPS if you take your hand receiver…before obtaining the data you have to push a button where you say that you use it at your own risk. It’s a liability issue and this liability issue won’t be necessary for EGNOS because we will send a signal which we have confidence in and if there is a problem we send out an alarm to the potential users.
多米尼克•迪坦：我们可以这样解释。如果你驾驶一架飞机要求飞行员在海拔100米进入图拉，那么飞行员就一定要确定在海拔100米。这点是很重要的。如果你要降落飞机，就会明白这点。而现在，当你使用全球定位系统，你拿着信号接收器……在你接受到数据之前，你需要按一下按钮，那么当你接受到了数据，却必须承担数据准确的风险问题。这也是一个关于可信任度的问题，但是对于使用EGNOS来说，这种可信任度的问题就不存在了，因为我们会确保发送信号的准确性，如果数据有问题，我们同样会以警告信息通知给可能正在使用数据的用户。

GARETH MITCHELL: And you’ve been trying all this, or haven’t you? in confidence?
加雷思•米切尔：你们一直在做这方面的试验吧，还是没有开始？确保准确性？

DOMINICK DITAN: Yeah! And there are many many tests that the idea is to certify it so that it will be part of the navigation system within the cockpit.
多米尼克•迪坦：是这样的。我们进行过许多这样的试验，为了验证它的准确性，以便将它纳入导航系统的一部分，装置于驾驶舱内。

GARETH MITCHELL: But as isn’t aviation, you know, if a pilot wants to know the height they have an altimeter and they calibrate the air pressure from air traffic control. Or they have beacon systems that they fly to, you know radio beacons and they’ve been doing that for decades and decades. Are they really ready to usher in a whole new way of navigating?
加雷思•米切尔：但是，就像在航空中，如你知道的那样，如果飞行员想知道高度，他们就会使用高度计（通过气压原理显示高度），按照空中交通管理的要求，来调整高度。或者是使用无线电塔系统，指示他们的飞行方向。而几十年、上百年以来，他们一直都是这么过来的。那么对于这全新的导航装置，他们是否已准备好接受使用了呢？

DOMINICK DITAN: Never, the idea is not to get rid of the existed which really works truly truly well. And if you combine both then you have the best system ever.
多米尼克•迪坦：不，不是这个意思，我们的想法并不是把现有的传统导航系统替换掉，因为这些传统的装置真的非常好用。而如果能把这新旧两套导航系统结合起来，那么才会是最好的系统。

GARETH MITCHELL: Yeah it’s always good to have a backup isn’t it?
加雷思•米切尔：是啊，有一个备用系统，总是好的，对吗？

DOMINICK DITAN: Yeah it’s a backup. For example we done those tests in Africa and we crossed Africa all the way from Senegal to Kenya that mean in the widest part of Africa using EGNOS not only to cruise but also to land. And there in Africa many many airports are not equipped with this ground facilities. So that mean that there is no other way and the satellite is a very interesting system.
多米尼克•迪坦：对，这是个备用的系统。举个例子，我们在非洲已做过这样的测验，我们从塞内加尔到肯尼亚一路穿过非洲大陆，这就是说，在广阔的非洲地带，EGNOS不仅可以用于巡航，而且还可以用于着陆。在非洲的许多机场还没有装置这样的地面系统设备。所以这就是说，没有别的方法，而卫星是一个非常有用的系统。

GARETH MITCHELL: And briefly, is there a consumer angle to all this? Are we going to have hand-held EGNOS devices for this greater accuracy as where walking around?
加雷思•米切尔：简单的说，这是消费者对所有这些的观点吗？当我们四处走动时，是否可以手持EGNOS设备就可以获得更精确的信息？

DOMINICK DITAN: EGNOS can be used in many many many other domains like tracking riders in Tour De France, or supporting or gauging the right persons. I mean this is really the first step for the application that we will later on developing in the full full scale with the Galileo navigation system.
多米尼克•迪坦：EGNOS 可应用于许多许多的领域，比如说在环法自由车赛中追踪骑手，支持精确定位某人。我所说的只是这种应用开发的第一步，将来我们会把伽利略航空系统应用到更加广泛的领域。

GARETH MITCHELL: That is Dominick Ditan.
加雷思•米切尔：以上是多米尼克•迪坦带给我们的访谈。