ccchhicago Posted July 11, 2005 Share Posted July 11, 2005 Do GPS's work around airports? I'm thinking maybe not because of homeland security. Quote Link to comment
+reveritt Posted July 11, 2005 Share Posted July 11, 2005 In my experience, the work just fine near airports. Quote Link to comment
+MtnRubi Posted July 11, 2005 Share Posted July 11, 2005 My GPS works great at both local airports, and both military bases around here Quote Link to comment
+webscouter. Posted July 11, 2005 Share Posted July 11, 2005 Most aircraft have GPS units in them. It would be a bad thing if they didn't work around the airport. Quote Link to comment
Toron Posted July 11, 2005 Share Posted July 11, 2005 I have heard of interference under the big power lines, but I have never heard of a device or system, other than the govt. scrambling the sattelite signals, that messes with gps reception. Is there such a thing? Other than that, I don't why a gps wouldn't work at at airport. Quote Link to comment
bogleman Posted July 11, 2005 Share Posted July 11, 2005 I work at a small airport and my GPS works quite well. There are no devices preventing a GPS from working in and around an airport. Pilots use GPS to help navigate. In an airport environment there are tons of radio frequencies in use that may cause interference (I doubt it though). If your GPS is not working or receiving a signal I would look for other possible problems such as low batteries or obstructions. DHS publishes several scenarios that possible unfriendly folks use and yes someone with a GPS acting suspicious, in and around an airport, could possibly fall into one of the scenarios. An airport is a very public environment and someone will be watching you and what you are doing if you are trying to be secretive about your actions or in an area that is sensitive/restricted to general the general public. Quote Link to comment
+Pork King Posted July 11, 2005 Share Posted July 11, 2005 I live near a training Air Force Base. At certain times of day, it is impossible to get a lock on the sats around this place. I have been told they scramble signals during take off/landing during these times of day. Quote Link to comment
+TresOkies Posted July 11, 2005 Share Posted July 11, 2005 I live near a training Air Force Base. At certain times of day, it is impossible to get a lock on the sats around this place. I have been told they scramble signals during take off/landing during these times of day. I've noticed the same result near Sheppard AFB in Wichita Falls, TX. I haven't noticed any particular problems at any of the dozens of commercial airports that I've traveled in and out of. Quote Link to comment
+Glenn Posted July 11, 2005 Share Posted July 11, 2005 (edited) I live near a training Air Force Base. At certain times of day, it is impossible to get a lock on the sats around this place. I have been told they scramble signals during take off/landing during these times of day. I've noticed the same result near Sheppard AFB in Wichita Falls, TX. I haven't noticed any particular problems at any of the dozens of commercial airports that I've traveled in and out of. Kind of reminds me of this story, Military radio signals could jam garage door openers. I don't think the military or a civilian airport would be intentionally or unintentionally jamming the frequencies that the GPS system uses because they are both users of the system. Edited to fix speling. Edited July 12, 2005 by Bushwhacked Glenn Quote Link to comment
+joe gremlin Posted July 11, 2005 Share Posted July 11, 2005 I live near a training Air Force Base. At certain times of day, it is impossible to get a lock on the sats around this place. I have been told they scramble signals during take off/landing during these times of day. Given that pilots can fly instrument approaches using GPS as their only guide (especially during training), I find this hard to believe. What good could it possibly do to enhance anyone's safety? Quote Link to comment
Dale_Lynn Posted July 11, 2005 Share Posted July 11, 2005 I live near a training Air Force Base. At certain times of day, it is impossible to get a lock on the sats around this place. I have been told they scramble signals during take off/landing during these times of day. Given that pilots can fly instrument approaches using GPS as their only guide (especially during training), I find this hard to believe. What good could it possibly do to enhance anyone's safety? Instrument approach to a airport is not GPS it is by radio beacon and radar.... GPS is primarily point to point navigation.... Airport to airport in this case... Dale Quote Link to comment
+IVxIV Posted July 11, 2005 Share Posted July 11, 2005 So bottom line.. does any sort of device exist that the military/government could use to locally BLOCK GPS's from working?? Yes they can tweak SA levels, but that's on a planetary scale, correct? Quote Link to comment
+beejay&esskay Posted July 11, 2005 Share Posted July 11, 2005 So bottom line.. does any sort of device exist that the military/government could use to locally BLOCK GPS's from working?? Yes they can tweak SA levels, but that's on a planetary scale, correct? I think they can (and have, for testing) messed with consumer GPS accuracy in certain areas. My understanding is that this is done at the "satellite" level...not by generating any interference locally. Quote Link to comment
+sbell111 Posted July 11, 2005 Share Posted July 11, 2005 (edited) Given that pilots can fly instrument approaches using GPS as their only guide (especially during training), I find this hard to believe. What good could it possibly do to enhance anyone's safety? Instrument approach to a airport is not GPS it is by radio beacon and radar.... GPS is primarily point to point navigation.... Airport to airport in this case... Dale This is a pre-WAAS answer. The FAA has since approved GPS approaches to many airports. Edited July 11, 2005 by sbell111 Quote Link to comment
Jeremy Posted July 11, 2005 Share Posted July 11, 2005 So bottom line.. does any sort of device exist that the military/government could use to locally BLOCK GPS's from working?? Yes they can tweak SA levels, but that's on a planetary scale, correct? Yes. There is equipment to jam GPS. Also there is "Selective Deniability" which allows some areas restricted access to GPS. This military advantage is why the European Union has been developing Galileo. Quote Link to comment
+Renegade Knight Posted July 11, 2005 Share Posted July 11, 2005 I've had trouble getting a lock through the large windows at airport terminals but great luck getting a lock through the dinky windows of the jets. I assumed it was either satellite constellation or they use a heat reflective film on the windows like some cars do. Those metallic films block signals though that's not their primary purpose. Quote Link to comment
+Joypa Posted July 11, 2005 Share Posted July 11, 2005 I ran in to this exact situation recently. The satellites were unstable, as if they would appear and wink out of existence. I figured it was some sort of scrambler effecting me. Needless to say, I could not get a fix. It was weird. Quote Link to comment
+Glenn Posted July 12, 2005 Share Posted July 12, 2005 So bottom line.. does any sort of device exist that the military/government could use to locally BLOCK GPS's from working?? Yes they can tweak SA levels, but that's on a planetary scale, correct? Yes, and do civilians, and so does other countries. Quote Link to comment
Jeremy Posted July 12, 2005 Share Posted July 12, 2005 Do GPS's work around airports? I'm thinking maybe not because of homeland security. Not when you forget to put the batteries in, silly. Quote Link to comment
+Team Cotati Posted July 12, 2005 Share Posted July 12, 2005 I've had trouble getting a lock through the large windows at airport terminals but great luck getting a lock through the dinky windows of the jets. I assumed it was either satellite constellation or they use a heat reflective film on the windows like some cars do. Those metallic films block signals though that's not their primary purpose. Would you say that that is their 'secondary' purpose? Quote Link to comment
+TheAlabamaRambler Posted July 12, 2005 Share Posted July 12, 2005 This whole using-GPS-approach to land aircraft scares the heck outa me - unless their GPS is one heck of a lot better than mine they'll miss the runway, or find it but way too soon, as often as not! My GPS showed me at 80' altitude the last time I was at the beach - standing at sea level! That bit of error could spoil a pilot's whole day. I use a GPS with the laptop and maps in my geomobile and it shows me driving 100' off in the woods or through folks houses beside the road on a daily basis! Glad I don't live near an airport! Quote Link to comment
+Joypa Posted July 12, 2005 Share Posted July 12, 2005 This whole using-GPS-approach to land aircraft scares the heck outa me - unless their GPS is one heck of a lot better than mine they'll miss the runway, or find it but way too soon, as often as not! My GPS showed me at 80' altitude the last time I was at the beach - standing at sea level! That bit of error could spoil a pilot's whole day. I use a GPS with the laptop and maps in my geomobile and it shows me driving 100' off in the woods or through folks houses beside the road on a daily basis! Glad I don't live near an airport! Apparently you have no knowledge of surveying technology. Relax, it's no problem with the right equipment. Quote Link to comment
+steve_c Posted July 12, 2005 Share Posted July 12, 2005 I thought the whole idea of trying to restrict GPS near aiports was so weird (what is the additional risk?), I decided to contact Gothenberg City Airport help email, to see what they said. (I will be travelling from there shortly, so the conversation was genuine (translated from Swedish): Me 11 july 2005, 14:23: Hi - I'm a big GPS-user (satellite navigation) and I wondered if you had the coordinates for the parking lot for Gothenberg City Airport [a small regional airport with one smallish lot] to make it easier for people like me to find the airport. Many thanks. Reply 11 july 2005, 14:32: The airport's registered position is 57:46,32 11:52,14. This is the centre of the runway, so there will be a certain inaccuracy, but I hope this will help you to find us. You can I suppose make a MOB-mark when you are parked. Have a good trip. --- Quote Link to comment
+sbell111 Posted July 12, 2005 Share Posted July 12, 2005 The coords to all airports are easy to come by. One would not need to go to the location to mark a waypoint. With my V, the airport coords are loaded automatically when I upload maps. Quote Link to comment
+joe gremlin Posted July 14, 2005 Share Posted July 14, 2005 (edited) Instrument approach to a airport is not GPS it is by radio beacon and radar.... GPS is primarily point to point navigation.... Airport to airport in this case... Dale So... You're an instrument rated pilot then? If so I think you might need an IPC before you launch into weather. This is a pre-WAAS answer. The FAA has since approved GPS approaches to many airports. Hmm... When I learned to fly instruments in the late 90's I flew many GPS instrument approaches. In those pre-WAAS days there were only non-precision GPS approaches meaning they had runway guidance but no vertical guidance. Vertical guidance is via waypoint passage only and therefore the descent minimums are higher than a true precision instrument approach but in my experience even back in the SA days GPS would fly you right to the runway every time I'll take a GPS approach over any other (i.e. ground-based) non-precision approach every time. The approach certified GPS units install in aircraft use a system called RAID (I can't remember what it stands for) that somehow predicts whether or not you'll have a good signal lock for the entire approach before you fly it. I don't know how it worked but a RAID light meant an immediate abort of the approach. Again given all this, scrambling the GPS signal is the last thing a pilot (or at least this pilot) would want at an airport. Sorry if I sound a little harsh here it's just a peeve of mine when people spread misinformation and pass it off as fact. Edit becuase I can fly but I kant spel. Edited July 14, 2005 by joe gremlin Quote Link to comment
+One of the Texas Vikings Posted July 14, 2005 Share Posted July 14, 2005 Yes. There is equipment to jam GPS. Also there is "Selective Deniability" which allows some areas restricted access to GPS. WOW!!!! So, that is why my GPSr doesn't work on the "grassy knoll" !! Quote Link to comment
PyroDave Posted July 14, 2005 Share Posted July 14, 2005 Man if there useing gps's for landings I hope theres are better then mine if not alot of planes will be landing on the grass about 70 ft or soo to the right of the landing strip. Quote Link to comment
+joe gremlin Posted July 14, 2005 Share Posted July 14, 2005 Actually they are better, the units installed in aircraft that are certified for instrument approaches are definately more sophisticated than the hand-held units we're used to. I'm not a technician so I don't know the specifics of all the differences but I know they are very accurate. They also cost from 20 to 100 times as much as the hand-held units we're used to. Keep in mind that GPS is not used to fly all the way to the runway. It's used to fly an approach to the runway in low visiblitly conditions meaning it lines you up with the runway and gets you close enough to see the runway visually. Landing is then done visually just like Wilber and Orville did it (only faster and with wheels). Also I'm sure no cares but since I was picking nits I'd be an a** if I didn't pick my own. Aviation GPS units use a system called RAIM not RAID as I said the other night. RAIM monitors the integrity of the signals recieved and gives an alarm if the signal integrity drops below a certain point. RAID OTOH is a redundant array of indepentant disks. I really shouldn't post while I'm studying for the A+ cert. Quote Link to comment
+Susieiz Posted July 16, 2005 Share Posted July 16, 2005 Related Question: Can you take your GPS through airport security? If yes, do you have to turn it on? Will they know what it is? Will it be damaged by xray? Can you use it in flight to add or edit waypoints? Quote Link to comment
bogleman Posted July 16, 2005 Share Posted July 16, 2005 for the previous poster No you dont have to turn it on, they may ask though. Yes they will know what it is, if not they will ask. No it will not be damaged (unless they drop it). Yes/No just listen to the pre flight guidelines. They being TSA Quote Link to comment
+TeamAO Posted July 16, 2005 Share Posted July 16, 2005 I wouldn't think there'd be any "scramblers" in the area, because Air Traffic Control needs to track these planes and they probably use GPS related equipment to do so. If it isn't working where your standing you may be in a highly magnetic field, because my digital compass goes on the fritz in these locales and it's impossible to navigate when you're spinning in circles according to it. The magnetic fields will also throw off satellite reception. But I highly doubt there'd be on in an airport. Quote Link to comment
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