Radar Screen in Mountainous Terrain

[NOWAKE]

Hi There,
I fly for a 121 carrier and I was coming out of GJT eastbound at night using runway 11 and DEN was giving us radar vectors soon after takeoff.

(We got radar vectors inbound on the north side of GJT with a vector to a left base over a ridge the night before to runway 11.)

Our EGPWS was covered in red on both sides as we were vectored through a canyon on our climb out. Terrain peaks above 11,000 ft..

I have seen the round black radar screens in low country back in the day when we could visit you guys.

It occurred to me that I have never seen a radar screen in an area with mountains.

Could anyone post a picture of a radar screen that I can read that shows me what you guys see in mountainous terrain?? I would like to download the picture if that is possible.

I can't express my gratitude to all of you for the help you have given us over the years.

nowake

[Shyu]

It looks mostly like the green screens, The radars have MTI system so it'll take out most of the stuff that isn't moving. But there will still be stuff that is there as long as the radar is getting through and you are moving :-)

[NOWAKE]

Hi Shy,

Thank you for your reply. If you take a look at GJT, there is a canyon to the east there about 4 miles wide that DEN was vectoring us through.

If their radar does not have contours on it, how do they keep us clear of the terrain?

I do not know what a MTI system is. But my approach charts states that DEN can not provide safe altitude warnings below 14,000 ft. within 35 nm of JNC vor.

Can you help me with this? Can you guys see the mountains on your screen?

thanks nowake

[barty]

For a given area, there is a Minimum Vectoring Altitude, or MVA. You'll never hear a controller assign an altitude lower than that value unless they're clearing someone for a published approach procedure that stipulates a lower altitude as part of the procedure, even then, it will be conditional upon crossing a certain fix or when established on a radial or localizer.

Scopes do have symbols for obstructions, including some prominent terrain, but usually terrain avoidance is provided for in the MVA.

[NOWAKE]

Hi Barty,

Thanks, I figured they had to be able to see something on there. I am sure you know that MVA's are not published on our charts, we have MSA's. I believe MSA's are higher than MVA's. They probably have some kind of altitutde out there below which they can't see. A picture would be worth a thousand words though.

Let me know if you can get me one if its not prohibited. thanks

nowake

[barty]

Originally Posted by NOWAKE

Hi Barty,

Thanks, I figured they had to be able to see something on there. I am sure you know that MVA's are not published on our charts, we have MSA's. I believe MSA's are higher than MVA's. They probably have some kind of altitutde out there below which they can't see. A picture would be worth a thousand words though.

Let me know if you can get me one if its not prohibited. thanks

nowake

Well, I can't help ya out there...I'm not working for the FAA quite yet. I have seen one of the airspace maps before on a recent facility visit, which has the MVAs depicted on it. I am not certain if that is depicted on the scopes or not, the ones I saw (ARTS-III and DSR) did not have it displayed, but that doesn't mean it isn't available at the press of a button.