Question Instrument Only Navigation Approach to Pad

[PaulG]

Hi. Is there an instrument only aid to precisely approach a landing pad?

I know the VOR/VTOL is fine for landing on the pad. I'm referring to the approach.

For example, if I'm at some altitude and distance from the base/pad, traveling at some velocity, the velocity vector cross hair can be aimed for that approach. But, is there an instrument system to do that same thing or is precise navigation via the HUD the only way?

Thanks.

 

[Tommy]

There is an Autopilot, but if you want to do it manually, then the HUD is your tool.
http://www.orbithangar.com/search_quick.php?text=baseland&submit.x=0&submit.y=0

 

[PaulG]

Thanks. Essentially, I want to do it manually.

The ReentryMFD comes closest as it shows the relative placement of the ship to the base on a long distance approach, but, it becomes less than reliable close range.

 

[Scattykat]

Your HSI MFD should help in addition to the VOR/VTOL MFD if the Nav Comm frequencies are properly setup

FYI: http://stoenworks.com/Tutorials/HSI, the complete.html

Hope this helps

 

[PaulG]

Thanks but the VOR/VTOL is most useful at close range. I'm looking for something to essentially guide me in from a distance without having to do it visually. I have been searching MFDs for a while and had come up with nothing; perhaps Tommy is right in that visual is the only way to go.

ETA: Aerobrake MFD is perfect, but can't be used where there is no atmosphere. Essentially, there is a mode that shows your projects landing point relative to your target. It would be wonderful if that would work on the moon (no atmosphere). So, I use a variety of other MFDs to do it.

 

[PaulG]

So, I figured I add a little information here for the archives, in case anyone in their forum search comes across this:

I found the combination of the BaseSync, ReEntry, and Surface MFD. But, more importantly is the way I now decelerate.

Before, I was turning 180° and using the main engines to slow down (retros don't have enough power if you want to slow down close to the base) and use the hover engines to control decent rate.

Now, I turn 90° up and only use the hover engines. By using the combination of altitude and its rate of change (surface mfd) and looking at the anticipated altitude from BaseSync, by using the amount of deceleration needed in ReEntry, and using the ship's angle to control forward and upward thrust, I found it much easier to fine tune the landing using instrument only approaches.

 

[PaulG]

Additional information to "solve" this post for future stumblers:

The new DVTools MFD does the job for landing on a pad with an "instrument only" approach. It will tell you exactly the horizontal and vertical dV needed to land.

 

[Cras]

I have used DVTools for this. It works very well.

However, my main method is to use Burn Time Calc and BaseSync. What I do is I try to mimic how Apollo did it. I wait until a little less than half way across the moon, then retro burn until base sync says I will pass something like 4 km above the base.

Then I level out and descend. I think use BurnTimeCalc and enter a manual dV that is just slightly higher than my current speed (and you may have to tinker a bit if you undershot, as you continue to gain speed as you descend) and set it for my retro engines, this will give me the distance I will travel applying that much dV. Then I plug in the frequencies for the VOR and the Pad into Comms 1 and 2, then watch until the VOR one comes alive, and when it shows me I am that much distance away that BurnTimeCalc predicts I will travel, I engage the retros, and slow down. Then open up the hover autopilot, and control the descent, start with something like -20m/s and then adjust. Then watch as you slow down. When getting close, I take full manual over the whole operation, drift over the pad, then use the autoland pilot, which essentially drops the ship and engine brakes right over the pad.

I prefer the BurnTimeCalc way myself, bu DVTools is an AMAZING add-on.

My primary vehicle is the XR-2 btw, but I just did the BurnTime method with the DGIV with great results. Gets me onto the pad every time and it is quite fuel effecient. DVTools method is probably more efficient, since you are burning retro at a higher altitude, so have less delta V and all you got to worry about then is applying the braking thrust properly, or lest you go from a powered descent to full on blunt lithobrake.