The World for PSX
(Click on image for full-size version. More pretty screenshots available online)
PSX_Earth is an add-on (written in Java), which connects PSX to Google Earth (GE). It uses the Google Earth browser plugin (not Google Maps!), and it also communicates directly with the server built into PSX.
What you do not get:
What you do get;
[Obviously, a belly camera cannot look upwards (well, it could but would at best peer at the pilots'
bu seat of the pants; an important feature of aviating and aviators, but not so interesting as a view).
Therefore, for tilt angles above 0° = forward-horizontal, image delivery will switch over seamlessly to a "roof camera" situated in a small "astrodome", Lockheed Constellation style, with which the PSX planes have been equipped when Hardy wasn't looking.]
On the whole, GE has by now become so precise that it is quite possible to follow your flight right through the landing; you will find yourself touching down on the runway in GE, too. And you may very well be able (at least at major airports) to taxi around following visual cues, and even to be guided by signage if it is the kind they paint on the ground.
Tip: It appears that the GE plug-in is rather demanding in terms of performance; given the amount of work it has to do, this is not surprising. It might be a good idea to add it to a separate browser installation, so that your everyday workhorse browser is not burdened too much by the plug-in (unless of course you use it all the time, too, not just for PSX).
PSX_Earth.inifile, and edit as required:
PSX Preferences > Extras) that clients connect on the port given in your
java -jar psxEarth.jar
file://PSX_Earth2.html(e.g. by simply dragging the HTML file into your browser window).
Tip: Bookmarks are your friend. :-)
Click on the button currently labelled "Start!"
If all goes well again, you will see a text in green saying "PSX connected", which (as you have guessed :-)) means that the connection to PSX has successfully been established.
At the same time, GE will warp you to the current PSX location. This may take a while (and may carry you into space for a bit, see about "kangaroo hops" in Note 4), depending on how far from the initial location PSX is positioned.
Tip: While starting PSX_Earth, it is a good idea to put PSX in MOTION freeze mode, and to wait until GE has settled down at the PSX location and has transferred (and cached) all the map/image data needed here.
If PSX is moving at this time, nothing really bad will happen, but it may all take longer to settle down to some good-looking display.
Tip: Remember, though, that you also may have to fly the plane :-)
Tip: Obviously, this extra info causes extra performance load, so switch layers on and off as your "frame rate" permits or requires.
The PSX_Earth "BellyCam Control" window will stay on top of all other windows (even when it does not have the focus), so that you don't have to dig it out from behind the GE window every time you want to point the camera. You can however resize it if you prefer. And of course you can minimize it when not needed.
The sliders at the bottom and to the right will let you swivel the camera horizontally (bearing from 0° to 180° either way round), and vertically from -90° (straight down towards terra firma) through 0° (forward to horizon) to +90° (up to your zenith).
The slider to the left provides some zooming of sorts (see Note 2 to understand "of sorts"). Note that this scale is logarithmic.
Be advised that the airplane/"PSX" symbol you see when looking straight down is not your shadow. (It has nothing to do with the sun's position; besides, it's blue :-) It rather indicates your nadir, i.e. the point "directly below" you (i.e. the point where the line from you to the centre of the Earth intersects the ground... :-))
To help with positional awareness, a light-blue "needle" in the gauge always points to true North so that you don't have to do the math with your bearing and heading all the time (the GE "compass rose" also helps, but note that it references the camera = viewing heading, not the plane heading).
Example (see picture):
In an earlier discussion of PSX_Earth on the Aerowinx forum, we talked about also displaying routes and waypoints in PSX_Earth (a feature which the old PS1_Earth did include). At the time I promised to look into it, which I since have duly done. In fact, I had already started to implement this, but a crash of the development machine stalled these attempts (the crash causing the stall, whereas with aircraft, the stall causes the crash). The work may be continued but will take some indefinite time, so I thought it is better to release PSX_Earth already now "as is", and leave the route display for a later version.
Note that this feature is about display of the planned active route (as per FMC); the forum discussion originally referred to tracking the route as actually flown. Remember that you can also use the map on the PSX Instructor page
Situation > Position for these purposes.
A real zooming function would bring you (optically) closer to the point you are looking at; in GE this would require moving your actual position closer to the view target, which is not feasible for PSX_Earth *).
The PSX_Earth "zooming" cheats by simply changing your altitude. If you are looking straight down (camera tilt -90°), this works just fine and is in fact the same as real zooming. But for oblique view angles it does not: You'll find yourself lower, but not closer to the point you're looking at. This may or may not be useful.
However, if you need real zooming, you can always disconnect PSX and then zoom toward any target (or indeed freely move around), using the GE user interface. Then reconnect to PSX; if the aircraft position has changed in the meantime, GE will catch up with it automatically.
*) The problem is that GE knows only the "eye" (GE camera) position and altitude, which are affected by zoom and tilt.
But GE does not know about any other "real position" of the observer (or PSX aircraft), independent of the camera.
Try the following:
Therefore "zooming" in PSX_Earth means really only changing the camera altitude, without changing the lon/lat coordinates.
This subject is as dear to every flightsimmer's heart as it is tricky...
With PSX_Earth there are, for starters, different rates involved:
It is therefore impossible to state conclusively what "target frame rate" can be achieved; the outcome will be different for every user.
My impression is that an update frequency faster than perhaps 2 "fps" does not seem to be attainable, at least not with the current approach.
So, don't expect the fluidity (ha!) of true Flight Simulator scenery; better think of PSX_Earth as a rather fast and smooth "moving map"...
This note explains the purpose of the experimental "fly-to speed" slider — an explanation merely for the connoisseur: in normal usage it is perfectly safe to leave the slider simply where it is and entirely ignore this note...
As it turned out, the GE way of doing things has one rather quirky and (in this add-on author's opinion) unfortunate design feature:
When the user changes position, or clicks on a link connected to a GE location, GE will "fly to" the new position, i.e. an animated "voyage" to the new point will be displayed. The speed of this "fly-to" can be controlled via the API, from very slow to "teleport" speed (the latter means that the location change is instantly, without any interpolating animation). All very nice.
The problem is however that GE does not fly from point A to point B at a constant altitude (maintaining the "eye altitude") — for unknown reasons (eye candy show effect, probably), it always does a parabolic "high jump", kangaroo style, thus:
You are sitting at A with an eye altitude of 5 km, and then jump to B which is about 20 km away. You will end up at B at the same 5 km eye altitude again, as you should; but instead of moving along at 5 km altitude, during the jump ("fly to"), you'll be lifted up to a maximum altitude of about 450 km (!).
For general end-user usage of GE this may be a nice visual gimmick, but it's a pain in the neck for purposes such as PSX_Earth:
As discussed in Note 3, the coordinate updates will come in at a fast rate (1-2 Hz), which means the spatial distance between two position updates in GE is rather small (something like 200 m per update, at cruise speed). So, GE does not have much time and room for "high jumps" in between updates, but it still tries: Even if the resulting (unnecessary) eye candy altitude change is very small (only 0.1 km perhaps) it can still be clearly perceived.
The effect is a strange "pulsating" quality of the GE display, quite different from the "jerkiness" or stuttering all flight simulator users are only too familiar with.
This pulsating is most obvious when looking straight down towards the ground ("map view"); much less so when looking more or less forward ("out-of-cockpit view") towards the horizon.
Now, as said, the fly-to speed can be made user-controllable, and the obvious idea is to use a speed as high as possible (or indeed the "teleport speed" with no delay/animation at all between position updates). However, that involves a trade-off, unfortunately:
It is true indeed that the higher the fly-to speed, the less pronounced the "high jump" (and "pulsating display" effect) will be. But alas, at the same time the conventional "stuttering" or jerkiness of the movement increases: GE reaches the new position instantaneously or "too early", then has to stop more or less completely to wait for the next update from PSX_Earth, and then will move again very quickly.
At the other end of the scale, if the fly-to speed gets too low, the PSX symbol will actually run away, off the display: the PSX coordinate updates now come in too fast, so that the slowed-down GE interpolation can no longer keep up with them.
So, a compromise has to be found. In my setup, it is a fly-to speed of about "1" (the available range goes from "0" to "5"). But this may depend on many factors (see Note 3), many of which are user-equipment specific.
Hence the slider, so that you can try to find your own optimum, if you feel like experimenting.
Obviously, running this micro-webserver carries a certain risk of opening an undesirable door to the rest of the world.
Against unwelcome visitors, the server built into PSX_Earth therefore provides a few barriers.
You should understand these
1. in order to run the add-on properly, and
2. to assess yourself how big a risk may still remain (none of these "barriers" will be 100% water-proof).
Please note that security is your responsibility — PSX_Earth does not take any of it, make any promises, or give any guarantees in this respect! Do keep your firewall, ADSL modem/router, anti-virus software, etc. up to speed!
This is what has been done in PSX_Earth to keep things a little safer:
Even so, be careful. Carpe diem!
Or was it Cave canem?
Or Caveat emptor?
Latin, in any case. :-)
Thanks and credits go to
End of document
16.08.2014: version 1 for public release
© Martin Erdelen 2014