[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: Multi Satellite pass predictions ?



>>> "Ronald Nutter" asked:

> When time permits, I like to work multiple passes from different 
> birds in the course of several hours.  Does anyone know of 
> software that will give me a printout of when the birds I want
> to work are within range and where they are ?

Yes!  See APRStk.

In addition to showing you a map going out 6000 miles from
your station so y ou can see any other APRS satellite users
it has a very valuable display across the bottom of the
screen.  It shows graphically all satellites expected in the
next 2 hours and their elevation angle.

See a sample display on this web page:

  http://www.ew.usna.edu/~bruninga/astars.html

Look 3/5ths of the way down the page at the USA  map.
But now look closely at he bottom of the map and you will see
a graphical representation of ALL amateur satellite passes 
over the next two hours.  Each yellow tick mark is 10 minutes.
You can see at the instant this graphic was taken, that there
were 9 difference satellite passes in just the next 80 minutes.

I developed this display for my casual use, becasue no other
satellite tracking software gave this big picture.  Now I have
it running all the time in my office and at home so that at any 
time I walk into the room, a 1 second glance at the screen
will let me konw what is coming up in the next 2 hours 
without even touching a thing.  And it runs on an old 386
laptop.

I find this display invaluable for casual use.  AND there is more.

If you hook a Kwnwood APRS radio to he serial port, it not
only tunes the radio to each satelite as it comes into view,
it also sets the internal TNC baud rate and Mode as in Mode
J or mode B or simplex or whatever.  This way, your PC
doenst miss any passses of anything in view.  If it is a packet
satellite, it captures a list of all users, and all UI packets.  If
it is an FM voice pass, then voices just start appearing on the 
speaker.  I want to add the Kenwood 2000 so I can hear
the analog birds, but I havent yet.

But there is more!  If you find that you dont hear but the high
elevation passes on your whip antenna (with short coax run) 
you can simpley connect a Radio Shack or any 24 AC TV 
rotator to two bits on the LPT1 parallel port via a $10 opto-
isolateor and two Triacs and the program will automatically
track your small beam to always point at the satelltie in view.
Its only a 2 wire interface...

See http://www.ew.usna.edu/~bruninga/rotator1.html

AND since it is only software, it also tunes the radio for
Doppler!

Now again, it is a DOS program, and I am not a modern 
programmer, but it is just something I wrote because no other
Amateur Tracking program gave me these simple features for
casual monitoring of anything that was in view.  Now I wrote 
this back in 1998, when there were 18 working Amateur 
Satellites and during an evening you were never more than a 
half hour from some pass of something...

These days, their ain't much up there.  Oh y es, the program
does one other thing not shown on the example above.
For that photo, I told the program I was interested in ALL
amateur satellties.  But for normal operation,  you only mark
the ones you can hear on the FM rig or that you are interested
in, and only those show up with a solid graphic hump.  The
others only show up as a thin outline.  THus from a glance 
across the room, if you see solid, you can work it.  Otherwise
the display is not cluttered by satellites you are not interested
in.

And LASTLY, I have not released a new version of this program 
in a few years, because I made a lot of changes and now the
source code just wont work.  ARGH!!!  I dont know if it is new 
PC's or what, but after spending weeks on it, I have given up.  Thus
the program has some improvements I would like to make, but
the only working copy is what is avaialble for download and it
is old...

I sure wish some really good programmers would take these
ideas and put them into their products.  I think one MAC
tracking program did take the graphic time line idea and
add it, but I havent seen it in any others..

I think you can still download APRStk from TAPR.ORG
from the SOFTWARE link under LATEST APRSDOS, but
you also have to download and install APRSdos first.
And you see that its just a not easy thing to quickly do... I just
wish I could get the source code fixed so I could update
it and make it stand-alone!.... alas...

But these days APRSdos no longer requires a validation 
number so if you have the inclination, just download the
latest APRSdos (I think it is APRS863.zip) and unzip
it into an APRS directory and then unzip ASTK-exe.zip
into the same directory and run APRStk.exe and it should
work.

Bob
de WB4APR
----
Sent via amsat-bb@amsat.org. Opinions expressed are those of the author.
Not an AMSAT member? Join now to support the amateur satellite program!
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home