# Doppler and direction calculation?

• Subject: [amsat-bb] Doppler and direction calculation?
• From: n3wwn@xxxxxxxxxxxx
• Date: Tue, 9 Jan 2007 18:10:35 -0500 (EST)

```
Hi!

I've been trying to find the answer to this question using Google, but
can't seem to find a complete answer.

How can I calculate the doppler shift and direction of travel of a
satellite accurately?

I have the following information based on the observation point:

Longitude
Latitude
Azimuth
Elevation
Range
Altitude
Velocity
Phase
Eclipse Depth
Squint Angle

For example (AO-27 - it's the first sat in my test keps):

Sat Lon = 82.58 W
Sat Lat = 27.10 S
Sat Az = 182.93
Sat El = -28.64
Sat Range = 7516.62 km
Sat Altitude = 799.74 km
Sat Velocity = 7.46 km/s
Sat Orbit Num = 69288
Sat Visibility = D
Sat Phase = 317.61
Sat Eclipse Depth = -62.93
Sat Squint = 360.00

I'd like to be be able to calculate the doppler for any satellite and any
frequency.

I'd also like to find out the direction of travel, relative to the
lat/lon coordinate system (90 if travelling east, 180 if south, 270 if
west, etc).

Can anyone help me out here with some equations or point me in the right
direction?!

Thanks!

73 de Rich N3WWN (FN00fh)

_______________________________________________
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author.
Not an AMSAT-NA member? Join now to support the amateur satellite program!
Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb

```

AMSAT Home