Ground Sphere CubeSat Ground Station

h1. Ground Sphere Operating Manual v0.2

{{toc}}

h2. Setup

Instructions on connecting the antenna, software defined radio dongle, and computer together to operate the ground station go here.  Note, be sure to talk about if the antenna should be mounted outside and if so, how.

h2. Hardware

There are two pieces of required hardware.  The antenna/receiver unit and a user provided laptop

h3. User provided laptop, minimum system requirements

* processor speed

* available storage

* graphics capability

* operating system

* open USB port

h3. To install the antenna/receiver

* plug the USB cable into the USB port

* Install the Zadig driver

To install the driver, follow the directions pertaining to Zadig here: http://rtlsdr.org/softwarewindows

h2. Software

There are two pieces of software needed to operate the ground station.  The satellite tracking software, GPredict, and the AX.25 decoder, SeeDeR.

gpredict is available at http://sourceforge.net/projects/gpredict/files/Gpredict/1.3/gpredict-win32-1.3-3.zip/download.  To install, unzip the downloaded zip file and follow the directions in the README.txt document in the unzipped file. 

h3. GPredict Operating Instructions

The user manual for gpredict is available at http://sourceforge.net/projects/gpredict/files/Gpredict/1.3/gpredict-user-manual-1.3.pdf/download.  Chapter 2 covers the basic operating instructions.

h3. SeeDeR Operating Instructions

* Ensure you have an RTL-SDR device drivers and the SeeDeR installed correctly via the [[Software Installation]] instructions.

* Launch SeeDer by running the *SeeDeR.exe* from the folder where you installed SeeDeR

* If the RTL-SDR device is detected, you should see a moving waterfall display

* You may wish to tune to an FM station to check basic performance:

** Type a typical FM frequency (say, 100,100,000) into the "Center" box.  

** Click in the waterfall display to hit the exact center of a station (or type the frequency into the "Frequency" box). 

** Select "WFM" under "Demodulation", and you should hear FM audio, and possibly see RDS data.

!http://opendesignengine.net/dmsf_files/414?download=!

* To pick up AX.25 data:

** Select "AX.25" under "Demodulation"

** Select the proper baud rate and modulation under "AX.25 Settings"

** Settings for SkyCube:

*** Uplink: 450 MHz, 9600 baud, 2FSK modulation

*** Downlink: 915 MHz, 57600 baud, BPSK modulation

*** Tweets: 915 MHz, 9600 baud, BPSK modulation

Extra notes:

* The sample rate under "Device Settings" can be left at the default 2.048 MS/s.  Higher settings do not increase performance, and have worse frequency response.

* If you have a high performance computer, select "Very High" for visualization quality.  

* You may have to play with the ACG and gain settings for proper reception, especially for local transmissions (at high power levels, the input data gets clipped unless the gain is lowered).

* Try clicking the edges of the waterfall window, as well as clicking and dragging.

* Bookmarks allow you to save most of the settings and quickly swap to them

* SeeDeR should work fine with more than one RTL-SDR device.  Settings are associated with a device, so you can see uplink and downlink data simultaneously.