Communications
Thanks to the kind generosity of Inmarsat, Lorenzo is using some impressive,
leading-edge equipment to send voice messages and photos back to us in KMi.
Thrane & Thrane Explorer 500 BGAN terminal
This high-speed device basically provides a connection to the Internet via satellite. Its the same system that the worlds' media use to send reports, photos, etc. from remote locations like Afganistan.
Inmarsat currently has two geo-stationary satellites providing coverage that spans Europe, all of South and most of North America, all of Africa, the Middle East, Central and South Asia. Irian Jaya is on the edge of Inmarsat's coverage of Australasia, but another satellite is due to be launched shortly that will expand their coverage to most of the globe.
To record his blog, Lorenzo dials in to a dedicated phone line to KMi connected to a Creative Labs voice modem card in a PC running
IVM's Answering Attendant software. This records the incoming message as a WAVe file, which is then compressed to an MP3 file using
Audio Converter command line tool from AC Productions Ltd. in a scheduled batch file, which also transfers it to the webserver. The actual audio blog web page is built on-the-fly using a PHP script which checks for the presence of sound files, and similarly-named text and image files, in a particular folder. These are listed chronologically and for each one, if they exist, a JPG image or TXT file are also displayed; these latter files are the only ones that are created by hand - the rest of the system is automatic.
For 2006, we have added additional kit to enable Lorenzo to send back photos. He has a Canon Powershot A85 digital camera (chosen because of its small size, excellent image quality and use of readily-available AA batteries). He takes the Compact Flash card from the camera and inserts it into an expansion sleeve on the back of an HP iPAQ pocket PC running Pocket Phojo software. He then picks which images he wants to send, and the software resizes and IPTC tags them, then transmits them via FTP using a Bluetooth link to the BGAN terminal. In theory, the data rate exceeds 450kbps, but to cut transmission time we shrink the images to websized before transmission.