Welcome to POES-Weather Ltd
Remote Sensing and Software Consulting

POES-Weather Ab/Oy Ltd was formed on 7th October 2010, a private company limited by shares.

Our goal is to provide enhanced high resolution satellite imagery from polar orbiting weather satellites. Images will be used for forrest fire detection, snow and ice detection, special imagery and services for Finnish agriculture, climate research and environmental monitoring in general.

Our main task, 2011, will be to provide more reliable, up-to-time, local weather information and services for farmers and public in Finland using local weather stations and satellite imagery.

POES-Weather Ltd is opensource. We use Qt as software development platform and Linux Fedora as operating system.

APTDecoder, The NOAA POES APT Weather Satellite Decoder

APTDecoder is a free software for recording and decoding signals transmitted by NOAA POES APT enabled weather satellites. It is run on a NT-based version of Windows. A minimum of 128 MB of RAM is recommended. More RAM is needed if you use background images as templates. We recommend 512 MB and to be safe 1 GB of RAM and a P4 computer.

APT: Automatic Picture Transmission. A method of broadcasting cloud pictures from satellites.

APT data are transmitted continuously as an analogue signal using amplitude modulation of a 2400 Hz carrier. A new line of data is transmitted each half second containing a line of image data from two AVHRR channels together with supporting information. As each image frame is received, synchronisation patterns show up as vertical black lines to the left of each image while telemetry data are shown as grey scale wedges carrying calibration and other information. Any two of the Advanced Very High Resolution Radiometer (AVHRR) channels can be chosen by the NOAA ground station for dissemination. A visible channel is used to provide visible APT imagery during daylight, and one IR channel is used constantly (day and night). A second IR channel can be scheduled to replace the visible channel during the night-time portion of the orbit. To receive APT you need a PC, 137 MHz receiver and a dedicated right hand polarized (RHCP) antenna.

For more information see NOAA KLM USER'S GUIDE Section 4.2 (http://www2.ncdc.noaa.gov/docs/klm/html/c4/sec4-2.htm).

The general idea of this software is What You Receive Is What You Get, WYRIWYG. It does not modify your received image before you say so.

APTDecoder can create four grayscale- and colour enhanced images. Coloured images are created based on an colour lookup table (CLUT). A CLUT editor is also included. It renders the raw image (fully decoded) while recording signals transmmitted from the satellite or while processing an audio file.

It can track multiple satellites, displays satellites on a map, predict passes and footprint overlaps on a given date. Orbital elements can be downloaded and updated from a user specified url or local file.

APTDecoder has radio control support for R2FX, RIG-RX2, EMGO and ICOM PCR1000/1500/2500.

It has an advance HTML/RSS 2.0 logging system. It automatically maintains the log after the pass is recorded and uploads it to the user specified server. Logs are overwritten every day. An RSS feed reader is built-in.

An example image captured over my station and decoded with APTDecoder. This image was transmitted by the latest launched satellite, NOAA 18 (N), on 137.9125 MHz. It was launched from Vandenberg Air Force Base, Calif. at 6:22:01.566 a.m. EDT Friday, May 20 2005. Read more at NOAA N Mission home. It was recorded on Tuesday, May 31 2005 at 09:44:05-09:55:29 UTC, maximum elevation was 35° and moving north.

The image to the right is poes-weather latest received APT image at Vasa Finland.

APTDecoder is free software: It is derived from the work by Thierry Leconte, F4DWV and can be found at http://atpdec.sourceforge.net/. Mapping is done with the open source Geographic Translator (GEOTRANS) and satellite tracking and orbital prediction program PREDICT written under the Linux system by John A. Magliacane, KD2BD. Images are generated with the ImageMagick software suite.

It is delivered with source code, you can redistribute it and/or modify it under the terms of the GNU General Public License.