- #Wxtoimg image shifting how to
- #Wxtoimg image shifting install
- #Wxtoimg image shifting full
- #Wxtoimg image shifting software
- #Wxtoimg image shifting code
It always differs from gpredict by about an hour. After much experimentation, I still could not get predict to give the correct time. The first line gives the time to start recording and the last when to stop - or you can simply stop recording after 15 minutes, but note that the time is in UTC, so you have to add your time zone offset. Single pass after sunrise on a specific day: Single pass after now (useful from a crontab): Passes between two dates (in seconds since UNIX epoch): It can be used to get the pass data for a satellite for use in scripts, in order to automate a weather map system. There is also command line version called predict. Enter your own ground station co-ordinates and then if you hover the mouse over a bird, you can see how many minutes are left to reach your position. There is a tiny down arrow at the top right, select Configure, then scroll down to the NOAA sats. You need to select the satellites that you want to track, but it is not immediately obvious how. The web site is very useful, but the best way to see when a satellite will pass overhead is with gpredict. All the same, just a bit easier, since the repositories have what you need and you won't need weird paths - everything will be in the usual places.
#Wxtoimg image shifting install
You need to install rtl_sdr, gpredict and WXtoImg. So, for Linux users, it is the same idea as in this article.
#Wxtoimg image shifting software
Note that the future NOAA software systems will all run on Linux and other operating systems will be supported through Linux virtual machines only, as explained here This sorts out all the library dependency issues for your system, with the result that specialized scientific and engineering software generally work much better than on other systems.
#Wxtoimg image shifting code
On these UNIX systems, Free software is installed by downloading the source code and compiling it on your machine.
#Wxtoimg image shifting full
Linux and BSD have good real-time performance and gives one full control over everything. With these tools, you can compile specialized software, much the same as on FreeBSD/Linux. In order to use Free scientific/engineering software, you need Xcode (The C compiler provided by Apple, in the App Store), Macports and Homebrew. However, if you use Free software, then it is much the same as Linux/FreeBSD. If it doesn't work, then you are out of luck, there is nothing you can then do about it and your project is hung - Nuf sed.Ī Macintosh system is better, since it is based on FreeBSD, but it suffers from some of the same software library issues when using precompiled (non-Free) software. The result is that if your special program happens to work, then you are in luck. The problems are many fold: The operating system scheduler is not real-time, the USB interface is buggy, scientific software invariably require specialized libraries of specific versions, which sometimes clash with libraries that are already installed - known as DLL Hell. These are generally good for playing games, writing letters and doing bookkeeping, but they are not very good for engineering use.
Most ordinary mortals use MS Windows computers. To decode it, you need a phase locked loop to convert the FM signal into a varying brightness level - simple as that. The APT signal is 2.4 kHz, frequency modulated, described here and here (APT)Įach facsimilee line starts with a tone burst and the monochrome line is encoded onto a 2.4 kHz tone by frequency modulation at a rate of two scan lines per second.
All three satellites broadcast using an ancient system termed Automatic Picture Transmission (APT). NOAA-15, NOAA-18 and NOAA-19 are probably the easiest to interface to. You also need to make a decent antenna, else you may have more noise than picture. These pictures are interesting, since the weather is always changing.
#Wxtoimg image shifting how to
This article describes how to get an image from one of the NOAA polar satellites, using a cheap ($25) little RTL-SDR radio receiver. The geo satellites can only be received if you happen to live in its antenna footprint (North America), while the polar satellites pass overhead twice a day wherever you are.
The NOAA operates both geostationary and polar observers.
Weather satellites are generally considered to be the most useful of the lot, since the data is open and not encrypted and the signals are quite strong.