Updated WeatherFax (markdown)

WeatherFax.md

@@ -1,3 +1,7 @@
+![image](https://github.com/user-attachments/assets/d6e775b3-04c7-4651-ae37-73958e7769a5)
+
+# Introduction
+
 That Wefax App, 
 allows to  receive any HF Weather Station Brodcasting (Wefax, https://www.sigidwiki.com/wiki/WEFAX) , and decode its analogue weather fax maps transmissions . 
 
@@ -12,6 +16,7 @@ For better usability , we are internally applying that tune-offset . Therefore y
 That Wefax App is combining two consecutive demodulations. First RF USB audio baseband demodulation , and later demodulating the FM subcarrier audio baseband tones. (Audio Baseband with f_subcarrier fsc (1900Hz) FSK mod +-400Hz ; Shift White pixel +400 Hz = 2.300 Hz , Shift Black pixel -400 Hz = 1.500 Hz).  That analogue AM-FM modulation , it is commonly used in Wefax (HF Weather Fax transmissions) . 
 It demodulates APT signal of the HF weather fax maps. , and sends the demodulated low scan map APT signal in parallel to the speaker (just for our audio tuning reference ) and to the LCD display in low resolution. And it allows to the user , been able to RECORD (with START / STOP)  that map in full resolution to the SD/BMP folder.
   
+# Usage
 
 Hackrf has poor sensitivity to receive directly those HF Wefax signals, (mainly broadcasted in HF band : 3 Mhz to 16 Mhz) Normally we should better add a front up-converter with better HF pre-amplifiers and a reasonable small HF antenna. WEFAX's format is a derivative of the [Automatic Picture Transmission (APT)] originally developed for transmission from the polar satellites of the USA. WEFAX has 60, 90, 100, 120, 180 and 240 LPM (Lines per minute) speeds, and two IOC (Index of Cooperation) modes, IOC 576 and IOC 288. Most weather forecasts are sent in IOC 576. Our initial target would be , WEFAX-IOC576 standard.