The signal mirror, or as the heliograph calls it in special literature, which literally means writing with the sun, explains its purpose. Many types of signal mirrors are known, which are presented in a large variety in catalogs on tourist-oriented sites..
Signal Mirror, Ultimate Survival Technologies Starflash Heliograph, Overview and Impressions.
It is estimated that the brightness of the light signal bunny at an angle of the sun at 90 degrees is nearly 7,000,000 candles. A flare of a signal mirror on a cloudless, sunny day is detected from an airplane flying at an altitude of 1 2 km, at a distance of 20 25 km. In some cases, up to 60 km. A signal mirror can give a signal not only during the day, but at night in the full moon and even in foggy haze.
The presented Starflash signal mirror manufactured by Ultimate Survival Technologies, size 7.5×5 cm, is made of high-impact Lexan polycarbonate plastic. It weighs 20 grams and has a little ring for a dark spot. On the back there is an instruction for use in English.
The design of this signal mirror is somewhat different from the usual domestic mirrors. It is simpler and more convenient to use. There is no need for the sunspot visible on the back of the signal mirror that has fallen on the matte leaf to be continuously combined with the hole. Accompanying a moving target.
. The proposed video shows the visibility of the heliograph signal at ranges of 1.1, 17.8 and 69.2 kilometers.