Images Captured by a Skyward Drone
Firing Images from 30 km Up: A Ham's Adventure with SSTV
Have you ever pondered how to capture images from an altitude of 30 km? A creative inventor decided to give it a shot, employing a technique known as Slow Scan TV (SSTV), a method once used by hams to trade memes before the Internet era. If this concept is foreign to you (pun intended), let me explain.
SSTV is a method of transmitting images over radio waves at a low frame rate, making it perfect for long-distance communication. The setup typically involves cheap walkie-talkies and an ESP32-CAM for image acquisition and processing. Contrary to popular belief, these radios may seem insignificant in terms of range, but when paired with a high transmitter, the range can extend exponentially.
The ESP32-CAM module is incorporated in this setup, serving as the primary image capturer. This module boasts a camera and a microcontroller that processes and encodes images for transmission. The walkie-talkies are employed to radio these encoded images, though these radios may need some additional circuitry to handle the SSTV encoding and transmission protocols.
If you're SSTV-savvy, the ESP-32 code encodes the image using the Martin 1 color format, developed by ham enthusiast [Martin G3OQD]. A 320×256 image takes nearly two minutes to transmit. The balloon system sends an image every 10 minutes, so time isn't an issue.
To receive SSTV signals, you don't need to worry, as the process is straightforward. Just tune into the correct frequency and prepare to decode the incoming images.
This technique is versatile and can be applied to send images through any communication medium. SSTV protocols are robust and functional even on the noisiest shortwave frequencies, making it a go-to method for ham enthusiasts worldwide.
SSTV images transmitted from high altitudes can provide valuable data for meteorologists, researchers, and anyone with an interest in monitoring environmental changes from space. So, if you're intrigued by the idea of trading images from the skies, grab your walkie-talkies, ESP32-CAM, and let your creative side soar!
The inventive ham utilized Slow Scan TV (SSTV), a technique that transmits images over radio waves, employing inexpensive walkie-talkies and an ESP32-CAM module for acquisition and processing.
The versatile SSTV method can be used to send images through various communication mediums, providing valuable data for researchers and meteorologists, even on noisy shortwave frequencies.
