CSS Radar effect

Radar Effect Preview

Implementation

.radar {
  position: relative;
  overflow: hidden;
  width: 300px;
  aspect-ratio: 1;
  background: #00000012 url(https://i.sstatic.net/vY6Tl.png) center / cover;
  border-radius: 50%;
  z-index: 99;
}
 
.beam {
position: absolute;
  top: 150px;
  left: 150px;
  width: inherit;
  aspect-ratio: inherit;
  background: radial-gradient(12% 21% at 11% 84%, rgb(1, 99, 190) 20%);
  animation: 5s rotate linear infinite;
  z-index: 100;
  width: 150px;
  height: 2px;
  transform-origin: left;
}
 
@keyframes rotate {
  100% {
    rotate: 1turn;
  }
}

and the markup:

<div class='radar'>
  <div class='beam'></div>
</div>