First steps – video from space

Video Space

There are many Satellites in orbit today capable of recording video from space; there is even a camera attached to the ISS. This is a relatively new and exciting area in Earth Observation.

I say new… this article is almost four years old at the time of writing.

https://blogs.scientificamerican.com/plugged-in/high-definition-video-from-space-is-available-for-purchase-finally/

What does this mean? Is anyone using this data at the moment? If so, not much is being said about it. Four years on from this article we are still in the ‘bringing this technology to market’ phase, or so it seems to me.

With this in mind I asked a question on LinkedIn – “Video from space – ‘Hot’ or ‘Hype’?”. Do please add your thoughts.

https://www.linkedin.com/feed/update/urn:li:activity:6330802508797214723

I’ll try to summarise the consensus of current thoughts here:

  • Video on its own is pure hype.
  • Data from video enabling the generation of 3D models (buildings for example) is hot.
  • If something is rapidly changing and you can record it and deliver it fast from the sensor then that is hot.
  • Combining data with video has the potential to be hot.
  • The value of temporal data depends very much on what you are mapping / monitoring. Maybe an image every day is more applicable, or one every 5/6 days provides the information required.

An example of data

The video below is from Carbonite-1, built and tested by SSTL in an incredible 6 months. It provides an 11 second burst of information.

You can read video files in OpenCV, like you would read any kind of video.

import cv2
cap = cv2.VideoCapture('video.avi') #or .mp4
while(cap.isOpened()):
    ret, frame = cap.read()
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    cv2.imshow('frame',gray)
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
cap.release()
cv2.destroyAllWindows()

To perform edge detect add the following lines after line 6

edges = cv2.Canny(frame,100,200)
cv2.imshow('Edges',edges)

Video can be saved using the script in the OpenCV documentation.

It should be possible using contouring and filtering on the size to just pick up the vehicles and count them, and getting speed should also be achievable. You could argue that you could calculate the speed with just two frames.

Just last month six more skysats are up:

Earth-i is also set to launch their first satellite later this month and has ordered more

 

One thing is for sure: video from space is not going away. The way things are shaping up 2018 might well be the year for video from space.

I am a freelancer able to help you with your projects. I offer consultancy, training and writing. I’d be delighted to hear from you.

I have grouped all my previous blogs (technical stuff / tutorials / opinions / ideas) are here http://gis.acgeospatial.co.uk

I am @map_andrew on twitter