AbstractAbstract OutputOutput

In this project, we develop a MATLAB model that simulates infrared (IR) images of the Earth from old IR weather images. These images are necessary to develop and test data compression algorithms for the images of Earth taken from space using an IR camera. None of the existing databases of IR images consider the factors like the location of the satellite, orientation of the camera, etc in their images.  We consider the position of the satellite along its orbit and provide the information about the exact location and orientation to the image generation module, which transforms the images in the original database to make them look like images taken from the camera at its current location.  The simulations produced reasonable IR images of the Earth and these images can be further improved with a good initial database. With this realistic database of IR images, we expect to provide a good training and test dataset for the image compression algorithms, which are developed as the second part of the CubeSat project.

Michael Scholl, Arye Nehorai (Advisor), Ed Richter (Advisor)Department of Electrical and Systems Engineering

OverviewOverview

Methodology

Future WorkFuture Work

GoalGoal

• Study the use of a microbolometer array in low Earth orbit for taking infrared images of propulsion system plumes as well as Earth's atmospheric and oceanic conditions.

• Develop an accurate model of infrared images of Earth from space taking into account the location, and velocity of the camera.

• Develop algorithms for image selection and compression so only interesting images are compressed and transmitted.

ApproachApproach

• Gather a database of infrared images of Earth with location and orientation data.

• Create a model that uses this database to produce a series of images for a given location and velocity.

•Develop and test algorithms for selecting and compressing images based on the model.

• Compare images to real images gathered from infrared cameras on a CubeSat and adjust database and model.

ApplicationApplication

Testing communication systems for satellites studying propulsions system plumes or oceanic conditions.

Figure: Flowchart for generating an image from the position of the satellite

SATELLITE COMMUNICATION SYSTEM: PART I – MODELING THE IR IMAGES

Related WorksRelated Works

Figure: First output from a run where the satellite starts near India and moves south and west.

Figure: Second output from a run where the satellite starts near India and moves south and west. At this point the satellite is off the east coast of Africa.

The output of the simulation shows a 3D graph with the location of the camera with respect to the Earth in the upper left, the image the camera took in the upper right, and the original image with center of the image marked with a point on the bottom.

•Take into account the orientation of the camera

•Simulate the sun

•Upgrade the database of images by launching a CubeSat with infrared cameras on it (in conjunction with Saint Louis University)

Figure: Saint Louis University’s CubeSat design (Source: http://cubesat.slu.edu/)

Gu, Alex, “Satellite Communication System: Part II – Image Data Compression”

Saint Louis University CubeSat project, http://cubesat.slu.edu

Generating Images

1. Load an image from the database

2. Calculate the initial position

3. Generate an image for the position

4. Display output

5. Determine the next position

6. Repeat steps 3-5

Calculate the height and width of

the final image

Calculate the starting pixel of the

image

Copy the selected part of the original

image

Original image does not cover the entire

area needed

Adjust the image by concatenating

white pixels (representing the

polar caps)

Should the image include

space

Determine which parts of the image should be space and replace them with black pixels

Is scaling turned on

Scale the image to 320 by 240 pixels

Return the image

Yes

No

Yes

Yes

No

No

Figure: Combination of IR photographs of the Earth from space (Source: http://www.metoffice.gov.uk/weather/satellite/)