Aerospace and Electronic Systems Magazine June 2017 - 25

Resampling and its errors can be removed by changing the way
the image processing chain is implemented. The traditional SET
model is shown in the upper diagram of Figure 1. In the traditional
model the image is projected, resampled, compressed, and then
transmitted to the end user via a data link, or storage device. The
SET tool displays the data. In the revised model shown in the lower
diagram of Figure 1, the raw image is compressed and transmitted
to the user. The SET then decompresses the image and displays
the image using an algorithm similar to the Matlab® pcolor function. In the pcolor function the pixel is displayed as a trapezoid, as
shown in Figure 2, and no resampling is needed. As the image is
projected, each pixel's trapezoid can change shape and orientation,
as well as intensity, depending on the zoom level, and the location
of the aircraft with respect to the ground location.
Image resolution directly impacts the extraction of usable information from WAMI data. Improving
resolution improves the performance
of both automated trackers and manual analysis. In this article, the loss
of resolution is traced to the resampling process. To eliminate the resampling errors a novel SET model is
proposed. This SET model improves
resolution and increases the information extracted from the data.

data set is introduced in [8]. The WPAFB 20091021 data set consists of raw and projected data. The raw data consists of six raw
images, and a pose file for each frame. The pose files include the
flight number, frame number, camera position in Latitude, Longitude, and Height (LLH), the camera attitude in Roll, Pitch, and
Yaw, and other information not used in projection. The flight number and frame number are used to match the images with the pose
data. The projected images are in National Imagery Transmission
Format (NITF) [9] format.
The camera models developed in [8] are used to project the raw
images. There are six camera models, one for each subimage. Each
camera model consists of six parameters. There are three parameters
for the Camera Perspective Center in pixels, and three parameters for
the angular alignment between the individual cameras and the Inertial

DATA SET
The data set used in this article
comes from a flight test conducted
on October 21, 2009. The data set is
distribution "A", public release. In
addition, the projection parameters
from a later flight conducted on October 20, 2010 are used.
The data set used here is available from Air Force Research
Laboratory Sensor Data Management System public web site, at
https://www.sdms.afrl.af.mil/index.
php?collection=wpafb2009.
This
JUNE 2017

Figure 2.

The Matlab® pcolor function is used to paint the individual pixels as a trapezoid.

IEEE A&E SYSTEMS MAGAZINE

25
https://www.sdms.afrl.af.mil/index.php?collection=wpafb2009 https://www.sdms.afrl.af.mil/index.php?collection=wpafb2009
Table of Contents for the Digital Edition of Aerospace and Electronic Systems Magazine June 2017
