What are some possible uses for the EMSI Post-Mission Video Tracker?
In a typical use, a sensor is mounted on a pedestal that collects data on a flying target. In practice, the pedestal never perfectly tracks the flying target. In order to verify the quality of data from this sensor, a video camera is normally co-boresighted on the pedestal with this sensor. A time standard, such as IRIG, is used to time-tag both the data from the sensor and the video data. Hence, post-mission, the video data can be correlated with the data from the sensor. If the target strays excessively from the video camera boresight, the corresponding sensor data can be either discarded or possibly corrected. This is where the EMSI Video Tracker is used. Our tracker can accurately and automatically measure a time-tagged target centroid, which can then be used for editing and/or correcting the data from the sensor.
Another possible use is for accurate three-dimensional tracking of airborne targets. In this case one would have several cinetheodolites that are spatially separated. These cinetheodolites follow the target and record time-tagged video, azimuth, and elevation. A video tracker is used post-mission to refine the target's azimuth and elevation relative to each cinetheodolite. The data from all cinetheodolites is then combined through triangulation to produce accurate three-dimensional track data. In the past, cinetheodolites recorded using film and human operators had to carefully manually process each film frame. Through the use of video and the EMSI Video Tracker, this process can be automated.
How would a system be configured to post mission process time-tagged video?
A typical test range uses the IRIG time standard. Digital video tape decks (such as the Sony DSR-45 DVCAM) use a different video frame based time standard referred to as SMPTE. A time code converter, such as the ESE ES-274U, can be used to convert from the test range IRIG time to a SMPTE time code that is synchronized with the video camera's frame rate. The SMPTE time code and camera video are recorded using the DVCAM tape deck. For post-mission processing the DVCAM tape deck is connected to the PC running the EMSI Video Tracker through an IEEE 1394 firewire connection. Our video tracker software controls the tape deck, automatically tracks the data and converts the SMPTE time code back to IRIG.