For the past 10 days we have been making real time maps of all of the sub operations at Pavilion Lake. To do this, we have written some software to generate KML files to load into Google Earth. The Intelligent Robotics Group at NASA Ames has a lot of experience with ground data systems for NASA missions like the MER rovers, robotic earth analog field tests like the Robotic Recon test in northern Arizona in June, disaster response applications, and the Gigapan camera system, we were able to put together a set of tools to support sub tracking and mapping using a lot of existing software. We call the collection of tools and processes the “Surface Data System.”
Pavilion Lake 2009 Data Map
We started with importing overlays of the bedrock geology from British Columbia Geological Survey (BCGS), as well as sonar bathymetry and sonar backscatter maps that show depth of the lake and structure of the bottom. These provide context for flight planning and for setting expectations for what we will find during the flights. In real time during the submarine flights, we get sub position every 5 seconds from the navigation computer on the chase boat. We use that to track the sub by periodically writing out updated KML files and automatically refreshing them in Google Earth as network links. A submarine icon shows the current location of the sub, and a compass rose shows bearings to indicate which way to go to reach the next waypoint. Google Earth also provides lots of measurement tools, annotation tools, and other built-in functions that we can use to annotate and analyze the map. All of this information is saved to a shared filesystem so that everyone at the camp has access to all of the same map data.
We have established an operations role on the support vessels which we call the “Science Stenographer”. That person’s job is to listen in on the voice loop and transcribe any significant observations in real time. Observations worth calling up to the surface immediately appear on the map as icons that you can click on to read the date, time, lat/long, and what was said.
My reflection in the monitor showing the stenography program
In addition, the submarines are recording video continuously. The video recorder also has an “event” button that can mark the timestamp of a significant event on the video. In post-processing, we cross-correlate the timestamps to get position, and put a preview image and compressed video clip into the map as well.
These maps have been very useful for operations, for post-flight analysis, and for planning the next set of activities. After the flights are over, the science back room immediately has the flight track as-flown and georeferenced notes from the pilots. After some video post-processing (which takes some time simply due to the quantity of data: over 25 GB of video from each flight) the video clips and video stills are georeferenced and in the map. This information has been used to modify or create flight plans in real time. As an example, one morning Margarita identified interesting sampling locations during her flight. The post-flight map was immediately used to create a second flight plan to send Ricky to those locations for sample collection that same afternoon. It has also been interesting to see all of the flights and notes and images on one map simultaneously. The team realized before the end of the field season that there were areas of the lake that had not been covered and could plan accordingly.
Georeferenced notes attached to the flight tracks in Google Earth
Without this real time information procesing and integration, it would have been too late to go back and investigate those areas during the field season. Those flight plans would have to wait for another year. In a field setting with a lot of logistics overhead and a short duration for field work, understanding the big picture of operations quickly is a big time saver.
Georeferenced tree image in Pavilion Lake
After the field season is over, the map data will be used by the team to analyse and correlate information from across the lake and across different flights to support their research, and to plan next year’s activities. All of the observations and information gathered this year bring up new questions and new hypotheses, and there is always more to study in this lake.
The images in this post show a few different views of map screens. There is also a KMZ file that you can download and open in Google Earth to see one of our flight plans and watch the time lapse animated flight track for the actual submarine positions flight as it was flown that day. Try setting the playback speed to the minimum for best results. Enjoy!
- Matt
Mars