We identified the sensor suite, the current state, the gaps, and the transition plan to get sensors ready for this mission. The miniaturization process will actually increase the performance of the microwave sensors – this will create a larger surface area for the antennae. This will probably force us to use dedicated aircraft for these sensors.

The visible and IR sensors need larger collecting optics. We cannot miniaturize them, but we would like to create larger collecting optics on a lighter-weight sensor. This will increase performance per unit weight.

Some of the other sensors are off-the-shelf products.

This suite of sensors solve a number of other science challenges, not just the cryosphere. We can look at volcanoes, solid earth geology, etc.

To do high-sensitivity measurements, we need a platform that can go very low and slow, while maintaining a constant land speed – this is critical for these kinds of remote sensing instruments. This gives us a much better signal-to-noise ratio. We would love to get a ground speed of 5 knots, but this would require some serious headwinds.

Most of these sensors are pretty well-developed. The passive STAR is the least developed – this is the biggest technology gap. All of the others need to be repackaged and miniaturized, which will actually improve performance.

Operationally, cloud cover will be an issue for some of our objectives. We want to record data on board, and we will need on/off commands for some data sites. We do not see any issues for logistics and deployment. This is pretty standard operationally.

The total payload will probably be just under 200kg. It seems like a good Predator package, but it should all be measured under 12,000 feet.

We need to pay attention to any extra power that might be required to heat these instruments in extremely cold conditions.

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We’re talking about a remote UAV flying above an outflow UAV above the clouds, a convective (in-situ) UAV in the clouds, and an inflow UAV below the clouds.

For the remote UAV, there are two LIDARs and two RADARs for aerosol sensing. We will have an optical imager, lightning detector.

For the inflow, we will measure water vapor, aerosol sizing, meteorological parameters (especially wind), and aerosol composition.

For the outflow UAV, we will measure water vapor, the total water, ice particles, aerosols, water isotopes, the cloud extinction coefficient, radiative fluxes, temperature profiles, and the composition of the ice nucleus.

For the convective UAV, we will measure water, ice, chemical tracers and lightning.

On our board, we indicated the priority for each of these instruments. H means high, M is medium, and L is low. For the three lower-flying platforms, we have extra space but we are a little bit overweight (about 10-15%). Many of these sensors will be smaller in five years. The real problem we have is power, and there’s not much we can do about it in the instruments. Many of the probes hang outside the UAV, they need to be de-iced, and that required power. The aircraft guys have to give us more power – up to 5.7 KW.

In the remote UAV, the numbers are huge. We need 16 cubic feet, 755 pounds, and 4.35KW. We hope that the next generation of instruments will combine the functions of multiple instruments of today – this would save us on weight and power demands. Let’s combine the LIDARs and the RADARs as much as possible. If we can do this, we get much closer on all of the parameters for today’s high flyer.

There are some integration issues that we need to consider. Some instruments need to be easily accessed after a flight. Some detectors need to be cooled with liquid nitrogen. Many instruments have external parts (probes, optical windows, etc.), and these parts need to be accommodated by the platform. The water vapor detection inside the convective system might be problematic.

We do not have a satisfactory solution for measuring total water or condensed water content – the current solutions require far too much power and weight. We need onboard calibration gasses in order to measure some trace gasses.

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For this particular application, we do not think that there is any UAV-specific advantage. These missions are short-duration, there are no opportunistic measurement requirements (vegetation tends to change quite slowly), and alternative approaches exist. There are a lot of technologies used for other applications, however, that could be used for our purposes.

What is the magnitude of vegetation? What is the carbon change direction? How does vegetation affect the carbon cycle? What are the implications for _______ health?

We want to use radar, hyperspectral radar, LIDAR, and an on-board recorder. Some of these technologies need to be adapted to the UAV platform, but this is not a major hurdle. There are some key components that will be required for the antennae, telescope, and focal point array.

There are some general technology challenges for the UAV. It requires autonomous operations because it uses different platforms. It requires a steerable antenna. We need to be able to correct the flight path in-flight. We need high-power modules.

A 12 hour mission could generate up to 7 terabytes of data, given the instruments onboard. There are no real-time requirements for this data, so we do not need instantaneous access to it. We need to find the most cost-effective means of transmitting and storing the data. We need to coordinate the flight path, but we do not need to coordinate the flight paths of multiple aircraft in formation. One UAV will have X-band and L-band, and a second UAV will carry LIDAR and hyperspectral. They do not need to fly at the same time.

There is no particular advantage to using UAV’s for this application, but it would be useful to use UAV’s to validate data collected by other means. We need to measure for about 12 hours, but it does not have to be 12 contiguous hours. We can take most of these measurements from space. If another mission is flying in this area anyway, then we would be happy to piggyback, but this probably does not justify its own mission.

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We have a long list of things we want to measure. We did not have any fire specialists on our team, but we think we did a good job. We need a long list of equipment as well. We need an aerosol LIDAR and a hyperspectal imager in the high-altitude aircraft. In the low-altitude UAV, we want a gas filter correlation radiometer, a mass spectrometer, a gas chromatograph, a spectral radiometer, etc.

From this list of instruments (and what they could measure), we tried to assemble a package of instruments that would measure the most important items, including CO and CO2. With this list, we can now talk about miniaturization to see if such an effort makes any sense. Many of the instruments are so tiny that they are essentially free for the mission in terms of size, weight and space.

We developed weight and power numbers for each item, but we have not yet summed them up. We want to use LICOR to measure CO2. We want to use a HSRL LIDAR – a very powerful instrument for this mission. Another requirement for these instruments is onboard calibration gasses.

Finally, we wanted to talk about technology gaps. We feel that the multispectral is pretty good for use today (not a hyperspectral). Many of these instruments are in pretty good shape. Some instruments need some help to run more autonomously. There are some physical limits to how far we can miniaturize the LIDAR.

We will need to package our instruments differently when we start packing them into the tight spaces of UAV’s. This is in conflict with another team’s report which encourages plug-and-play. There will be data management problems onboard the UAV.

We are still unclear about some of the parameters of this mission. We do not know how close we want to get to the fire. We do not know what the real objectives of this mission are – fire dynamics or the carbon cycle.

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We began by defining our science requirements. Our goal is to get data that we cannot get from a satellite or from a manned mission. We want a balanced, 3D “grid” of high-resolution soundings. We totaled up the weight, power, and size requirements for all of the instruments on our high altitude UAV. Our sensors (without sondes) weigh 550 kg. The sondes are an additional 316 kg. This is far too heavy for a long mission!

Our recommended solution is to deploy multiple high-altitude platforms. We would use one UAV to look at the cloudy storm eyewall with microwave and radar instruments. This would be the storm-synchronous platform. We would take the second, adaptive high altitude platform to the outer storm or the near-storm environment, where there is clear air – we’ll put our LIDARs on that vehicle.

Sondes are already being miniaturized, but one risk in this application is that the sondes will move sideways rather than vertically. Also, it does not seem to make sense to use them routinely on the remote sensing platforms because of the weight that they add to a long mission. Sondes are necessary, however, for calibration and validation of the remote data. We will put our dropsondes on another UAV to validate our remote sensing instruments.

The storm-synchronous platform must track along with the hurricane. The rate of the storm’s movement will be too slow, and the UAVs field of view will be too narrow for the UAV to stay in the “same place” relative to the storm. Instead, the UAV should follow a repeated path relative to the storm. The adaptive platform must be intelligently directed – a scientist modeling the hurricane can send the UAV to the “best place” based on an expert, subjective evaluation.

We do not believe that we have a data rate issue with our remote instruments, but we need to quality control the data very rapidly because it needs to be used in real time for forecasting. Automation is not an issue, but we need a way to talk to our instruments. We need a new technique for measuring below-surface ocean temperature – we don’t know how to do that from a UAV. An AXBT used for ocean soundings is huge, and is not practical to put on a high-altitude platform.

The concept of mother ships with daughters “re-docking” does not seem to be feasible because of the weight of both the payload and “daughters”. Also, you really want soundings to go from the tropopause to the surface. The appropriate in situ instrument package for a small platform at lower altitudes is quite manageable, but the vehicle will encounter very dangerous environments. The boundary-layer measurements might be made with remote sensors or sondes to avoid these dangerous conditions.

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There will be less than 20 pounds of sensors, and less than 100 watts of power. We are not sure that this gets us sufficient resolution. The LICOR that we used will not provide nearly the resolution that we need. The hotwire system will also not give us the resolution on the vertical winds that we need.

Once we get to 2010, we can develop a much better solution. We could develop a CO2 LIDAR. We could add a three-channel LIDAR to measure the winds. We will add a hyperspectral camera. Infrared (for looking at the sea surface) will be a challenge because of the cooling issues. An FTIR has the same cooling issues. It will take until 2010 to develop and image analysis algorithm. Developing the lightweight antennae will be one of our biggest challenges. We can increase our autonomy and our data capacity. Our total mass is less than 200 pounds and just over 1000 watts. This depends on a 3000 mile range. The speed is negotiable.

Our CO2 measurements will require even more resolution than a 10-pound LIDAR can provide. We also need really good measurements of water vapor. You run the risk of a false signature. We also need to talk to the wind LIDAR.

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