Optimizing Lidar Collection with Advanced Flight Management

The success of an aerial acquisition project, whether lidar or imagery, depends on taking advantage of acquisition days to turn around the project quickly. Surdex accelerates schedules by using a collection of flight management tools to make the most of suitable flight conditions and re-routing aircraft around poor conditions, thereby reducing the time the fleet is on the ground.

For a recent lidar GPSC3 Task Order from USGS, the Merrick-Surdex Joint Venture collected 5032 square miles of QL1 lidar data in Arizona. The acquisition was complicated by 2020 west-coast summer and fall wildfires adding atmospheric issues that affected aircraft operations across the US. Using its flight management tools, including a near-real-time aircraft tracking tool called FlightTracker, Surdex flew the project with optimal efficiency. The hallmark of the Merrick-Surdex Joint Venture is on-time delivery for USGS GPSC Task Orders.

Surdex’s flight management system includes real-time monitoring and communications measures to direct aircrews to the most advantageous acquisition conditions:

• Flight conditions: online weather forecast, satellite feeds, leaf-on/off predictions, fire/smoke obfuscation to ascertain real-time flight conditions
• Continuous monitoring: Flight Operations monitors conditions of all flight areas every day to apprise air crews of changes in conditions
• Rapid communications: aircrews are informed via text messaging to divert from problematic areas to areas of favorable conditions, reducing the need to land for updated directions

Contending with wildfires and smoke

For the USGS Arizona lidar project, the significant number of wildfires exacerbated issues with visibility and data collection. Heavy smoke over a project area and other atmospheric conditions weaken the intensity of lidar returns, sometimes requiring re-flights to ensure sufficient point density is achieved.

The time delay between acquisition and data inspection creates a domino effect, since additional delay may arise before re-flights can be planned. Re-flights impact schedule during the project flight window. The solution is to work around smoke-affected areas to reduce re-flights.

During the first few days of the Arizona project, Surdex experienced sit days, creating concerns that the project schedule would fall behind. The project area included restricted airspace, adding another complication.

Building the solution

To better manage flights around impacted areas, Surdex’s R&D staff searched for real-time or near-real-time sources to incorporate a wildfire prediction layer into the FlightTracker system to improve mission planning. The size of the Arizona project area demanded better information to make informed decisions for areas impacted by wildfire smoke.

The solution was to incorporate a near-real-time layer of fire data into the FlightTracker system, which allows for data layers to be added, providing additional valuable data for analysis and flight planning. In this instance, we identified three data layers that would address issues pertaining to fires and smoke.

• NASA Fire Information Management System. This layer provides active fire data within three hours of satellite observation from both a moderate resolution spectroradiometer and a visible infrared imaging radiometer suite. The data is available in multiple formats compatible with FlightTracker’s multilayer scheme.
• NOAA Smoke Forecasting data feed. The data provides 48-hour predictions for smoke dispersion and concentration used for air quality forecasts from the NOAA GOES satellite observation.
• AirNow. This data was added to indicate air quality, which factors in wildfire smoke. AirNow was originally developed by the US Environmental Protection Agency. It is now a partnership of seven US agencies and Environment Canada, which are responsible for updating the US Air Quality Index (AQI). AQI is forecasted for major cities across the US with wildfire smoke included as a variable in air quality. AQI predictions are based on ground observations and satellite data.

The smoke and fire data sources in FlightTracker appear as layers that can be toggled on or off if smoke is a factor during collection. All the other FlightTracker features such as aircraft location and cloud conditions contribute to successful mission planning and execution. This brings reassurance to a client with a FlightTracker link and improves decision-making for aircraft movement by Surdex Flight Operations.

Implementing the tool

These three data layers were identified and quickly added into the FlightTracker system, and Flight Operations and flight crews were trained on their use. The prevalence and severity of wildfires had created conditions that affected many areas other than Arizona, and the solution could be instituted across the country. During mission planning, the fire and smoke layers viewed in FlightTracker proved extremely valuable, and Flight Operators could text air crews, notifying them when shifting winds moved smoke into planned flight lines.

The layers also proved extremely useful during numerous projects in southern Florida, where post-harvest burns in sugar-cane fields often occur on days that normally would have been ideal for data collection.

How Surdex’s flight management works

Clear flying time is a limiting factor in every project, and aircraft operations are expensive. To optimize collection efficiency and manage costs, it is imperative to keep aircraft operational—and that means flying in conditions good for lidar collection.

Surdex’s answer is a coordinated system of data collection, analysis, communication, and redirection.

• Twice daily, Surdex Flight Operations reviews the location of all Surdex aircraft to evaluate conditions within each project area and identify favorable acquisition conditions for the next 24 to 72 hours.
• Flight crews are directed via text messaging after each Flight Operations meeting to remain on their current mission, change locations within the project area or mobilize to a different project with optimal collection conditions to avoid downtime.
• Project managers use FlightTracker for interim status checks throughout the day, either from the office or via a smart phone app developed for FlightTracker. In cases where it is not necessary to land and refuel, Surdex flight management has extended the average annual on-line time for Surdex aircraft up to 30% in the past several years.
• FlightTracker, in addition to onboard texting by flight crews, allows movement within a project AOI or to other projects, eliminating the need to land and get instructions. This maximizes acquisition time when conditions are optimal.

Client FlightTracker

Internal use of FlightTracker has proven so successful that Surdex adapted a version for client use. Many clients have a sense of urgency about acquisition, and this tool enables them to follow individual aircraft during the acquisition of their projects. The system continuously reports an aircraft’s status, whether it is over the project area, headed to the site, returning from the site, or stationed at a local airport. It also provides airborne data such as the aircraft’s airspeed and flight altitude.

With FlightTracker, clients can see precisely how much of the project has been completed and how much has yet to be flown. In conjunction with satellite data, it is easy to see areas of current and upcoming cloud cover.

The system is configured to allow users to see only their own project areas and allows Surdex to manage multiple projects across the country, relocating aircraft and sensors to capitalize on ideal acquisition conditions.

Clients view Surdex FlightTracker as another communication tool during acquisition, eliminating doubts as to progress and expected completion. FlightTracker’s advanced weather predictions, including cloud movement coupled with other environmental issues impacting data collection, provide status, improve efficiency, and contribute to flight crew safety.

FlightTracker helps completion of Arizona acquisition

Surdex Flight Operations included smoke predictions to manage aircraft location within the Arizona AOI for each mission to reduce or eliminate sit days and minimize downtime and re-flights. The smoke tracking feature incorporated into FlightTracker contributed to successful completion of data capture at the end of November 2020. The Merrick-Surdex Joint Venture completed collection on time.

FlightTracker is a custom online tracking tool that incorporates data feeds from several federal agencies into a cohesive framework to display all issues that affect airborne data collection. It is a client “feel good” value-added service as well as a critical Surdex Flight Operations management tool. In the Arizona project, the smoke detection feature of FlightTracker in conjunction with the use of the Optech G2 sensor system during acquisition had positive results.