The U.S. space program is taking to the skies again in southern Manitoba this summer.
They’ll be using a Second World War-era DC-3 airplane to make multiple early-morning north-south passes over farm fields around Elm Creek, Carman and Roland later this summer.
It’s all part of the U.S. National Aeronautics and Space Administration’s (NASA) flight operations over this area to capture soil moisture data.
Flights began June 8 and ran until June 20, and will begin again July 10 through to July 22 over the same region. They are being conducted as part of a joint Canada-U.S. experiment to capture moisture data using space-based satellite. The terrestrial flights help determine how accurate the satellite measurements are.
On board the DC-3 is an instrument similar to one on NASA’s Soil Moisture Active Passive (SMAP) satellite launched in 2015.
“The plane is carrying a radiometer, the same type of instrument that’s on the SMAP satellite,” said Jarrett Powers, manager of the development unit in the science and technology branch of Agriculture and Agri-Food Canada (AAFC).
“What the radiometer does is it measures the naturally occurring ambient microwave energy that’s coming out of the soil,” he said adding that moisture in the ground influences the amount of energy emitted from the soil.
The SMAP satellite meanwhile has both radiometer and active radar to detect the “return value” of the measurement, retrieving the soil moisture value in the top couple of inches of the soil.
The flights are tests of different approaches using the radiometer, and will gather data that produces global soil moisture maps to the highest possible accuracy, Powers said.
The Carman region, and one other U.S. site in Iowa, are where flights are being conducted this summer.
Carman was chosen as the Canadian site because it is one of three locations in Canada (others are in Kenaston, Sask. and Casselman, Ont.) where AAFC has installed permanent soil moisture monitoring stations. There are nine located on private farms in this region of Manitoba, and here as part of ongoing research since 2010 by AAFC to study soil moisture conditions.
This part of Manitoba area was initially chosen by AAFC because both a wide range of soil textures are represented in this area, Powers said.
“To the west of Hwy. 13 is sand but you just have to go a little bit east and you’re into the heavier clay soils. It has the whole textural range of soils on which to do this work.”
It’s also an area where farmers grow all the predominant agricultural crops, he added.
NASA approached AAFC in 2012 after learning it had established this ground-monitoring network, Powers said.
The network supports ongoing AAFC research into satellite-derived soil moisture from RADARSAT-2, SMAP and other satellites. NASA, AAFC and other organizations conducted a large field campaign in the same area in 2012, when NASA flew two aircraft carrying radar and radiometer instruments over the study area while ground crews sampled over 40 fields.
Over 45,000 soil moisture measurements were taken along with observations on soil temperature, surface roughness and soil structure from heavy clays to sandy soils. The collected data was used to calibrate and validate soil moisture retrieval models from the SMAP satellite prior to its 2015 launch.
SMAP data is becoming an important source of soil moisture data for Canada, Powers said.
Its benefits range from improved monitoring of both drought and excess moisture conditions which can inform crop insurance and ongoing government programs, to aiding and improving flood forecasting. The data will also improve scientists’ ability to predict weather and develop crop productivity models.
It will also help anticipate crop disease by giving crop pathologists more information to do risk forecasts, Powers noted.
The DC-3 flights depart early morning from Winnipeg International Airport and will be conducting north-south passes at both higher and lower altitudes around 7 a.m., he added.
To learn more about SMAP visit: http://smap.jpl.nasa.gov.