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SLAP/LIAISE Paper Published

01 December 2023

"High-Resolution Soil Moisture—a European Airborne Campaign Using NASA Goddard’s Scanning L-Band Active Passive (SLAP)," which describes the results from SLAP collected during the Land surface Interactions with the Atmosphere over the Iberian Semi-arid Environment (LIAISE) field campaign, has been published in the journal of Remote Sensing in Earth Systems Sciences.

DOI: 10.1007/s41976-023-00099-4

SLAP Campaigns

SLAP Data

Data Download

The geolocated radiances and geophysical parameters collected by SLAP are posted on the page for each field campaign as they become available. Please explore the list of field campaigns to learn about the flights from each campaign and download SLAP data.

For older versions of SLAP data, the entire published data archive can also be found on Box.

Field Campaigns

FireSense 2023

Date	Name	Take-off Time	Take-off Airport	Landing Time	Landing Airport	Target Site	Note
Sep 25, 2023	SF01	8:30 PDT (UTC-7)

IPHEx 2014

IPHEx Campaign, North Carolina 2014

The Integrated Precipitation and Hydrology Experiment (IPHEx) centered in the Southern Appalachians and spanning into the Piedmont and Coastal Plain regions of North Carolina held a campaign to characterize warm season orographic precipitation regimes, and the relationship between precipitation regimes and hydrologic processes in regions of complex terrain. As part of the IPHEx2014 experiment SALP participated to collect soil moisture measurements for ground validation.

SLAPex LIAISE 2021

•HBG 111 team operated the GSFC SLAP airborne soil moisture sensor in Spain to participate in the LIAISE irrigation study during its two-week special observation period (SOP)

•Nine science flights were flown during the SOP to capture soil conditions during planetary boundary layer formation

•Flights were coordinated with the LIAISE science team, who operated in situ soil sensors, flux towers, tethered balloons, and radiosondes from multiple locations in the science target area

Space Missions

Research Areas

Biosphere Instrument Calibration

GSFC laser calibration setup (courtesy Joel McCorkel)

Outreach

Earth Observatory

Explore the causes and effects of climatic and environmental change through the use of real satellite data.

Website:

https://earthobservatory.nasa.gov

Data Files

SLR Time Variable Gravity

Satellite laser ranging (SLR) tracking data provides more than four decades of measurements useful for estimating the long wavelength components of time-variable gravity, including C20 and C30. The estimation of these gravity coefficients with SLR has been critical to the success of the GRACE and GRACE-FO missions. GSFC routinely provides estimates of the gravity coefficients up to degree and order 5.

NASA-USDA Global Soil Moisture Data

The NASA-USDA Global soil moisture data provides soil moisture information across the globe at 0.25°x0.25°spatial resolution.

GEODYN Documentation

GEODYN is used extensively for satellite orbit determination, geodetic parameter estimation, tracking instrument calibration, satellite orbit prediction, as well as for many other items relating to applied research in satellite geodesy using virtually all types of satellite tracking data.

Instruments

SLAP Thermal Infrared

SLAP’s thermal infra-red (TIR) sensor is used to estimate the physical temperature of each footprint on the ground during a science flight. This information is needed by many algorithms—for example, the L2 passive soil moisture algorithm. SLAP uses the CTF-SF15-C1 made by Micro-Epsilon for this measurement.

Organizations:

Hydro

SLAP Radar

The radar in SLAP utilizes simple scatterometer design with single string used as transmitter and simultaneous V and H chains used as receivers. It provides VV, HH, VH and HV polarization channels. It operated at radio frequency of 1.2625 GHz with flexibility for adjusting to RFI frequencies. It transmits power of 50 W with duty cycle of 0.2%. Internal hot and ambient loads, external anechoic foam and cold sky were used for calibration purpose.

Organizations:

Hydro

SLAP Radiometer

The Scanning L-band Active Passive (SLAP) instrument includes both a radiometer (passive microwave) and radar, operating with the same frequencies, polarizations, and conical scan geometry similar to that of the SMAP (Soil Moisture Active Passive) space mission. The SLAP radiometer operates at 1.4 GHz and features the same fully polarimetric observations with similar radio frequency interference (RFI) detection and mitigation capabilities as the SMAP radiometer.

Organizations:

Hydro

Models

SWATOnline Web-based Decision Support Tool

SWATOnline is a web application developed for hydroclimatic application to leverage data sharing capabilities employing current web technologies. The SWATOnline web app can be duplicated, installed, and hosted anywhere. The work presented in this web app represents an effort to lower technical barriers for the Soil and Water Assessment Tool (SWAT) model through using open source web development, web services, and cloud storage technologies.