Welcome to the  
SMAPEx-4 Archive
Soil Moisture Active Passive Experiment

Multi-Spectral data

Sensor box with 12 multi-spectral sensors (two upper rows) and 6 thermal infrared sensors (bottom row)
VNIR sensor (downward)
VNIR sensor (upward)
SWIR sensor (downward)
SWIR sensor (upward)

The multi-spectral measurements are made using an array of 15° FOV Skye 4-channel sensors, each with 0-5 V signal output. When installed, these sensors are configured in a similar way to the Everest thermal infrared radiometers (bottom row in first picture), such that the six downward-looking sensors have the same incidence angle and footprints as the six PLMR beams. However, to correct for incident radiation, an upward-looking sensor with cosine diffuser is also installed. Each sensor weighs approximately 400g and has a size of 8.2cm × 4.4cm without the cosine diffuser or field of view collar attached). Two arrays of 4 channel sensors are installed, with the following (matched) spectral bands:

Sensor VIS/NIR (SKR 1850A)
Channel 1
MODIS Band 1
Channel 2
MODIS Band 2
Channel 3
MODIS Band 3
Channel 4
MODIS Band 4
Sensor SWIR (SKR 1870A)
Channel 1
MODIS Band 6
Channel 2
Channel 3
MODIS Band 7
Channel 4



Created: February 2016
Last Modified: April 2016
Maintainer: Xiaoling Wu, xiaoling.wu@monash.edu