Student information

Msc thesis subject: Using Sentinel-1 and Sentinel-2 for mapping crop emergence

This topic deals with the mapping of the moment of emergence of various agricultural crops (in the Netherlands). This information is crucial for crop monitoring and early yield predictions.
Satellite information is a potential technology to obtain this information. Both optical and radar satellite data may have value, each with its pros and cons.
The so-called groenmonitor (www.groenmonitor.nl) is a nice interface for Dutch users, and the data behind it are available for scientific research (Dutch not required).
Annual time series of Sentinel-2 (NDVI) and Sentinel-1 images (backscatter) are available for this research.

One of the important parameters in models used for monitoring agricultural crops and ultimately to come to yield predictions at an early stage, is the start of the growing season. This is defined by the emergence data of the crops. Optical satellite data, in particular Sentinel-2 with its 3-5 days revisit time, are useful to discriminate vegetation from bare soil, because they are sensitive to biomass, leaf area index and chlorophyll content. However, optical data are often hampered by cloud cover. On the other hand, radar satellite sate, in particular Sentinel-1 with its 3-6 days revisit time, are not hampered by cloud cover. So, they are more suitable for monitoring activities, but the interpretation of such data is more complicated than of optical data. The integration of both data sources has great potential.

Objectives

  • Can we get a good estimate of crop emergence date with optical satellite data?
  • Can we get a good estimate of crop emergence date with radar satellite data?
  • What is the merit of integrating optical and radar data?
  • Are there differences between crops (e.g., between winter crops and summer crops) in this respect?
  • Is there an added value of using Landsat data in addition to Sentinel-2 data? At which scale level can this information best be obtained (e.g., pixel, field, region, ...)

Requirements

  • Remote sensing (GRS-20306)
  • Advanced Earth Observation (GRS-32306)

Theme(s): Sensing & measuring