Image acquired by the VENµS satellite, 2018, over the Zin Valley, Negev Desert, Israel
The Scientific Mission of the VENμS Program
Prof. Arnon Karnieli
Agreement Sign
Vegetation and Environmental New Micro Spacecraft (VENμS)
12 April 2005
Venµs System Components
- Satellite
- Bus -based on IAI/MBT-SPACE platform
- Supper-spectral camera –El-Op (CNES responsibility)
- Hall Effect Thrusters (IHET) -RAFAEL
- S-Band Station –MBT-SPACE
- Technological Mission Center -RAFAEL
- Launch Vehicle -CNES.
- Ground Receiving Station at KIRUNA -CNES.
- International Scientific Center -CNES
- Israeli Scientific Center -BGU
Mission Characteristics
- Orbit: near polar, sun-synchronic (constant view angle)
- Altitude: 720 km
- Inclination: 98.27°
- Revisit time: two days
- Swath: 27.56 km
- Spatial resolution: 5.3m
- Number of spectral bands: 12 (VIS-NIR)
- Tilting capability: +/-30° across and along track
- Radiometric resolution: 10 bits
- Equator crossing time: 10:30 AM, descending mode
- Mission start/duration: 2018, ³ 4.25 years
1 Aug. 2017
Objectives of Missions
The VENµS program consists of two missions:
- Scientific mission;
- Technological mission
The overall aim of the scientific mission is to acquire frequent, high spatial resolution, multi-spectral images of 110 sites all around the world.
- 12 spectral bands in the visible and near infrared region;
- 2-days revisit time in a constant view angle;
- 5.3 m spatial resolution;
Payload
- a scientific component:
- a technological component:
Band Setting
Band Location
Band Location
Main Applications
Scientific Applications
Land Applications
Land Applications
Main Application - Vegetation Indices
NDVI
Advanced Vegetation Indices
Atmospheric Resistant
Vegetation Index (ARVI):
Enhanced Vegetation Index
(EVI):
Forest Variables
Red Edge and Chlorophyll
Red Edge line shifts to longer wavelengths during plant growth and to shorter wavelengths when the plant is under stress and during senescence;
Red-Edge Bands Setting
Red Edge Position
After Guyot and Baret, 1988
REIP for LAI Assessment
Nitrogen in Wheat and Maize
Chlorophyll Index
Soil Indices
(Karnieli, 1997)
(Ben-Dor et al., 2006)
Water Applications
Water Applications
Coastal and Inland Water Applications
Monitoring chlorophyll that indicates pollution or sediments transport.
Water Spectra
Atmospheric Applications
Water Vapor Bands
Aerosol Optical Thickness (AOT)
Aerosol Optical Depth @550 nm
Monitoring aerosols such as dust, biomass burning smoke, volcanic ash, or anthropogenic air pollution.
Digital Elevation Model (DEM)
Digital Elevation Model
VENµS Camera
Venus DEM
Duplication of 638 nm band, with such an arrangement in the focal plane that the line of sight of the two 638 nm bands differs by an angle of 1.45 degree (Δt = 2.7 sec).
DEM Application
From this small stereoscopic effect it will be possible:
- to generate elevation, slope, aspect, drainage basin, etc.;
- to detect clouds by their altitudes.
Revisit Time Advantages
GSD Vs. Off-Nadir Angle
Dynamic Land Cover / VI Monitoring
Land-use & land-cover Classification
Classes are separated by using their spectral and temporal profiles.
Time series of images increases the classification accuracy.
Pollution Dispersion –11 –25, June 2001
Cloud Mask
VenµS combines 2 methods for clouds detection
Multi-temporal analysis of the surface reflectances
Clouds altitude detection by stereoscopy, computation of the location of clouds shadows
Product Levels
Location of International Sites
Strips over Israel
VENµS Strips and Agriculture Areas
Parks, National Reserves, and Forests
LTER Sites
Water Reservoirs
Imaging over Israel
Start: 10:30 AM
12 tiles, 36 sec
Forward view
Satellite maneuvering
5 tiles, 20 sec
Backward view
Satellite maneuvering
10 tiles, 30 sec
Backward view
Summary
Uniqueness of the VENµS system:
- Combination of high spatial, spectral, and temporal resolutions;
- Technological payload.
- High spatial resolution for monitoring individual fields and provide information for precision farming.
- Several bands, including along the red edge for assessing the state of vegetation;
- Several bands for assessing water quality.
- High revisit time to acquire rapid changes of vegetation and water quality, as well as for cloud mask.
- Duplication of the red band to produce DEM;
update: 22 May 06
