The ICEYE constellation, as of the beginning of 2021, consists of seven operating X-band Synthetic Aperture Radar (SAR) satellites. Over the next years, ICEYE will continue to grow its constellation capacity in specialised orbital planes designed to provide persistent monitoring capabilities and high resolution view of the Earth's surface. The ICEYE vision is to bring a new service to the market with an emphasis on superior reliability, a vastly higher rate of revisits to individual locations, and an unprecedented objectivity. The service is based on a completely new satellite and sensor design, leveraging recent advancement in various technologies and the New Space approach.
Each ICEYE satellite is in a sun-synchronous orbit with a nominal 18 - 22 day ground track repeat cycle (depending on satellite) with 15 imaging orbits per day. Each orbit plane is phased around the Earth with a different local time of ascending node (LTAN) and descending node (LTDN). This means that the constellation as a whole has the ability to observe a location at different times of the day rather than the more conventional dawn-dusk sun-synchronous orbit.
This mission is considered a Third Party Mission under evaluation. The evaluation will tackle cal/val activities and assess the products specifications. This analysis will be performed in the framework of the Earthnet Data Assessment Pilot (EDAP). The evaluation will also allow any interested users to investigate the suitability of the data for scientific and R&D activities.
The flexibility of the satellites facilitates imaging modes to be constantly evolved. Currently, the satellites operate in two modes called 'Spotlight Mode' and 'Stripmap Mode'.
|Nominal Altitude||560 to 580 km|
|Orbits / Day||15|
|Ground track repeat||18-22 days|
|Constellation mean revisit at equator||20 hours|
|Nodal crossing||22:30, 13:00, 13:04, 14:54|
ICEYE's overall mission objective is to enable better decision making by providing timely and reliable Earth observation data. The company has been developing its own synthetic-aperture radar sensor technologies suitable for satellites under 100 kg in weight.
Synthetic Aperture Radar (SAR)
Each radar pulse can be digitally programmed to modulate over a bandwidth between 37.6 and 300 MHz centred on the X-band (9.65 GHz) part of the spectrum. The pulse repetition frequency (PRF) can be selected between 2 and 10 kHz and the peak transmitted power can be as much as 3.2 kW.
The active phased array antenna can provide electronic beam steering. This is used in addition to the satellite's mechanical agility to point a radar beam precisely onto the Earth's surface. This agility also allows the beam to be directed towards the right or left side of the satellite track.
The instrument's nominal operating parameters are detailed in the table.
|Carrier frequency||9.65 GHz (X-band)|
|Look direction||both LEFT and RIGHT|
|Antenna size||3.2 m (along-track) x 0.4 m|
|Range Bandwidth||37.6-300 MHz|
|Peak Radiated Power||3.2 kW|
|Incidence angle range||15-35 (mode dependent)|
|Communication (radar payload data downlink)||X-band 140 Mbits/s|
The flexibility of the satellites facilitates imaging modes to be constantly evolved. Currently, the satellites operate in two primary modes called 'Spotlight Mode' and 'Stripmap Mode' with each mode providing different output imaging capabilities depending on tasking and exploitation requirements, as detailed in the table.
|Nominal swath width||30||5|
|Nominal product length||50||5|
|Incidence angle (scene centre)||15-30°||20-35°|
|NESZ (dBm2/m2)||-21.5 to -20||-18 to -15|
|AASR (dB)& RASR (dB)||-15 & -20||-15 & -20|
|Slant range resolution (m)||0.5 to 2.5||0.5|
|Slant azimuth resolution (m)||3||0.25|
|Slant range spacing (m)||0.4 to 2.4||0.4|
|Slant azimuth spacing (m)||1.6||0.2|
|Ground range resolution (m)||3||1|
|Ground azimuth resolution (m)||3||1|
|Ground range spacing (m)||2.5||0.5|
|Ground azimuth spacing (m)||2.5||0.5|
|Range looks||1 to 2||4|
|ESA Copernicus Contributing Mission (CCM) Resolution Class (6)||VHR2||VHR1|
ESA is offering, for scientific research and application development, access to archive and new tasking data from the SkySat mission upon submission and acceptance of a project proposal. These products are available as part of the Planet imagery offer. ESA will support as many high-quality and innovative projects as possible within the quota limit available, therefore only a limited amount of products can be made available to each project. The data distribution of this collection is currently "under assessment" but the description of data collection is available:
The data distribution of this collection is currently "under assessment" but the description of data collection is available:
A basic ICEYE product is represented by a set of SAR image binary data along with the corresponding image annotation metadata, delivered as a singular product package. Products are characterized by the payload configuration (such as imaging mode and look direction) used by the respective satellite, as well as the level of processing that has been applied to the SAR scene. With respect to the data geometric projection and representation, Basic Image Products are differentiated into two primary product types, Single Look Complex (SLC) and Ground Range Detected (GRD).
Also, ICEYE currently provides a Level 2 product that is geocoded called Ellipsoid Corrected (EC). This product is a multi-looked, detected product which has been resampled and projected onto a reference ellipsoid with a mean scene centre altitude being applied. The product is provided in a Universal Transverse Mercator (UTM) map projection. No terrain correction is performed and there is no geometric correction applied using a Digital Elevation Model (DEM). This product is ideally suited for mapping applications and can easily be draped over a DEM, map or external image product using the encoded metadata.
ICEYE Data Format
ICEYE data are stored and delivered in HDF5 files (SLC data) and GeoTiff files (GRD data and Geocoded products). HDF5 format is particularly suitable for storing binary complex SAR data channels along with annotated metadata. On the other hand, GeoTiff images are readily readable by common GIS software tools. Additionally, both SLC and GRD products are accompanied by xml-files containing metadata, thus enabling quick screening of products without the use of specialized software.
Detailed description of storage format for SLC data is given in ICEYE Basic Product Format Specification Document available from ICEYE website. Georeferenced ICEYE products are readable using specialised SAR software (e.g., ESA SNAP - S1TBX) where product orthorectification and further processing can be performed.
|Stripmap||HDF5, XML||GeoTiff, XML||GeoTiff, XML||0.9 - 2.8||PNG, KML|
|Stripmap High||HDF5, XML||GeoTiff, XML||GeoTiff, XML||2.8||PNG, KML|
|Spotlight||HDF5, XML||GeoTiff, XML||GeoTiff, XML||0.6||PNG, KML|
|Spotlight High||HDF5, XML||GeoTiff, XML||GeoTiff, XML||2.8||PNG, KML|