About HotSat-1
HotSat-1, launched in June 2023, (and operational until December 2023) is a cutting-edge satellite developed by British company Satellite Vu (SatVu).
The satellite is the first of its kind to offer commercially available high-resolution thermal infrared imaging of Earth. It is designed to track heat variations from industries, infrastructure and other assets, providing valuable insights into energy efficiency, environmental monitoring, and the impacts of climate change
The satellite's primary mission is to collect the highest resolution thermal data from space for a safer and more sustainable Earth. The images captured by SatVu’s first satellite, HotSat-1, show heat variations across the surface of the earth at a resolution of up to 3.5 m, both during the day and at night. Thermal data at this unparalleled resolution has wide applications, from economic monitoring and national security to climate resilience including urban heat monitoring.
HotSat-1 is the first in a planned constellation of nine satellites which SatVu has envisaged for consistent monitoring of thermal emissions on Earth.
After suffering a technical anomaly in December 2023, the satellite ceased operating. However, the second and third satellites of the constellation are planned for launch in the upcoming year.
Until ceasing operation, HotSat-1 was able to image the same location every 1-2 days while orbiting the Earth at an altitude of 500 km. The satellite communicated with a global network of ground stations to receive tasking requests and deliver data, with a downlink speed of 450 Mbps.
Applicants will be given access to SatVu’s self-service platform which allows users to browse their existing data catalogue. The data can be downloaded on a scene-by-scene basis, with each scene covering an area of 16 km2 (3.5km x 4.5km). The files are delivered as cloud-optimised GeoTIFFs of, on average, 10 MB and are accompanied by metadata following the STAC specification.
| Orbit Type | Sun synchronous |
| Orbit Altitude | 500 km |
| Ascending Node | 00:39 |
| Spacecraft Weight | 130 kg |
| Swath (Standard Scene Size) | 4.5 km (across-track) x 3.5 km (along-track) |
| Orbit Off-Nadir Angle (ONA) | 0-45° |
| Ground Sampling Distance (GSD) | 3.5 m (nadir) to 6.8 m (45° ONA) |
| Spectral Band | Night: 3.7-5 μm Day: 4.5-5 μm |
| Revisit Frequency (40° latitude) | 1 day (45° max. ONA) to 2 days (30° max ONA) |
| Sensor Sensitivity | < 2 K |
| Capacity | 200 scenes per day |
| Dynamic Range | 16 bit |
| Georeferencing Accuracy | 30 m CE90 without ground control |
Objectives
The primary objectives of HotSat-1 are to provide high-resolution thermal infrared imaging of the Earth. The satellite aims to monitor heat variations from industry and infrastructure to support activity monitoring, security intelligence, and climate impact analysis.
The satellite's frequent revisits to the same location allowed for near daily data collection, aiding in applications such as industrial activity monitoring and energy management. The data is intended to help identify areas of energy loss, monitor industrial activity, and support various sectors in managing environmental and energy-related challenges.
Instruments
HotSat-1 uses a MWIR (Mid Wave InfraRed) imaging sensor that captures heat emissions from the Earth's surface. The instrument was designed and supplied by the Italian company Leonardo and has an array of pixels on an 8 μm pitch – the smallest thermal MWIR pixels commercially available at the time of development.
Each scene is captured with a ground sampling distance (GSD) of between 3.5 metres and 6.8 metres depending on the imaging angle. Specifically, the sensor measures the intensity of this radiation to determine temperature differences as small as 2°C or better.
Two modes are possible which allow for both daytime and nighttime image capture. At night, the sensor is sensitive to radiation in the range 3.7-5 μm; during daylight hours, a filter is applied to reduce noise from reflected solar radiation, giving a range of 4.5-5 μm for daytime imaging.
Data
DATA COLLECTION
The European Space Agency (ESA) is offering, through a dedicated Announcement of Opportunity, access to the HotSat-1 product archive to support the scientific community.