Temperature
August 29, 2024
-
Rosa Schmidt
Toulouse, one of France's hottest cities, is grappling with extreme temperatures, reaching up to 41 degrees Celsius this summer. Toulouse, often referred to as the "City of Art and History," is celebrated for its rich architectural heritage, featuring a mix of styles under one sky. Its unique geographical position at the crossroads between the Atlantic and theMediterranean significantly influences how light is emitted, and heat is stored within the city.
Known for enduring the hottest summer on record last year, Toulouse continues to face intense heat, prompting local officials to seek innovative solutions to manage rising temperatures. This blend of architectural diversity and geographical positioning makes monitoring Urban Heat Islands (UHIs) particularly crucial.
One of the tools aiding in this effort is thermal intelligence from satellite imagery, specifically from the constellr’s upcoming HiVE datasets. These data sets sharpened to a 10-meter resolution, combine thermal and visible imagery to monitor Urban Heat Islands (UHIs) effectively. They provide:
· High temperature accuracy for reliable user data
· High frequency / Temporal resolution to allow continuous monitoring of UHI dynamics over time
· Spatial resolution to track specific hotspot in the region and city
The creation of these advanced thermal images begins with the hardware aboard constellr's satellites. These satellites are equipped with cutting-edge sensors capable of capturing detailed thermal data and data from the visible and near-infrared(VNIR) part of the spectrum. This dual approach allows cities like Toulouse to monitor and respond to their unique heat challenges effectively.
What Are VNIR and Thermal Infrared Sensors?
When you snap a photo with a standard phone camera, you can instantly view a clear image. However, this is not the case with a scientifically graded thermal imager, such as HiVE’s. For example, take a look at the raw imagery near Toulouse airport from our HiVE thermal imager(simulated). The airport and the nearby river features are hardly distinguishable until post-processing is applied. If you are curious about how we transform this raw data into a detailed image, be sure to follow our series of articles where we dive into our post-processing techniques!
.png)
The VNIR sensor on constellr’s satellites is similar to the Sentinel-2 mission, capturing data in the visible and near-infrared spectrum. VNIR data provides crucial contextual information, helping to interpret thermal data accurately by identifying specific features on the ground, such as rivers, vegetation, and urban areas. This is essential for ensuring that temperature measurements are precisely linked to specific locations on Earth.
On the other hand, Thermal Infrared (TIR) sensors capture the heat emitted by objects on the Earth's surface. This data is critical for detecting temperature variations and identifying hotspots. However, raw thermal images can be challenging to interpret without the contextual information provided by VNIR data.
For example, a raw thermal image near Toulouse airport might show indistinct features, making it difficult to differentiate between the airport runways and nearby rivers. However, when VNIR data is combined with thermal data, these features become clear, allowing for precise analysis.
The Importance of VNIR in Enhancing Thermal Data
VNIR data plays a pivotal role in enhancing the usability of thermal images. Without VNIR support, interpreting thermal data can be challenging, as features that appear similar in temperature might look very different in VNIR imagery. This contrast helps analysts pinpoint the exact location and nature of heat anomalies, providing a more accurate understanding of urban heat patterns.
For example, comparing a standard RGB image with a VNIR-enhanced image near Toulouse airport shows how VNIR data can highlight differences in vegetation, water bodies, and built-up areas. This differentiation is crucial for accurate thermal analysis, ensuring that hotspots are correctly located and identified.
The Future of Urban Heat Monitoring in Toulouse
By providing location-accurate and measurement-accurate temperature data, constellr's HiVE datasets offer a powerful tool for urban planners and environmental researchers. These datasets can be used independently or integrated with other data layers to explore specific user scenarios. For instance, overlaying Land Surface Temperature (LST) data on Google Earth imagery reveals potential hotspots in urban areas, offering valuable insights for applications ranging from urban planning to agricultural monitoring.
As Toulouse continues to face extreme heat, the integration of advanced satellite data into city planning processes will be crucial. constellr's HiVE technology will represent a significant step forward in understanding and mitigating the impacts of Urban Heat Islands, helping cities like Toulouse adapt to the challenges of a warming world.
