3vGeomatics’ Post

InSAR, also known as Interferometric Synthetic Aperture Radar, is a satellite-based technology that employs radar to detect changes in the Earth's surface. The radar transmits pulses and collects the resulting reflections, including details on intensity and phase. By comparing pairs of images taken at different times, the phase data is utilized to identify any shifts in the ground or man-made structures. Learn more about the benefits of using InSAR for your projects: https://loom.ly/QPaf5Yk #3vG #3vGeomatics #InSAR #radar #satellite #geotechnicalinstrumentation #datacollection #historicalanalysis #learnmore

When planning a project, historical data can used to retroactively investigate areas of interest or to establish a baseline for ongoing projects. Radar satellites have been collecting images around the globe since the early 1990’s. Urban and rural locations worldwide have archive data available for InSAR analyses. 3vG can conduct a data archive search of all relevant satellite image databases to determine data availability over your specific area of interest. If sufficient imagery is available, we can conduct an InSAR analysis of these images to measure displacement over the associated time frame. Learn more about InSAR: https://loom.ly/QPaf5Yk #3vg #3vgeomatics #insar #motionary #displacementdatastream #historicalanalysis #learnmore

🛰️ Advancing Land Cover Classification Techniques: Combining Optical and Radar Satellites Imagery Utilizing Spectral and Texture Features I've successfully integrated multi-satellite data to enhance land cover classification accuracy. 🔍 Key Findings:  • Achieved remarkable 0,90 overall accuracy and 0,88 KAPPA coefficient through the synergistic combination of Sentinel-1 (SAR) and Sentinel-2 (optical) data • Leveraged complementary strengths: - Optical satellites provided critical spectral indices (NDVI, NDWI, EVI, NDBI, etc) - Radar data contributed valuable textural features using GLCM metrics (ASM, ENT, etc.) The combined approach improved classification accuracy compared to single-source imagery (90% accuracy for multi-source combinations vs 78% and 88% for single source) This methodology represents a significant advancement in land cover mapping, particularly for tropical regions where cloud cover often limits traditional optical-only approaches. The findings demonstrate how integrating multiple satellite data sources can overcome the limitations of individual sensors. #RemoteSensing #GIS #DataScience #Geospatial #SatelliteImagery #MachineLearning

𝗚𝗡𝗦𝗦 𝗘𝗿𝗿𝗼𝗿 𝘀𝗼𝘂𝗿𝗰𝗲 𝗮𝗻𝗱 𝗺𝗼𝗱𝗲𝗿𝗻 𝗠𝗶𝘁𝗶𝗴𝗮𝘁𝗶𝗼𝗻 𝘁𝗲𝗰𝗵𝗻𝗶𝗾𝘂𝗲. Global Navigation Satellite Systems (GNSS) are indispensable for various applications, yet their accuracy can be affected by several error sources. Understanding these errors and the modern mitigation techniques is crucial for enhancing positional precision. 𝗠𝗮𝗷𝗼𝗿 𝗦𝗼𝘂𝗿𝗰𝗲𝘀 𝗼𝗳 𝗚𝗡𝗦𝗦 𝗣𝗼𝘀𝗶𝘁𝗶𝗼𝗻𝗶𝗻𝗴 𝗘𝗿𝗿𝗼𝗿𝘀: 1. Ionospheric Delays: As GNSS signals pass through the ionosphere, they experience delays due to ionized particles, leading to positional inaccuracies. 2. Tropospheric Delays: Variations in temperature, pressure, and humidity in the troposphere can slow down GNSS signals, introducing errors in position calculations. 3. Satellite Clock and Orbit Errors: Inaccuracies in satellite clocks or deviations in their orbits can introduce timing errors, affecting positional accuracy. 4. Multipath Effects: Signals reflecting off surfaces like buildings or water can cause the receiver to process both direct and reflected signals, resulting in erroneous position calculations. 5. Receiver Noise: Internal noise within the GNSS receiver can introduce small errors in the position solution. 𝗠𝗼𝗱𝗲𝗿𝗻 𝗠𝗶𝘁𝗶𝗴𝗮𝘁𝗶𝗼𝗻 𝗧𝗲𝗰𝗵𝗻𝗶𝗾𝘂𝗲𝘀 To mitigate/eliminate these errors, advanced correction methods are widely used today: 1. Differential GNSS (DGNSS) How it works: A base station at a known location calculates corrections by comparing its measured position to its actual position. These corrections are transmitted to rover receivers. Basically it's the same concept design used for RTK but corrections services it's less expensive than RTK ones, and distance between rover and base can be higher compared to RTK. Accuracy: DGNSS improves accuracy to sub-meter levels, mitigating atmospheric errors and satellite inaccuracies. 2. Real-Time Kinematic (RTK) How it works: RTK relies on a base station to provide real-time corrections to rover receivers using carrier phase measurements. Accuracy: Achieves centimeter-level accuracy by resolving carrier phase ambiguities.

Key Differences Between GPS and DGPS In GPS, there is a standalone receiver which receives signals from the satellite whereas in DGPS there are two receivers, reference receiver and rover (user) where rover receives a calibrated signal from the reference receiver (fixed base station). The accuracy of GPS system is around 15 meters. On the other hand, DGPS is more accurate and can achieve accuracy up to 10 cm. GPS instruments cover the wide range and can be used globally while DGPS instruments cover a short range up to 100 km, but this range could change according to the frequency band. GPS system is less expensive as compared to DGPS system. The signal frequency transmitted by satellites in GPS ranges between 1.1 to 1.5 GHz. On the contrary, in DGPS the satellites do not transmit fixed range of frequency, the transmitted frequency depends on the agencies. The factors that affect the accuracy of the GPS system are selective availability, satellite timing, atmospheric conditions, ionosphere, troposphere and multipath. In contrast, the DGPS system is affected by the distance between the transmitter and rover, ionosphere, troposphere and multipath but at less extent. The GPS uses WGS84 time coordinate system which is an earth-fixed terrestrial system, earth-centred, and geodetic datum. As against DGPS uses a local coordinate system.

Synthetic aperture radar constellations are expanding in response to growing public and private demand.

𝗛𝗼𝘄 𝗥𝗧𝗞 𝗘𝗿𝗿𝗼𝗿 𝗖𝗼𝗿𝗿𝗲𝗰𝘁𝗶𝗼𝗻𝘀 𝗪𝗼𝗿𝗸 🎯 _... • Behind the scenes, RTK relies on a network of GNSS satellites that transmit signals to both the base station and the mobile receiver. The base station, positioned at a stable, fixed location with visibility to satellite constellations and within radio range of the rover, continuously calculates the discrepancies between its precise coordinates and the coordinates obtained from GNSS signals. These discrepancies, or errors, include factors such as 𝘀𝗮𝘁𝗲𝗹𝗹𝗶𝘁𝗲 𝗼𝗿𝗯𝗶𝘁 𝗲𝗿𝗿𝗼𝗿𝘀, 𝗮𝘁𝗺𝗼𝘀𝗽𝗵𝗲𝗿𝗶𝗰 𝗱𝗲𝗹𝗮𝘆𝘀, 𝗮𝗻𝗱 𝗺𝘂𝗹𝘁𝗶𝗽𝗮𝘁𝗵 𝗲𝗳𝗳𝗲𝗰𝘁𝘀, which occur when signals reflect off surfaces before reaching the receiver. • The base station sends real-time correction data to the mobile receiver, which applies these corrections to its own measurements. This process involves several key steps: 𝟭. 𝗗𝗶𝗳𝗳𝗲𝗿𝗲𝗻𝘁𝗶𝗮𝗹 𝗖𝗼𝗿𝗿𝗲𝗰𝘁𝗶𝗼𝗻𝘀 – The base station calculates the difference between the observed GNSS measurements and the true position, generating differential corrections. 𝟮. 𝗥𝗲𝗮𝗹-𝗧𝗶𝗺𝗲 𝗧𝗿𝗮𝗻𝘀𝗺𝗶𝘀𝘀𝗶𝗼𝗻 – These corrections are transmitted to the mobile receiver via radio signals, enabling immediate adjustments. 𝟯. 𝗣𝗼𝘀𝗶𝘁𝗶𝗼𝗻 𝗥𝗲𝗳𝗶𝗻𝗲𝗺𝗲𝗻𝘁 – The mobile receiver applies the corrections to refine its position estimates, resulting in highly accurate coordinates. • To maintain optimal performance, it is crucial that the error in RTK positioning remains minimal—typically within a few centimeters. If the error exceeds this acceptable range, adjustments or recalibrations may be necessary to ensure measurement accuracy. Also Check: ▪️"𝗥𝗧𝗞 𝗣𝗼𝘀𝗶𝘁𝗶𝗼𝗻𝗶𝗻𝗴 𝗘𝘅𝗽𝗹𝗮𝗶𝗻𝗲𝗱" ----https://lnkd.in/d9K2bxsC ▪️"𝗥𝗧𝗞 🆚 𝗣𝗣𝗞" ----https://lnkd.in/d9rWPcgK 🔻𝗦𝗵𝗮𝗿𝗲 𝘆𝗼𝘂𝗿 𝗽𝗲𝗿𝘀𝗽𝗲𝗰𝘁𝗶𝘃𝗲 👇🏾 🔻Follow 👉🏾: Gensre Engineering & Research #RTK #GNSS #GeodeticSurvey #ErrorCorrection #RealTimeKinematic #DifferentialCorrections #SurveyingTechniques #Geospatial #Construction #GIS Video Credit 🎥: Geospatial World & SatLab

#WGIC_Member_Spotlight | 💬 "By leveraging remote sensing, we identified the specific composition of treated water. When we capture images and analyze signals beneath the ground, we can detect leakages based on the presence of water. Our system is developed based on actual soil data collected globally, allowing for accurate leakage detection," said Lauren Guy, Founder & CTO ASTERRA, in an interview with WGIC's Bhanu Rekha. 📍ASTERRA uses synthetic aperture radar (SAR) to detect underground indications of leakages. Most remote sensing satellites operate within the optical spectrum, but ASTERRA utilizes the #microwave_spectrum. 📽️ Watch the full interview here: https://lnkd.in/dT-cB69d #WGIC #ASTERRA #RemoteSensing #SAR #GeospatialTechnology #GeospatialIndustry 

TorchGeo version 0.6 introduces 18 new datasets, 15 additional data modules, and 27 new pre-trained models compatible with images from RGB, SAR, MSI, or HSI satellites/sensors #machinelearning https://lnkd.in/dpKSHa9p

In the coming days, we will participate in the Small Satellite Conference to be held in Salt Lake City in 2025. To further strengthen our involvement in this market, ARESYS is preparing a series of papers on newly developed products: X-band Micro SAR Electronics, Light SAR On-board Processor, and Gigabit X-band Payload Data Transmission. As the SmallSat market rapidly expands, ARESYS is pioneering advanced SAR technology for small satellites. We spoke with our 𝗕𝘂𝘀𝗶𝗻𝗲𝘀𝘀 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁 𝗠𝗮𝗻𝗮𝗴𝗲𝗿, Fabio Gerace, to learn more about ARESYS’s vision and innovations in this field. 𝗧𝗵𝗲 𝗦𝗺𝗮𝗹𝗹𝗦𝗮𝘁 𝗺𝗮𝗿𝗸𝗲𝘁 𝗶𝘀 𝗿𝗮𝗽𝗶𝗱𝗹𝘆 𝗲𝘅𝗽𝗮𝗻𝗱𝗶𝗻𝗴. 𝗪𝗵𝗮𝘁 𝗿𝗼𝗹𝗲 𝗱𝗼𝗲𝘀 𝗔𝗥𝗘𝗦𝗬𝗦 𝗽𝗹𝗮𝘆 𝗶𝗻 𝘁𝗵𝗶𝘀 𝗲𝘃𝗼𝗹𝘃𝗶𝗻𝗴 𝘀𝗲𝗰𝘁𝗼𝗿? "ARESYS is actively developing advanced solutions to meet new user needs. Our focus is on designing high-performance Synthetic Aperture Radar (SAR) payloads optimized specifically for small satellites and designed for large Earth observation constellations. Our goal is to make Earth observation more powerful and cost-effective, enabling greater accessibility to satellite data," says Fabio. 𝗪𝗵𝗮𝘁 𝗮𝗿𝗲 𝘁𝗵𝗲 𝗰𝗼𝗻𝗰𝗿𝗲𝘁𝗲 𝗮𝗽𝗽𝗹𝗶𝗰𝗮𝘁𝗶𝗼𝗻𝘀 𝗮𝗻𝗱 𝗯𝗲𝗻𝗲𝗳𝗶𝘁𝘀 𝗼𝗳 𝘁𝗵𝗲𝘀𝗲 𝘁𝗲𝗰𝗵𝗻𝗼𝗹𝗼𝗴𝗶𝗲𝘀? "We are currently engaged in strategic collaborations to provide high-precision imaging with SmallSats, expanding data acquisition capabilities across various applications. These next-generation SAR payloads support a wide range of uses, from environmental management to security and urban planning." 𝗪𝗵𝗮𝘁 𝗶𝘀 𝗔𝗥𝗘𝗦𝗬𝗦'𝘀 𝗺𝗼𝘀𝘁 𝗶𝗻𝗻𝗼𝘃𝗮𝘁𝗶𝘃𝗲 𝗼𝗻𝗴𝗼𝗶𝗻𝗴 𝗽𝗿𝗼𝗷𝗲𝗰𝘁 𝗶𝗻 𝘁𝗵𝗲 𝗳𝗶𝗲𝗹𝗱 𝗮𝗻𝗱 𝘄𝗵𝗮𝘁 𝘀𝗲𝘁𝘀 𝗶𝘁 𝗮𝗽𝗮𝗿𝘁 𝗳𝗿𝗼𝗺 𝗼𝘁𝗵𝗲𝗿 𝗱𝗲𝘃𝗲𝗹𝗼𝗽𝗺𝗲𝗻𝘁𝘀? "The X-band Micro #SAR Electronics is an innovative electronics and RF component of a SAR payload designed, developed, and qualified by ARESYS at TRL 6. It is intended for use on small satellites (starting from 40 kg) capable of acquiring SAR images in various modes, including Stripmap, Spotlight, SIMO, and #MIMO (in swarm) configurations." #SpaceTech #SmallSat #EarthObservation #SatelliteImaging