A new datum or geospatial reference system is being introduced in the United States to become the official datum in 2022. At GIS in the Rockies, Pam Fromhertz of the NOAA National Geodetic Survey gave an overview of the reasoning behind the new datum, technical details about the change and some practical implications.
Most people in the geospatial sector in the U.S. are aware of the datums NAD27 and NAD83 which have been the reference points for all surveys performed in the U.S. NAD83 was defined primarily using terrestrial surveying techniques. NAD83 has been updated several times since being introduced in 1983 but is based on an ellipsoid that is non-geocentric and is tilted slightly. The new datum or North American Terrestrial Reference Frame of 2022 (NATRF2022) is based on gravity which means that “sea level” is now represented by an equipotential gravity surface rather than the Earth’s ellipsoid. The new reference frames will rely primarily on Global Navigation Satellite Systems (GNSS) such as the Global Positioning System (GPS) as well as an updated and time-tracked geoid model. Importantly, the new datum means that Mexico, Canada, and the U.S. will share a common datum. The gravity-based vertical datum will be accurate at the 2 cm level for much of the U.S. Gravity data is currently being captured across the U.S. and its territories as part of the Grav-D project.
Practically, this means that elevations may change by up to a meter and horizontal location by up to 1.5 meters. The actual corrections to elevations and horizontal locations will depend on where you are in North America. The greatest changes are in the Pacific Northwest and the least in the southeastern U.S. At the hotel in Inverness, Colorado where the GIS in the Rockies conference took place this year, the corrections were 1.36 m horizontally and -0.67 m vertically. The NOAA National Geodetic Survey web site (geodesy.noaa.gov) has tools to perform conversions from NAD83 to the new 2022 datum.
The Survey of India (SOI) has launched new web portal called Nakshe to make open series maps available to Indians for free.
Organization : Survey of India (SOI)
Founder: East India Company
The portal was launched by Union Minister for Science & Technology and Earth Sciences, Harsh Vardhan on the occasion of 250th anniversary of SOI.
Features of Nakshe Portal
It will offer a free download of 3,000 Topographic maps or Open Series Maps (OSM) in a pdf format on 1:50,000 scale through Aaadhar enabled user authentication process. The maps are meant for development activities in the country and can be also used to plan scientific expeditions, research, and planning development projects. Topographic maps or OSM comprise natural and man-made geographical features including terrain or topography.
Note: Foundation for the scientific survey and mapping of the country was laid with The Great Trigonometric Survey (GTS) in the 19th century on 10th April 1802, by noted surveyors Col. Lambton and Sir George Everest. Interestingly, Everest has been named after former Surveyor General of India Col Sir George Everest. The measurement of the world’s highest peak has been made by the SoI.
Indian Space Research Organisation (ISRO) and US space agency, NASA will jointly launch a satellite to monitor climate change and deformations in the Earth’s crust. Named NASA-ISRO Synthetic Aperture Radar, or NISAR, the satellite will help study earthquakes and their patterns. It will observe and take measurements of ecosystem disturbances, ice-sheet collapse, and other natural hazards like tsunamis, volcanoes and landslides.
However, there is some disagreement over the day of the lauch. While USA said that it was ready to launch the satellite on 2020-21, ISRO is contemplating pre-poning it. NASA administrator Charles Frank Bolden said,”The US is providing L-Band. It will help us look at crustal deformation. We are looking for hints at earthquake detection. We cannot predict
NASA administrator Charles Frank Bolden said,”The US is providing L-Band. It will help us look at crustal deformation. We are looking for hints at earthquake detection. We cannot predict earthquake but we can advise people where it has occurred. We are hoping to launch it by 2020-21.” ISRO’s AS Kiran Kumar, said that the project will not only help in understanding the seismic activity, but also help in monitoring agricultural activities in India. Kumar further added,”The activity involves building a payload with L- and S- bands synthetic aperture radar. It’s a new technology instrument.
While NASA provides the L-Band component of the electronics plus the antenna, which is a huge one. ISRO will provide the S-Band and the payload will be integrated at NASA and then the payload comes back at Bangalore. It gets integrated on the satellite, which is being built and will be launched by ISRO.”
“So, currently the activities are going on in full swing. Both the governments have cleared the basic mission. We are looking at a possible launch with 2021. We are trying to advance the launch and we are working towards it. As far as we are concerned the usage of this got many significant usage for our programme.” “We are very much excited about it because for the first time two of our agencies are working together on such a big scale,” the ISRO chief said. He further added that both the space agencies have formed a working group and they would meet periodically.
There are various software available (commercial as well as open source/freeware) for processing Geospatial data. Here is the alphabetical list of open source software related to Geoscience and Remote Sensing.
Approximate Nearest Neighbors (ANN) is a library written in the C++ programming language to support both exact and approximate nearest neighbor searching in spaces of various dimensions.
The MapReady Remote Sensing Tool Kit accepts level 1 detected SAR data, single look complex SAR data, and optical data from ASF and some other facilities. It can terrain correct, geocode, apply polarimetric decompositions to multi-pol SAR data, and save to several common imagery formats including GeoTIFF. Other software included in the package are an image viewer, metadata viewer, a projection coordinate converter, and a variety of command line tools.
ASF SAR Training Processor
The SAR Training Processor (STP) is a graphical tool written to assist in learning and teaching the flow of SAR processing.
BEAM is a toolbox for viewing, analyzing and processing of remote sensing data.
Matlab Collection by Beril Sirmacek
This collection includes matlab codes for active shape growing 2D box fit, intensity value based box fit, shadow detection, and color invariant features for Object (Road) Detection.
A package of programs for the determination of canopy geometry and solar radiation regimes through hemispherical photographs.
Monitoring tropical deforestation and forest degradation with satellites can be an everyday activity for non-experts who support environmental conservation, forest management, and resource policy development. Through extensive observation of user needs, we developed CLASlite to assist governments, nongovernmental organizations, and academic institutions with high-resolution mapping and monitoring of forests with satellite imagery.
Climate Resilience Toolkit
Tools are available to help you manage your climate-related risks and opportunities, and to help guide you in building resilience to extreme events.
3D point cloud and mesh processing software.
and many more. Please download the complete list from here