# Applications of Satellite Radar Imagery for Hazard Monitoring: Insights from Australia
## 7 Geomorphological Changes
### Example Case-Study: Geomorphological Monitoring in Remote Areas (Northern Territory)
Grey regions are those in A with absolute LoS velocities >15 mm/yr in magnitude and show that these regions are proximal to the large topographic gradients. In both of these locations, InSAR provides high-resolution measurements of surface changes, the characterisation of which provides key inputs into future plans for safe infrastructure development. However, satellite SAR observations require validation with field-based measurements to verify the cause of the observed signals and determine whether they result from weathering, sediment ablation/deposition, or shrinking/swelling in response to hydrological changes. Consequently, whilst there is promise for InSAR data to contribute to the study of geomorphological hazards, more validation is required to fully understand the link between the observed signals and geomorphological processes. 8 Discussion: Future Opportunities for Developing the Role of SAR for Hazard Monitoring in Australia  
Over the last decade, a persistent message from the government and industry has been that SAR data are too expensive to be an economically viable tool for hazard (and other) monitoring and investigation, particularly over regional scales (e.g., [35; 38]). As is the case for other countries globally, Australia's capacity to use SAR data for hazard monitoring applications will therefore be largely dependent upon the availability of open-access data from existing and new sensors. Significantly, Sentinel-1 is the first satellite constellation to change the paradigm of the past years, providing wall-to-wall continental-scale coverage of open-access SAR data in Australia at regular repeat intervals. As is demonstrated in case studies here, this can be bolstered by access to additional commercial datasets, for example, at a higher spatial resolution, from pay-to-use satellite missions, which are now utilising smaller, lower-cost satellite platforms to reduce the cost of SAR data (e.g., ICEYE: Table S2). In addition to data availability, progress towards the operational use of SAR in hazard monitoring by national and state government agencies in Australia (and elsewhere) will benefit from a number of other factors. The first of these is data access: downloading Sentinel-1 datasets from European/North American-based datacentres is problematic in the Asia-Pacific region, and therefore, a local data access node, the Sentinel Australia Regional Access (SARA) hub ([[https://copernicus.nci.org.au/sara.client/#/home--accessed](https://copernicus.nci.org.au/sara.client/#/home--accessed)]([https://copernicus.nci.org.au/sara.client/#/home--accessed](https://copernicus.nci.org.au/sara.client/#/home--accessed)) on 16 March 2021), has been implemented to mirror all Sentinel-1 data acquired over the Asia-Pacific region and significantly expedite local data download times. Standardised data formats or 'Analysis Ready Data' (ARD) products (for example as defined for SAR by the Committee on Earth Observation Satellites ARD for Land, CARD4L, initiative: [78]), standardised data platforms, and standardised analysis tools built upon open-access software (e.g., the SAR DataCube: [10]) will also support increased uptake of SAR data. Accordingly, plans for the inclusion of Sentinel-1 SAR data within DEA are underway and will further enable users to take advantage of this systematically acquired and openly available resource. Other resources include automated generation of InSAR products, e.g., seismic events, as described in Section 6. Crucially, the planned follow-on Sentinel-1 satellites (Sentinel-1C and D), plus Sentinel-1 Next Generation, will promote the longevity of any operational analysis tools developed for these data. The consistent and systematic data provided by Sentinel-1 presents opportunities to implement SAR as a systematic tool (either operational or experimental) for monitoring and understanding the hazards described in this study.