SIGNALERT App vs Terrain Elevation Profile

SIGNALERT is an information-sharing and crowdmapping application allowing each one of us to report, be warned and monitor the impact of natural or man-made disasters, the effects of climate change, extreme events or crisis that impacts us, our environment, or of which we are witnesses or victims. Locate your observation, take a picture, and answer a few simple questions to describe the intensity level of the phenomenon and its impact. Give your own observations. That's all. Send and share the alert, in return, get a map of observations by other witnesses and App users around you. Natural phenomena to describe are: Earthquake, Cyclone/hurricane/typhoon, Floods, Rockfalls, Landslide, Avalanches, Snowfall, Wildfires, Storm Surge, Tornado, Tsunami, Volcanic Eruption, Heatwave, Drought, High Temperature, Heavy Rainfall, Locust invasion And man-made phenomena: Marine and coastal pollution, Unauthorized dumps, Road/Rail accidents, Fire-Explosion, Air Quality, Troubles and violence, Attack, Health Crisis SIGNALERT allows you to exchange in real time, with other users of the app, the effects of such phenomena, that are just starting and may become dangerous in your field of vision or beyond, from wherever you are in the world. The app also gives you tips about appropriate behaviors for each phenomenon, and will instruct you about how to recognize the intensity level and impact, and offers links to the institutional websites of forecasts, warning or monitoring worldwide. Once sent an alert with the App you can share it on social networks. The paid version is your personal or community warning system nearby: • Choose which worldwide places of interest you want to monitor and automatically receive real-time notifications for any alert sent nearby by other users. • Use the "I am safe" button to report to your loved ones or relatives, that you are not in danger if you are the witness of a disastrous situation. • Receive real-time warning notifications or alerts of flooding on monitored river sections close to your sites of interest (works in France for now, soon in other countries), exceeded temperatures thresholds or extreme rainfall based on open data from internet of things (works better in countries with dense networks of connected objects and may not give any results if no sensor with shared open data in the neighbourhood). Create your own monitoring network between neighbours, and relay the proximity alerts whenever a member of your network detects a potentially harmful phenomenon nearby. When traveling, you can find in the app websites of official national or international institutions in charge of weather and extreme event forecasts, reports and monitoring. The app is available in French, English, Spanish, Arabic and other languages soon. You can change or cancel your subscription (automatic renewal) in settings of your account on the application. The payment is made via your iTunes account. Privacy policy and terms of use : http://content.signalert.net/cgu-fr.html#privacy

Viewshed & Line of Sight is a terrain visibility analysis app that shows what can and cannot be seen from any location on Earth using elevation data. Plan, explore and analyze terrain with clear visual tools for visibility and line of sight. KEY FEATURES Viewshed analysis * Generate visibility maps from any location * Free up to 5 km radius * Premium up to 30 km radius Line of sight analysis * Check visibility between any two points up to 500 km * Identify whether terrain blocks or allows visibility Terrain profiles (premium) * View elevation changes between points * See peaks along a path * Export terrain profile to CSV Search and navigation * Search locations and coordinates * Explore locations worldwide instantly Export and data tools (premium) * Export viewshed maps * Export terrain profiles * Export CSV data for further analysis PREMIUM FEATURES * Higher resolution 30 m terrain data (limited to North America, EU without Greece and Finland, Japan and New Zealand) * Improved accuracy for visibility analysis * Extended viewshed range up to 30 km * Advanced terrain profile tools and exports USES CASES * Hiking and outdoor exploration * Radio and antenna planning * Telecom and network analysis * GIS and mapping projects * Photography and viewpoint scouting NOTE Results are based on digital elevation models and may not include buildings, vegetation or temporary obstacles.