Everything a senior engineer would bring to the bench.

The Irregular Terrain Model the professionals use, at the reliability level you specify, with the terrain roughness measured from USGS elevation data around your actual site instead of guessed from a menu. Plus Hata, COST-231, and Egli for quick estimates.

Give it two coordinates and it pulls the actual USGS elevation profile between them, sampled about every 10 meters, runs Longley-Rice point-to-point, and tells you line of sight or obstructed, the loss and the received level. Set the far end's receiver from the TIA antenna tables or by hand, give it a threshold, and you get the margin. Turn on talk-back and the return link is solved at the same time, so a link that talks out fine but cannot be heard back shows up before the truck roll. A side view draws the terrain with the earth bulge, the direct ray and the first Fresnel zone, so an obstructed verdict shows you where the ground gets close.

One transmitter and a whole list of receive points: storm sirens, SCADA outstations, fire-station alerting receivers. Upload the list as a spreadsheet export, click the points on the map, or type them, and each one comes back with a predicted level, a margin, and a pass, marginal or fail. Every site gets its own Longley-Rice solve over the real terrain profile between it and the tower, not a reading taken off a painted coverage grid, because a siren on a known pole height deserves the actual profile. Heights and antenna gains can differ per site while everything else stays shared, so the points compare like for like. The reliable-signal threshold is yours to supply, since that number is the decoder's sensitivity plus the fade margin your contract calls for, and nothing is invented on your behalf. Turn on talk-back and each site is solved in reverse for acknowledgements and outstation reports. The whole survey prints as one letterheaded document: the site map colored by verdict, and the table ordered weakest first so the points that need attention are on page one.

A full fixed-microwave link budget between two sites: free space and gaseous loss, antenna gains, EIRP, receive signal, and fade margin, with Vigants-Barnett multipath and ITU-R P.530 rain availability worked out to the worst-month and annual percentages, and a side-view profile showing the direct ray, first Fresnel zone, and earth bulge.

The propagation map runs a Longley-Rice radial sweep over real USGS ground profiles, up to 360 radials, and draws the actual irregular coverage polygon: shorter into the ridge, longer down the valley, with forest and built-up clutter from land cover data figured in at the receive end.

A contour answers how far. This answers how good, and where: signal levels over real USGS ground profiles, painted bin by bin into usage classes from a portable inside a building to a mobile on a roof antenna, with the square miles each covers. No class floor is invented. Each is your receiver threshold plus the antenna correction the TIA standard tabulates for that band plus the loss you enter, and the page shows that arithmetic.

Upload a pattern file (MSI Planet or NSMA) or give a beamwidth, point the boresight, set the tilt, and the contours and tile studies follow the pattern instead of assuming omni. Patterns live in a shared library for the whole operation.

The public-safety coverage-acceptance method: a uniform tile grid, a real Longley-Rice median for every tile, and predicted area reliability against your target, using the channel performance criterion you enter from the TSB-88 revision you design against. Bound the study to the area you actually serve, traced on the map or uploaded as GeoJSON or a shapefile, and reliability averages over those tiles instead of a circle. Interferers, co-channel or adjacent, apply the receiver's own rejection.

Any study on a map page saves under a name and the customer it belongs to: the site, the antenna, the thresholds, the environment, and for a receive-site survey the whole list of points. Load it months later, change the one thing that moved, and either save over it or keep the original and save a copy. Only the inputs are stored, never the results, so a reopened study recomputes against today's FCC data and today's terrain instead of showing numbers whose age nobody can tell. The form marks itself edited the moment you change anything, and asks before it throws unsaved changes away.

Every propagation study, channel search, short-spacing study, and TOWAIR screen prints or downloads as a PDF under your operation's name: parameters, results, the map, and the planning-study disclaimers, kept in a report history and ready to hand a customer or attach to a coordination request.

Third and fifth order products against your site frequency list, so interference turns up on paper rather than in a complaint. The list builds itself: click a tower and every licensed land mobile frequency loads from FCC data, along with the FM and TV stations on the site, because a 100 kW FM carrier is usually the strongest mixer on the tower and ULS cannot see it. Receive inputs are derived by band offset and labeled as convention, never guessed, and the report shows which frequencies came from where.

The study a frequency coordinator runs before anyone files: does the proposed base station clear every incumbent the rules protect? Pick the license at a site and its frequency, power and heights load as filed, or enter a new station by hand. The study applies the FCC rule for the band: the 800 and 900 MHz separation table with the contour pair it came from, the forward and reciprocal adjacent-channel analyses on the 800 MHz interstitial channels with the interference levels the rule tabulates by emission, and the VHF and UHF service-versus-interference contour test. Contours are drawn on the FCC's own propagation curves at the height above average terrain of every radial, incumbents come from the ULS copy, and the result names each station that passes, fails, or needs a letter of concurrence, with the map and a letterheaded report to attach to the request.

Zone radius, the 60% clearance rule, earth bulge, and the diffraction cost of that ridge or tree line near the path.

Ground rod resistance from soil and rod dimensions, and antenna-to-antenna isolation from vertical or horizontal separation for repeater planning.

Fade margin to edge and area coverage percentages, receiver noise floor, sensitivity conversions, RF exposure per OET-65, VSWR, and ERP.

Two pre-construction screens apply before a tower goes up, and the second is the one shops miss. FAA screening answers whether the FAA needs notice. AM protection answers whether a nearby broadcast station does: within a wavelength of a nondirectional station and over 60 electrical degrees tall, or within the lesser of ten wavelengths or three kilometers of a directional one and over 36. Notice is due 30 days before construction, and both screens run off the same coordinates against live FCC data.

Two things a co-located site needs that one transmitter at a time will never tell you. RF exposure summed across every emitter on the tower, each against its own frequency limit, because sources that pass alone can be over the line together. And a desense budget: transmitter noise landing in the receive channel, front-end blocking, the receiver's thermal floor, and how many dB of isolation the site is short. Both work from your measured numbers.

Coax loss by cable type and run length, dBm/watts/microvolt conversions, PL and DPL tone tables, emission designator decoding, audio line levels, DC voltage-drop, and battery runtime.

Put your licenses, and your customers', on a watch list by callsign or FRN, one at a time or imported straight from a spreadsheet. Sentinel RF checks every one against each weekly FCC data refresh.

Automatic expiration alerts at 180, 90, and 30 days out, delivered in the app and by email, the way a diligent office manager would catch them.

Construction notification deadlines sit right beside the renewal dates: the earliest unfiled deadline on each license, the days left, and alerts at 90 days, 30 days, and overdue. An unfiled buildout can cost the license, so it gets the same attention an expiration does.

Add a structure by its ASR number, or add your owner FRN and pick up every tower registered to you at once, with newly registered ones joining on their own. Name each site the way your crew does, not by its registration number.

Alerts when a watched structure changes owner, changes status, or changes height, and when an application is filed against its registration. That last one is the earliest warning there is, because a filing lands before the registration itself changes. It matters whether you own the tower and lease space out or just have gear on someone else's: a site going up for dismantlement is not something to learn from a field visit.

When a top light or flashing beacon fails on a registered tower, the owner has to report it and the FAA issues an obstruction NOTAM that carries the ASR number. Sentinel RF pulls the FAA's NOTAM feed every twenty minutes, matches it against your watched towers and areas, and alerts you when a NOTAM is issued, extended, cancelled, or expires. Where the FAA left the ASR number off, the tower is matched by its coordinates. For the operation that maintains the lighting, that is a service call within the hour instead of a compliance problem weeks later.

When a light fails, log it against the structure and the platform writes the report Flight Service asks for: ASR number, coordinates, height, the light that failed, the nearest airport and your return-to-service date. It tracks the 30-minute reporting window in 47 CFR 17.48, confirms from the FAA feed that the NOTAM actually appeared, reminds you before the NOTAM expires while the light is still out, and closes the record when the cancellation shows up. Every step is timestamped, so each structure carries its own compliance history.

Every license whose transmit site is that structure, listed against it. This is the FCC's own record of who is on the tower, not a guess from nearby coordinates, so it is worth trusting for a tenant audit or a co-location question.

Define an area and stay aware of new antenna-structure applications and grants inside it. A simple, weekly heads-up on what is being proposed or built nearby, useful for planning, coordination, and local awareness.

Set an area and a frequency band, and get notified when a new license is granted or applied for nearby: the coordination and interference check a system operator actually needs.

Define the area as a simple radius, a polygon you trace on the map, or a boundary you upload as GeoJSON or a shapefile, reprojected for you automatically.

Renewal windows, expirations, status changes, and new-activity alerts collect in one place, so nothing depends on one person remembering to check.

Hold the mic button in the chat bar and talk. It works in every browser, so a tech with a probe in one hand can still ask a question.

For general or background questions, an optional open-web fallback can be turned on. It is clearly labeled and never used to answer a spec or a procedure.

Upload your logo once and it prints at the top of every study report, so what you hand a customer looks like it came from you. If the logo already carries your name, tell Sentinel RF and it leaves the printed name off rather than saying it twice.

Share a conversation with one person by name, or with the whole operation. A named share is a handoff, so they get a bell notification and an email with a link to the chat; a share to everyone lands in each seat's bell without the email. They read the thread, its citations, and its attachments, and only the owner can add to it. Chats stay inside your operation; nothing can be shared across operations.

Each seat can turn on an authenticator app, a passkey or recovery codes from their own profile, and admin seats are required to have one. Tick remember me on a machine you own and it stays signed in for thirty days instead of asking again every day; leave it unticked on a shared bench computer and the session ends in twenty four hours. One active session per person, so signing in somewhere else ends the old one.

Owner, admin, and member roles keep control where it belongs. Each person signs in with their own seat; credentials are never shared.

Add or remove seats from the admin console with prorated changes previewed before you confirm, and manage billing from a self-serve portal.

See usage by seat and an audit log of who did what, so an owner can run the operation instead of running the software.

Your documents stay isolated to your operation and are never used to answer another operation's questions. Export your data any time from the admin console.

The platform is actively monitored for health and reliability, with automated offsite backups, so your library and history stay safe.