ForHosting KIT · Developer Utilities

Terrain line of sight calculator

Line of sight over terrain is the geometric question behind radio links, rifle ranges, trail cameras, drone paths, and simple viewshed checks when you already hold a height profile along a path.

● BetaFree · in your browser

Run — free How it works & API

Use it from WebAPIEmailTelegramApp soon

This terrain line of sight calculator takes an ordered series of ground elevations from observer to target, plus the height of the eye or antenna above the first sample and the height of the object above the last sample, and reports whether the straight ray clears every intervening sample. The model is flat-Earth with equal horizontal spacing between profile points—fast, deterministic, and easy to wire into scripts that already extracted elevations from a DEM or survey. When the ray dips below the ground at any sample the response marks the path blocked and names the first blocking index. The same pure module powers the free browser widget and the API, so field tools and automation never disagree on a clearance by a millimetre of floating noise.

How to use it

Enter your values in the form above. The tool checks them before calculating and shows the result on the same page.

Check your inputs

Use the labels and units shown next to each field. If something is missing or outside the allowed range, the page points to the field to fix.

Use it again or automate it

Use the browser tool for individual checks and the API when you need the same capability in an automated workflow.

What you can do with it

Get an answer now

Enter one set of values and see the result without building a spreadsheet or script.

Compare scenarios

Change one value at a time and rerun the calculation to understand what affects the result.

Automate repeated work

Use the API when the same calculation needs to run inside your product or workflow.

FAQ

How do I use this capability?

Complete the fields above and run it on this page. The form highlights anything that needs attention.

For developers — API access

Everything on this page is available programmatically. This section is for teams who want to wire it into their own systems; everyone else can just use the tool above.

API endpoint

POSThttps://api.kit.forhosting.com/geo/line-of-sight

Prefer to automate it? One authenticated POST creates the task; the result comes back by webhook or a signed link. The same capability also runs here on the web, by email and from Telegram — and soon from our app too.

Call it from your stack

curl -X POST https://api.kit.forhosting.com/geo/line-of-sight \
  -H "Authorization: Bearer $KIT_KEY" \
  -H "Content-Type: application/json" \
  -d '{"profile":[100,105,120,110,95],"observer_height":1.7,"target_height":0}'

const res = await fetch("https://api.kit.forhosting.com/geo/line-of-sight", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${process.env.KIT_KEY}`,
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    "profile": [
      100,
      105,
      120,
      110,
      95
    ],
    "observer_height": 1.7,
    "target_height": 0
  })
});
const { task_id } = await res.json();

import os, requests

res = requests.post(
    "https://api.kit.forhosting.com/geo/line-of-sight",
    headers={"Authorization": f"Bearer {os.environ['KIT_KEY']}"},
    json={
    "profile": [
        100,
        105,
        120,
        110,
        95
    ],
    "observer_height": 1.7,
    "target_height": 0
},
)
task_id = res.json()["task_id"]

<?php
$res = file_get_contents("https://api.kit.forhosting.com/geo/line-of-sight", false, stream_context_create([
  "http" => [
    "method"  => "POST",
    "header"  => "Authorization: Bearer " . getenv("KIT_KEY") . "\r\nContent-Type: application/json",
    "content" => '{"profile":[100,105,120,110,95],"observer_height":1.7,"target_height":0}',
  ],
]));
$task = json_decode($res, true);

body := bytes.NewBufferString(`{"profile":[100,105,120,110,95],"observer_height":1.7,"target_height":0}`)
req, _ := http.NewRequest("POST", "https://api.kit.forhosting.com/geo/line-of-sight", body)
req.Header.Set("Authorization", "Bearer "+os.Getenv("KIT_KEY"))
req.Header.Set("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)

Example request

{
  "profile": [
    100,
    105,
    120,
    110,
    95
  ],
  "observer_height": 1.7,
  "target_height": 0
}

Example response

{
  "task_id": "tsk_a1b2c3d4e5f6a1b2c3d4e5f6",
  "type": "geo.line_of_sight",
  "status": "queued",
  "_links": {
    "result": "/tasks/tsk_…/result"
  }
}

The API is asynchronous: the call returns a task_id immediately and the result arrives by webhook. Polling is capped at 1 req/s per task.

Pricing

Per request$0.002

Published price — no tokens, no invented credits. A failed task is never charged.

Errors

HTTP	Code	Meaning
`401`	`unauthorized`	Missing or invalid API key.
`402`	`insufficient_balance`	Your balance doesn't cover the task price.
`404`	`unknown_type`	That task type doesn't exist.
`429`	`rate_limited`	Too many requests. Use the webhook instead of polling.

Read the full KIT documentation →