# Cadcorp SIS

The Cadcorp Spatial Information System® (Cadcorp SIS®) is an integrated family of geospatial products comprising desktop, web, and developer applications.

Cadcorp SIS Desktop connects directly to the OS Data Hub through dedicated wizards.

## What you need

* Cadcorp SIS (version SIS 9 or later).
* A preloaded base map, for example, [OS Maps API](https://app.gitbook.com/s/oEzqrBzRGoJw7nQyLj1W/accessing-os-apis/os-maps-api "mention") or [OS Vector Tile API](https://app.gitbook.com/s/oEzqrBzRGoJw7nQyLj1W/accessing-os-apis/os-vector-tile-api "mention").
* OS NGD API – Features added to an API project in the OS Data Hub with an API Key. See [Getting started with an API project](https://app.gitbook.com/s/oEzqrBzRGoJw7nQyLj1W/core-concepts/getting-started-with-an-api-project "mention") for more information. 

## Instructions

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These instructions are based on Cadcorp SIS Desktop version 9.1.1668.
{% endhint %}

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### Add overlay

Once a new map has been set up, in the Home tab, click *Add Overlay*.

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FpvWwns4tOeMp43jOWadj%2FAdd-Overlay-Wizard.png?alt=media&#x26;token=417fe335-71ba-4b2f-864a-4f58a156fdeb" alt="Cadcorp SIS Desktop UI highlighting Add Overlay button."><figcaption><p>Cadcorp SIS Desktop UI highlighting <em>Add Overlay</em> button.</p></figcaption></figure>
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{% step %}

### Select API

In the Overlay Types dialog:

* Select *Ordnance Survey (GB) > OS (GB) Data Hub*, and then click *Next*.

In the OS (GB) Data Hub dialog:

* Select *OS National Geographic Database (NGD) API* – *Features.*
* **API Key**: Enter your API key.
* **Premium/Public Sector Plan**: Select this option if you have this plan.
* **Save in the UI settings database (encrypted)**: Select this option.
* Click *Next*.

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FbcYEvvsR4y5no1eTIHUC%2FOSGB-Data-Hub-Overlay-Types.png?alt=media&#x26;token=0df7b114-5917-41cb-95b5-3d97a4416397" alt="Cadcorp SIS Desktop OS (GB) Data Hub dialog with the Next button and API Key button highlighted."><figcaption><p>Cadcorp SIS Desktop OS (GB) Data Hub dialog</p></figcaption></figure>
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{% step %}

### Adding layers to the map

In the OS Data Hub NGD API – Features Data Themes and Feature Types dialog:

* **Well-known ‘recipe**’: Select a predefined recipe, if available.
* **Data Themes**: Select your data themes.
* **Features**: If necessary, use the editing tools (on the right) to delete feature types or to change the order in which they display in your SIS Workspace Definition (SWD).\
  \&#xNAN;*By default, all feature types within the selected data themes are available in the right panel.*&#x20;
* **Local cache**: Select this option to store the data temporarily on your machine. \
  \&#xNAN;*If you save and reopen the SWD, the data will still be available as it is fetched from your local cache.*
* **One-off import**: Select this option to do a one-off import of the data. \
  \&#xNAN;*If you save and reopen the SWD, the data will not be available and you will need to re-import it. These imports have a larger file size.*
* **Filtering**: \
  \&#xNAN;*These settings are used in conjunction and define how much data is required for display. It is recommended that you always set a spatial filter and feature limit.*
  * **Spatial**: The *Intersect with current view extent* option limits the download to only selected features within the current window extent. \
    \&#xNAN;*You can also load features within a specific area of interest using the polygon feature to draw your area of interest on the map BEFORE opening the Add Overlay dialog.*
  * **Maximum number of features**: Limits the number of feature values downloaded to the number set. \
    \&#xNAN;*This limit is applied per feature within any filtered spatial area.*
* Click *Finish*.

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FPsyaKcjKUTKoKZMXfsgK%2FOS-NGD-Features-Recipe.png?alt=media&#x26;token=9aa62fc1-2f61-4ccd-8b24-d64d7a35fd29" alt=""><figcaption></figcaption></figure>

*The selected layer(s) will then display in the* SIS Workspace Definition (SWD) *and the data will display in the map area:*

<figure><img src="https://170091638-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0pZjHxkAvY7Mn6TqFBMD%2Fuploads%2FcnguVGYP19E2GlwkI7wb%2FOS-NGD-Features.png?alt=media&#x26;token=f2458aea-48e3-4227-a6ac-8aa548652826" alt="Cadcorp SIS Desktop UI showing OS NGD API – Features data in the map area."><figcaption><p>Cadcorp SIS Desktop UI showing OS NGD API – Features data.</p></figcaption></figure>
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