Frequently Asked Questions

Questions that have come up more than once, mostly from the issue tracker.

The insarhub-app link will not open

insarhub-app prints a URL such as http://127.0.0.1:8080, but the browser shows nothing — a connection error, a blank page, or someone else's application.

Port 8080 is a popular default, so something else on the machine has very likely taken it. Start the app somewhere else:

insarhub-app --port 12345

Then open the URL the app prints, not the old one. Any free port works.

Other things worth checking

• Open the URL it printed. With --host 0.0.0.0 the app is reachable from other machines, but the address to type is still the host's own.
• Remote or HPC sessions. If insarhub-app runs on a remote machine, forward the port first: ssh -L 12345:127.0.0.1:12345 user@host, then open http://127.0.0.1:12345 on your own computer.
• Blank page rather than a connection error. That means the server is up but the frontend bundle is missing — reinstall InSARHub, and see Installation.

Search finds scenes, but Download fails with "Search does not return any result"

Fixed in 0.4.0 (#7). Upgrade:

conda install -c conda-forge insarhub

asf_search 13.0.0 changed how it decides which frame field a query means. Its should_use_asf_frame() stopped recognising a generic platform=SENTINEL-1 search, so the frame filter silently queried the ESA frame number and matched nothing — which is why searching worked while downloading found zero scenes. InSARHub now routes frame filters to asfFrame explicitly, which behaves the same on asf_search 12.x and 13.x.

If you previously pinned asf_search=12.3.2 as a workaround, you can lift the pin.

ISCE2 stops part-way through and the terminal process disappears

Two different causes, and they look identical from the outside.

A silent crash at a fixed step was a bug in 0.3.x (#6): _fix_cmd failed to strip the trailing & that ISCE2 writes into every run_files line, so the command returned instantly with success while its real work was orphaned. Fixed in 0.4.0.

A crash at a varying step, often on a large stack, is usually the kernel's OOM killer. InSARHub runs each run_files line in parallel, and several ISCE2 steps are memory-hungry, so the total can exceed RAM. Lower the concurrency:

insarhub processor -N ISCE2_S1 -w /path/to/workdir submit --max_workers 2

--max_workers is the knob for every step except topo (run_01), which is a single command — use --num_proc4topo for that one. See Processor.

Telling the two apart

Run with INSARHUB_DEBUG=1 and check executor.log in the work directory. An OOM kill leaves the step at RUNNING with no error, and dmesg | grep -i "killed process" names the process. See Logging.

What does pip install -e . install?

The trailing dot is required — it means "the package in the current directory" (#2). Activate the environment first, and run it from the repository root:

conda activate insarhub
cd InSARHub
pip install -e .

-e is an editable install: the environment points at your checkout, so code changes take effect without reinstalling. You only need this to work on InSARHub itself — to simply use it, install from conda-forge as in Installation.

Which satellites are supported?

Sentinel-1 and NISAR today (#1):

Product	Search & download	Processing
Sentinel-1 SLC	yes	HyP3, ISCE2, GMTSAR
Sentinel-1 Burst	yes	ISCE3 / COMPASS + dolphin
NISAR GSLC	yes	ISCE3 + dolphin
NISAR RSLC, GUNW	yes	not yet — no processor consumes them

NISAR RSLC and GUNW are hidden in the web UI for that reason: they would download a large volume of data that nothing can then process. They remain available from the CLI and the Python API.

ALOS, ERS and other platforms are not supported yet.

How do I see what InSARHub is doing?

It is quiet by default — only the command's output, plus warnings and errors. Set INSARHUB_DEBUG=1 for the full log:

INSARHUB_DEBUG=1 insarhub processor -N ISCE2_S1 -w /path/to/workdir submit

This works for the CLI, insarhub-app and import insarhub alike. Details in Logging.

--select-pair warns that no pair graph will be generated

Expected for S1_Burst and the NISAR products. ASF publishes no perpendicular baseline for them, so a baseline-vs-time network cannot be drawn.

The pairs are still created, and processing is unaffected: the ISCE3 processors build their own interferogram network through dolphin's phase linking, using temporal and index constraints rather than a perpendicular-baseline threshold. See Pair Quality Scoring.