Create more specific beam group descriptions for EK80

[b-reyes]

In PR #658 it was found that the beam group descriptions for EK80 can become more specific.

As it stands right now, we let the Beam_group1 description be "contains backscatter data (either complex samples or uncalibrated power samples) and other beam or channel-specific data".

To be more explicit, we can let the Beam_group1 description be:

• When only power data exists:
  • "contains backscatter power (uncalibrated) and other beam or channel-specific data."
• When complex samples exist:
  • "contains complex backscatter data and other beam or channel-specific data."

I have a rough idea of how we can accomplish this.

1. Modify beamgroups_possible (in EK80) to:

beamgroups_possible = [
        {
            "name": "Beam_group1",
            "descr":
                {
                    'power': "contains backscatter power (uncalibrated) and "
                             "other beam or channel-specific data.",
                    'complex': "contains complex backscatter data and other "
                               "beam or channel-specific data."
                 },
        },
        {
            "name": "Beam_group2",
            "descr": (
                "contains backscatter power (uncalibrated) and other beam or channel-specific data,"  # noqa
                " including split-beam angle data when they exist."
            ),
        },
    ]

2. Replace

https://github.com/OSOceanAcoustics/echopype/blob/e0b3cbff9459b57cc8320388cc1ac86da6063343/echopype/convert/api.py#L461-L470

with

    beam_group_type = []
    for idx, beam_group in enumerate(beam_groups, start=1):
        if beam_group is not None:
            beam_group_type.append("complex" if "backscatter_i" in beam_group else "power")
            tree_dict[f"Sonar/Beam_group{idx}"] = beam_group


    if sonar_model in ["EK80", "ES80", "EA640"]:
        tree_dict["Sonar"] = setgrouper.set_sonar(beam_group_type=beam_group_type)
    else:
        tree_dict["Sonar"] = setgrouper.set_sonar()

3. In set_sonar (for EK80) let

(https://github.com/OSOceanAcoustics/echopype/blob/e0b3cbff9459b57cc8320388cc1ac86da6063343/echopype/convert/set_groups_ek80.py#L174)

become

beam1_val = beamgroups_possible[0]
beam1_val['descr'] = beam1_val['descr']['complex'] 
self._beamgroups = [beam1_val] + beamgroups_possible[1:]

@emiliom what do you think?

[emiliom]

Thanks @b-reyes ! Sorry, I won't comment on it until we're on the other side of 0.6.0.

Note: this issue is related to #625

[leewujung]

Related to #719 and its upcoming implementation which will include changes like what's proposed above but for AD2CP.

[leewujung]

@b-reyes : could you take care of this and #625? The description are very similar and probably is a duplication or heavily overlap. Thanks.

[b-reyes]

@b-reyes : could you take care of this and #625? The description are very similar and probably is a duplication or heavily overlap. Thanks.

I have looked back into this and it seems this issue is specifically discussing changes to the beam group descriptions. On the other hand, #625 is more concerned with where the repr pulls the beam group descriptions from.

To proceed with this issue, I think it is good to have @emiliom review my proposed solution above. If he thinks the solution is appropriate, I will implement it. In the meantime, I can do a PR for #625.